Merge pull request 'fix(engine): resize pile-marker outline and watermark children on relayout' (#131) from fix/pile-marker-child-resize into master

Found during Fold 7 on-device verification of v0.41.0: on_window_resized
resized the marker fill sprite but never its children, so after any
resize (fold/unfold, rotation) the outline frame and the A/K watermark
kept their spawn-time size — rendering as oversized grey slabs over the
empty foundation slots.

The resize handler now re-derives both children from the new layout
(outline = card_size + 2*PILE_MARKER_OUTLINE_WIDTH, watermark font =
card_size.x * 0.28 — same formulas as spawn). Adds a regression test
and an Android-gated relayout log line (width/height/insets) as the
evidence channel for the remaining foldable layout bug (#130).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.cargo/config.toml

@@ -0,0 +1,5 @@
+[registries.Quaternions]
+index = "sparse+https://git.aleshym.co/api/packages/Quaternions/cargo/"
+
+[target.wasm32-unknown-unknown]
+rustflags = ['--cfg', 'getrandom_backend="wasm_js"']

.gitea/workflows/docker-build.yml

@@ -6,10 +6,14 @@ on:
     branches: [master]
     paths:
       - 'solitaire_server/**'
+      - 'solitaire_wasm/**'
+      - 'solitaire_web/**'
       - 'solitaire_sync/**'
       - 'solitaire_core/**'
+      - 'solitaire_engine/**'
       - 'Cargo.toml'
       - 'Cargo.lock'
+      - 'solitaire_server/Dockerfile'
       - '.gitea/workflows/docker-build.yml'
 
 env:
@@ -32,6 +36,13 @@ jobs:
         id: meta
         run: echo "sha=${GITHUB_SHA::8}" >> "$GITHUB_OUTPUT"
 
+      # WASM artifact freshness is owned by the `web-wasm-rebuild` workflow,
+      # which rebuilds pkg/ in CI on every master change to a wasm-feeding crate
+      # and commits it back (CI is the single source of truth — the artifacts
+      # aren't byte-reproducible on contributor machines). That pkg/ commit then
+      # triggers this workflow, so the deployed image always ships fresh wasm.
+      # No drift check is needed here.
+
       - name: Log in to Gitea registry
         uses: docker/login-action@v3
         with:

.gitea/workflows/web-e2e.yml

@@ -0,0 +1,62 @@
+name: Web E2E
+
+on:
+  push:
+    branches: [master]
+    paths:
+      - 'solitaire_server/web/**'
+      - 'solitaire_server/src/**'
+      - 'solitaire_server/e2e/**'
+      - 'solitaire_wasm/**'
+      - 'solitaire_core/**'
+      - 'Cargo.toml'
+      - 'Cargo.lock'
+      - '.gitea/workflows/web-e2e.yml'
+  workflow_dispatch:
+
+jobs:
+  web-e2e:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Cache cargo build
+        uses: Swatinem/rust-cache@v2
+
+      # Prebuild the server so Playwright's `webServer` (which runs
+      # `cargo run -p solitaire_server`) starts from a compiled binary instead
+      # of cold-compiling the whole dependency graph (axum/sqlx/reqwest) inside
+      # its 120s startup window — the timeout that was failing every run.
+      # SQLX_OFFLINE uses the checked-in `.sqlx/` query cache (no live DB).
+      - name: Prebuild server
+        env:
+          SQLX_OFFLINE: 'true'
+        run: cargo build -p solitaire_server --quiet
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20'
+          cache: 'npm'
+          cache-dependency-path: solitaire_server/e2e/package-lock.json
+
+      - name: Install e2e dependencies
+        working-directory: solitaire_server/e2e
+        run: npm ci
+
+      - name: Install Playwright browser
+        working-directory: solitaire_server/e2e
+        run: npx playwright install --with-deps chromium
+
+      - name: Run web e2e tests
+        working-directory: solitaire_server/e2e
+        run: npm test
+
+      - name: Run cycle regression gate
+        working-directory: solitaire_server/e2e
+        run: npm run review:cycles:regression

.gitea/workflows/web-wasm-rebuild.yml

@@ -0,0 +1,89 @@
+name: Web WASM Rebuild
+
+# CI is the single source of truth for solitaire_server/web/pkg/.
+#
+# The wasm artifacts cannot be reproduced byte-for-byte on an arbitrary
+# contributor machine: even with identical rustc 1.95.0 / LLVM 22.1.2, the same
+# flags, the same Cargo.lock and remapped source paths, the output still differs
+# by host environment. So rather than police freshness with a rebuild-and-diff
+# gate (which false-failed for exactly that reason), CI rebuilds the artifacts
+# itself on every master change to a wasm-feeding crate and commits them back.
+#
+# Result: the deployed pkg/ can't silently rot, and contributors never need to
+# run build_wasm.sh by hand. The commit touches only pkg/, which is not in this
+# workflow's trigger paths (so it does not re-trigger here) but does match
+# docker-build's, so the refreshed wasm deploys.
+
+on:
+  push:
+    branches: [master]
+    paths:
+      - 'solitaire_core/**'
+      - 'solitaire_engine/**'
+      - 'solitaire_data/**'
+      - 'solitaire_sync/**'
+      - 'solitaire_wasm/**'
+      - 'solitaire_web/**'
+      - 'Cargo.toml'
+      - 'Cargo.lock'
+      - 'build_wasm.sh'
+      - '.gitea/workflows/web-wasm-rebuild.yml'
+  workflow_dispatch:
+
+concurrency:
+  group: web-wasm-rebuild
+  cancel-in-progress: false
+
+jobs:
+  rebuild:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+          token: ${{ secrets.CI_TOKEN }}
+
+      - name: Install Rust 1.95.0
+        uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: 1.95.0
+          targets: wasm32-unknown-unknown
+
+      - name: Cache cargo build
+        uses: Swatinem/rust-cache@v2
+
+      - name: Install wasm-bindgen-cli + wasm-pack (pinned)
+        uses: taiki-e/install-action@v2
+        with:
+          tool: wasm-bindgen-cli@0.2.120,wasm-pack@0.14.0
+
+      - name: Install binaryen 130 (wasm-opt, pinned)
+        run: |
+          set -euo pipefail
+          curl -sSL \
+            https://github.com/WebAssembly/binaryen/releases/download/version_130/binaryen-version_130-x86_64-linux.tar.gz \
+            | tar xz
+          echo "$PWD/binaryen-version_130/bin" >> "$GITHUB_PATH"
+
+      - name: Rebuild WASM artifacts
+        run: ./build_wasm.sh
+
+      - name: Commit refreshed artifacts if changed
+        run: |
+          set -euo pipefail
+          if git diff --quiet -- solitaire_server/web/pkg/; then
+            echo "pkg/ already up to date — nothing to commit."
+            exit 0
+          fi
+          git config user.email "ci@gitea.local"
+          git config user.name "Gitea CI"
+          git add solitaire_server/web/pkg/
+          git commit -m "chore(web): regenerate wasm artifacts"
+          # master is unprotected; retry once if the tip moved under us.
+          git push origin HEAD:master || {
+            git fetch origin master
+            git rebase origin/master
+            git push origin HEAD:master
+          }

.gitignore

@@ -15,6 +15,11 @@ agentdb.rvf.lock
 # IDE project files
 .idea/
 
+# Browser e2e harness artifacts
+solitaire_server/e2e/node_modules/
+solitaire_server/e2e/playwright-report/
+solitaire_server/e2e/test-results/
+
 # Android signing keystores — never commit
 *.jks
 *.jks.bak
@@ -25,3 +30,14 @@ agentdb.rvf.lock
 deploy/matomo-secret.yaml
 deploy/*-secret.yaml
 deploy/*-auth-secret.yaml
+
+# Local agent-tooling artifacts (Codex / claude-flow) — keep out of the repo
+/.agents/
+/.codex/
+/AGENTS.md
+# claude-flow scratch dirs, anywhere in the tree (e.g. solitaire_engine/src/)
+.claude-flow/
+
+# Local token-saving helper scripts (peek/cargoclip/testfail/diffclip/etc.) —
+# inspection-only Go tools, not committed. Tracked scripts/*.sh and *.md stay.
+scripts/*.go

ARCHITECTURE.md

@@ -109,6 +109,18 @@ Owns:
 - Achievement unlock condition evaluation
 - Seeded RNG for reproducible deals
 
+**Rules decisions:**
+- **Stock recycling is unlimited in every draw mode — by design.** Extra
+  passes through the stock are discouraged via the upstream score penalty
+  (applied by the `card_game`/`klondike` session), never blocked with a
+  `MoveError`. This matches mainstream digital solitaire (unlimited redeals
+  in Draw-1) rather than strict tournament rules (3-pass cap). It is load-
+  bearing: the difficulty seed catalog and the winnable-deal solver are
+  verified under unlimited recycling, so introducing a hard pass limit would
+  invalidate both. Locked in by the
+  `draw_one_recycling_is_unlimited_by_design` test in
+  `solitaire_core/src/game_state.rs`. (Decision record: Gitea issue #117.)
+
 ### `solitaire_sync`
 **Dependencies:** `serde`, `serde_json`, `uuid`, `chrono` only.
 

CHANGELOG.md

@@ -6,6 +6,320 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
+## [0.41.0] — 2026-07-06
+
+> Consolidates everything shipped since v0.39.0, including the v0.40.0–v0.40.3
+> patch tags (which were cut from this section without renaming it at the time).
+
+### Added
+
+- **Rules decision record: unlimited stock recycling.** Documented in
+  `ARCHITECTURE.md` that unlimited recycling with score penalties (matching
+  mainstream digital solitaire) is intentional, and locked it in with a core
+  test — the difficulty seed catalog and winnable-deal solver are verified
+  under this rule. Resolves the last open finding from the June 500-game
+  audit (issue #117).
+- **Analytics validation runbook.** Documented native Matomo live validation,
+  expected event payloads, and the current web/WASM analytics split.
+- **Android smoke-test runbook.** Updated the Android doc with the current
+  platform status, support matrix, and a physical-device
+  launch/touch/safe-area checklist.
+- **Browser Bevy canvas route and automation support.** Added the `solitaire_web`
+  Bevy WASM build, wired `/play` to the Bevy canvas, added a
+  `window.__FERROUS_DEBUG__` bridge, and introduced Playwright coverage for the
+  web routes and interactive canvas behavior.
+- **Card-game / klondike integration.** Began replacing in-house card and pile
+  internals with upstream `card_game` / `klondike` types, including adapter
+  work, GameMode-aware scoring, upstream instruction serde, `KlondikePile`
+  migration, and documentation for the in-place rewrite phases.
+- **Android keystore integration.** Added Android Keystore JNI wiring via
+  `OnceLock` and improved Android token handling around the app directory.
+
+### Changed
+
+- **Engine plugin modules restructured.** The five oversized plugin files
+  (card, hud, settings, game, input) are now module directories with their
+  test suites in sibling `tests.rs` files — no behaviour change; first phase
+  of the module-split plan (#118).
+- **Core type ownership.** Routed all klondike/card imports through
+  `solitaire_core` and unified local `Suit` / `Rank` with upstream `card_game`
+  types.
+- **Web/WASM build reliability.** Rebuilt WASM packages, cleaned up wasm32 build
+  warnings, added a Binaryen `wasm-opt` pass, pinned upstream git dependencies,
+  and added a CI guard for canvas WASM drift.
+- **Difficulty seed catalog.** Regenerated the difficulty seed list for the
+  latest verified catalog.
+
+### Fixed
+
+- **Safe-area insets now re-polled after app resume.** The inset poller settled
+  permanently once insets first resolved, so inset changes while backgrounded
+  (fold/unfold, rotation, gesture ↔ 3-button nav switch) kept stale layout until
+  the app was killed. Each resume now re-arms a fresh poll window; the cached
+  value is rewritten only when it actually changed, so unchanged resumes still
+  cause no relayout flash. (#116)
+- **Tableau fill on foldables / tall screens.** The tableau fan now spreads from
+  each column's total depth (face-down cards included) and refills on the
+  cold-start deal, every move, and on resize (incl. the Android safe-area-inset
+  resize and fold/unfold), so a near-square viewport such as an unfolded Galaxy
+  Fold no longer leaves the bottom of the screen empty. The fan spread cap was
+  raised so very tall / narrow viewports (e.g. a foldable cover screen) fill
+  further.
+- **Card-move animation jank.** A move now rebuilds a card's child visuals only
+  when its appearance changes (flip / resize / accessibility) instead of
+  despawning and respawning every card's children each `StateChangedEvent`,
+  removing the per-move spike that stuttered the slide animation on
+  high-resolution devices.
+- **Android and modal safe-area layout.** Modal cards now center within the
+  usable area between status and gesture bars, additional modal-spawn guards were
+  added, and Android build scripts now auto-discover SDK/NDK paths and strip
+  native libraries.
+- **Core scoring and undo correctness.** Fixed recycle-count drift, undo score
+  compounding, foundation-to-tableau instruction coverage, and several
+  illegal-move paths discovered during the card-game migration.
+- **Input and rendering issues.** Fixed stock/waste hit testing, accepted waste
+  clicks, delayed first-run onboarding until splash teardown, and kept dragged
+  stacks above all piles.
+- **Draw-Three waste fan hit testing on Android.** The renderer and the click
+  hit-test now share a single `waste_fan_step` / `tableau_col_step` source. They
+  previously diverged under Android's tighter column spacing, shifting the top
+  fanned waste card's hit target onto the card beneath it, so dragging the visible
+  card played the wrong one.
+- **Web runtime stability.** Fixed wasm32 runtime panics, HiDPI canvas surface
+  sizing, WebGL2 shader compatibility, and Firefox boot/render behavior.
+- **Server and data hardening.** Moved bcrypt work to `spawn_blocking`, switched
+  file paths to async I/O where needed, and validated `JWT_SECRET` at startup.
+- **CI and deployment workflow.** Fixed deploy-branch handling, Docker registry
+  secret usage, and related release automation issues.
+
+### Tests
+
+- Ran an Android AVD `Pixel_7` launch smoke for the x86_64 debug APK,
+  including install, NativeActivity launch, safe-area log validation, screenshot
+  render check, onboarding input, and crash-log review.
+- Added direct coverage for Android/touch card corner labels using Unicode suit
+  glyphs.
+- Added schema-v3 persistence round-trip coverage, foundation-to-tableau
+  instruction coverage, expanded WASM unit tests, and Playwright E2E specs for
+  browser routes and game-canvas behavior.
+
+## [0.39.0] — 2026-05-19
+
+### Fixed
+
+- **No-legal-moves detection and banner.** Corrected no-move detection across
+  engine, WASM, and web paths, then surfaced the state to players with an
+  in-game banner instead of silently leaving the board stuck.
+- **Release/deploy automation.** Updated deployment automation so kustomization
+  changes are pushed to the deploy branch instead of the main development
+  branch.
+
+## [0.38.0] — 2026-05-19
+
+### Added
+
+- **Klondike scoring parity.** Added tableau flip bonuses and stock recycle
+  penalties to align scoring with standard Klondike expectations.
+
+### Fixed
+
+- **Core rule enforcement.** Auto-complete now requires an empty waste pile,
+  waste-origin moves reject multi-card transfers, foundation-to-foundation moves
+  are blocked, and undo restores score from the snapshot baseline.
+- **Modal lifecycle guards.** Added missing `ModalScrim` guards to New Game,
+  restore prompt, and no-moves modal spawn sites.
+- **Runtime and server robustness.** Tokio runtime setup degrades gracefully
+  instead of panicking; web replay submission casing/date formatting now matches
+  server expectations; avatar routes are publicly reachable when intended.
+- **Android token and sync merge correctness.** Android tokens are namespaced
+  under the application directory, stored per user, and migrated safely; sync
+  merges preserve draw-one / draw-three win invariants.
+
+## [0.37.0] — 2026-05-19
+
+### Fixed
+
+- **Foundation-to-tableau default.** Made `take_from_foundation` default to true
+  across clients so restored, startup, and web games use the same supported move
+  rules.
+
+## [0.36.12] — 2026-05-19
+
+### Fixed
+
+- **Foundation-to-tableau default.** Set `take_from_foundation` true by default
+  in core so every client inherits the intended house rule without special-case
+  setup.
+
+## [0.36.11] — 2026-05-19
+
+### Fixed
+
+- **Web foundation moves.** Enabled take-from-foundation moves in the web game
+  client.
+
+## [0.36.10] — 2026-05-19
+
+### Added
+
+- **Web resume flow.** Browser games now persist state across page refreshes and
+  can resume through a dialog instead of starting over.
+
+## [0.36.9] — 2026-05-19
+
+### Fixed
+
+- **Settings sync connection flow.** Clicking Connect from Settings now opens the
+  sync-setup modal.
+
+## [0.36.8] — 2026-05-19
+
+### Fixed
+
+- **Restored/startup foundation moves.** Enabled take-from-foundation behavior
+  for restored and startup games, not only newly-created sessions.
+
+## [0.36.7] — 2026-05-19
+
+### Fixed
+
+- **Remaining Android UI issues.** Resolved the final Android UI defects from
+  the review pass, including action-bar/tableau interaction and safe visual
+  spacing.
+
+## [0.36.6] — 2026-05-19
+
+### Fixed
+
+- **Action-bar layout reservation.** Reserved action-bar height in layout so
+  tableau columns do not extend behind bottom controls.
+
+## [0.36.5] — 2026-05-19
+
+### Added
+
+- **Responsive Android action-bar glyphs.** Action-bar glyph font size now scales
+  dynamically on Android to fit available space.
+
+## [0.36.4] — 2026-05-19
+
+### Fixed
+
+- **Classic card labels and HUD overlap.** Corrected classic-card corner-label
+  colors and fixed HUD-band overlap in the Android layout.
+
+## [0.36.3] — 2026-05-19
+
+### Fixed
+
+- **Core, animation, and modal review fixes.** Added the foundation-to-tableau
+  score penalty, hardened solver win validation, guarded zero-duration card
+  animations, aligned initial and dynamic tableau fan spacing, and added missing
+  modal guards for play-by-seed and win-summary paths.
+- **Pause, messages, credentials, and server validation.** Auto-complete respects
+  pause state, standalone plugins register their events, sync passwords are
+  cleared from ECS buffers after auth task spawn, and avatar MIME validation uses
+  exact matches.
+- **Foundation pile rendering.** Raised stack fan z-order above corner labels to
+  prevent bleed-through.
+- **Android release workflow.** Added a manual `workflow_dispatch` trigger to
+  the Android release workflow.
+
+## [0.36.2] — 2026-05-19
+
+### Fixed
+
+- **Comprehensive review fixes.** Addressed 26 issues across core rules, replay
+  controls, modal guards, sync payload timing, server replay casing, time-attack
+  overlays, theme refresh, auth overlays, stats ordering, animations, cursor
+  fallbacks, achievements, server temp-file cleanup, and runtime fallback paths.
+- **Animation and Android label polish.** Cancelled stale win-cascade animations
+  on new game, refreshed Android corner labels on resize, lifted animating cards
+  above lower z-layers, and froze the web timer when auto-complete starts.
+- **Web package and tooling updates.** Rebuilt the WASM package for
+  foundation-to-tableau moves, added ruflo scaffolding, and ignored ruflo runtime
+  state files.
+- **Leaderboard test stability.** Made opt-in / opt-out tests robust under
+  parallel test execution.
+
+## [0.36.1] — 2026-05-18
+
+### Fixed
+
+- **Android HUD gesture conflict.** Stock taps no longer toggle HUD visibility on
+  Android.
+
+## [0.36.0] — 2026-05-18
+
+### Changed
+
+- **Rank model cleanup.** `Rank` now uses explicit discriminants and checked
+  arithmetic, making rank conversions and sequencing more robust.
+- **Instruction generation.** Refined `possible_instructions` alongside the rank
+  arithmetic cleanup.
+- **Session handoff.** Recreated `SESSION_HANDOFF.md` to reflect the `0.35.1`
+  state.
+
+## [0.35.1] — 2026-05-17
+
+### Fixed
+
+- **Leaderboard profile sync.** Fixed three leaderboard/profile issues: wrong
+  toast type for failures, stale display-name label after update, and display
+  name not syncing to the server.
+
+## [0.35.0] — 2026-05-17
+
+### Added
+
+- **Reduced-motion support.** Decorative motion animations are now gated behind
+  `reduce_motion_mode`.
+
+### Changed
+
+- **Performance and runtime cleanup.** Shared a single Tokio runtime across
+  network tasks and gated frame-hot ECS systems on resource changes.
+- **Core/data refactors.** Consolidated the application directory name, added
+  `#[must_use]` to pure helpers, derived `Copy` for `DrawMode`, removed
+  redundant clones, added missing derives to `AchievementContext`, and used
+  saturating move-count arithmetic.
+- **HUD z-layer naming.** Replaced raw HUD popover z-index arithmetic with named
+  layer constants.
+
+### Fixed
+
+- **Android UI and font safety.** Wired FiraMono to stock-empty labels, removed
+  raw physical safe-area pixels from HUD spawns, replaced unsupported chevrons,
+  corrected the Android help hint label, and fixed touch/drop-zone behavior.
+- **Engine modal and panic hardening.** Eliminated several runtime panics, added
+  required transforms to modal scrims, constrained dismiss hit-tests, and guarded
+  home overlay respawns.
+- **Sync/data/server correctness.** Deterministic pile serialization, undo skip
+  handling, byte URL encoding, merge timestamp handling, auth-guarded avatar
+  serving, atomic server writes, and user-id assertions were corrected.
+- **Display-name and token-file boundaries.** Enforced the 32-character display
+  name limit in the sync client and aligned Android keystore temp-file cleanup
+  with the cleanup glob.
+- **WASM error reporting.** `state()` and `step()` now return `Result` so errors
+  surface as JavaScript exceptions.
+- **Sync and leaderboard toasts.** Pull failures and leaderboard opt-in /
+  opt-out failures now produce the intended warning/error feedback.
+
+### Documentation
+
+- Corrected stale focus-ring color documentation.
+
+## [0.34.0] — 2026-05-17
+
+### Fixed
+
+- **Android waste fan and resume layout.** Corrected Android waste-pile fan
+  overlap and a layout desynchronization after resume.
+- **Card-face artwork.** Fixed the wrong bottom-right suit symbol on the jack,
+  queen, and king of spades.
+- **Android corner-label font coverage.** Wired FiraMono into Android corner
+  labels and added `CardImageSet` tests to guard the asset path behavior.
+
 ## [0.33.0] — 2026-05-16
 
 ### Fixed

CLAUDE.md

@@ -208,9 +208,14 @@ Embed via `include_bytes!()` only when ALL of the following are true:
 Currently embedded:
 * **Audio** — all `.wav` files in `audio_plugin.rs`
 * **Default card theme** — shipped via `embedded://` scheme in `ThemePlugin`
+* **Bundled UI font** — `assets/fonts/main.ttf` (FiraMono) via `include_bytes!`
+  in `font_plugin.rs` and `assets/svg_loader.rs`; it is the canonical UI face
+  and must always be present, so it is embedded rather than `AssetServer`-loaded
 
-Do NOT embed card face PNGs, background images, or user fonts —
+Do NOT embed card face PNGs or background images — these are loaded via
-these are loaded via `AssetServer` so art can be swapped without recompile.
+`AssetServer` so art can be swapped without recompile. User-supplied fonts
+(if ever added) likewise go through `AssetServer`; only the bundled FiraMono
+face above is embedded.
 
 ---
 
@@ -430,9 +435,11 @@ explicitly replacing the current one (despawn first, then spawn).
 
 ## 14.3 Safe area
 
-Every `ModalScrim` automatically receives `padding.bottom` equal to the
+Every `ModalScrim` automatically receives `padding.top` equal to the logical
-logical gesture-bar height via `apply_safe_area_to_modal_scrims` in
+status-bar height and `padding.bottom` equal to the logical gesture-bar height
-`SafeAreaInsetsPlugin`. Do not manually add bottom padding to scrim nodes.
+via `apply_safe_area_to_modal_scrims` in `SafeAreaInsetsPlugin`. This centres
+the modal card within the usable area between both system bars. Do not manually
+add top or bottom padding to scrim nodes.
 
 ## 14.4 Z-ordering
 

Cargo.lock

@@ -364,6 +364,12 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "arrayvec"
+version = "0.7.6"
+source = "sparse+https://git.aleshym.co/api/packages/Quaternions/cargo/"
+checksum = "813440870d646c57c222c1d713dc4e3ddcb2919c3801564d767d85d7bf2afee4"
+
 [[package]]
 name = "as-raw-xcb-connection"
 version = "1.0.1"
@@ -717,6 +723,28 @@ dependencies = [
  "android-activity",
 ]
 
+[[package]]
+name = "bevy_anti_alias"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "726cc494eb7d6a84ce6291c23636fd451fa4846604dc059fa93febca4e60a928"
+dependencies = [
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_core_pipeline",
+ "bevy_derive",
+ "bevy_diagnostic",
+ "bevy_ecs",
+ "bevy_image",
+ "bevy_math",
+ "bevy_reflect",
+ "bevy_render",
+ "bevy_shader",
+ "bevy_utils",
+ "tracing",
+]
+
 [[package]]
 name = "bevy_app"
 version = "0.18.1"
@@ -878,6 +906,35 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "bevy_dev_tools"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4f1464a3f5ef5c23d917987714ee89881f9f791e9ff97ecf6600ee846b9569e"
+dependencies = [
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_color",
+ "bevy_diagnostic",
+ "bevy_ecs",
+ "bevy_image",
+ "bevy_input",
+ "bevy_math",
+ "bevy_picking",
+ "bevy_reflect",
+ "bevy_render",
+ "bevy_shader",
+ "bevy_state",
+ "bevy_text",
+ "bevy_time",
+ "bevy_transform",
+ "bevy_ui",
+ "bevy_ui_render",
+ "bevy_window",
+ "tracing",
+]
+
 [[package]]
 name = "bevy_diagnostic"
 version = "0.18.1"
@@ -901,7 +958,7 @@ version = "0.18.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c9cf7a3ee41342dd7b5a5d82e200d0e8efb933169247fce853b4ad633d51e87d"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bevy_ecs_macros",
  "bevy_platform",
  "bevy_ptr",
@@ -945,6 +1002,36 @@ dependencies = [
  "encase_derive_impl",
 ]
 
+[[package]]
+name = "bevy_feathers"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1cb29be8f8443c5cc44e1c4710bbe02877e73703c60228ca043f20529a5496c6"
+dependencies = [
+ "accesskit",
+ "bevy_a11y",
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_color",
+ "bevy_derive",
+ "bevy_ecs",
+ "bevy_input_focus",
+ "bevy_log",
+ "bevy_math",
+ "bevy_picking",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_render",
+ "bevy_shader",
+ "bevy_text",
+ "bevy_ui",
+ "bevy_ui_render",
+ "bevy_ui_widgets",
+ "bevy_window",
+ "smol_str",
+]
+
 [[package]]
 name = "bevy_gizmos"
 version = "0.18.1"
@@ -1067,14 +1154,17 @@ checksum = "6a11df62e49897def470471551c02f13c6fb488e55dddb5ab7ef098132e07754"
 dependencies = [
  "bevy_a11y",
  "bevy_android",
+ "bevy_anti_alias",
  "bevy_app",
  "bevy_asset",
  "bevy_camera",
  "bevy_color",
  "bevy_core_pipeline",
  "bevy_derive",
+ "bevy_dev_tools",
  "bevy_diagnostic",
  "bevy_ecs",
+ "bevy_feathers",
  "bevy_gizmos_render",
  "bevy_image",
  "bevy_input",
@@ -1082,6 +1172,7 @@ dependencies = [
  "bevy_log",
  "bevy_math",
  "bevy_mesh",
+ "bevy_pbr",
  "bevy_platform",
  "bevy_ptr",
  "bevy_reflect",
@@ -1101,6 +1192,27 @@ dependencies = [
  "bevy_winit",
 ]
 
+[[package]]
+name = "bevy_light"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4d9d2ac64390a9baacb3c0fa0f5456ac1553959d5a387874c102a09aab8b92cc"
+dependencies = [
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_color",
+ "bevy_ecs",
+ "bevy_image",
+ "bevy_math",
+ "bevy_mesh",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_transform",
+ "bevy_utils",
+ "tracing",
+]
+
 [[package]]
 name = "bevy_log"
 version = "0.18.1"
@@ -1138,7 +1250,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e931fa969f89c83498b22c97432383afe90e90fd1a5e04fa07be8da4d3bcac84"
 dependencies = [
  "approx",
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bevy_reflect",
  "derive_more",
  "glam 0.30.10",
@@ -1161,7 +1273,9 @@ dependencies = [
  "bevy_asset",
  "bevy_derive",
  "bevy_ecs",
+ "bevy_image",
  "bevy_math",
+ "bevy_mikktspace",
  "bevy_platform",
  "bevy_reflect",
  "bevy_transform",
@@ -1174,6 +1288,71 @@ dependencies = [
  "wgpu-types",
 ]
 
+[[package]]
+name = "bevy_mikktspace"
+version = "0.17.0-dev"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ef8e4b7e61dfe7719bb03c884dc270cd46a82efb40f93e9933b990c5c190c59"
+
+[[package]]
+name = "bevy_pbr"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a5ab6944ffc6fd71604c0fbca68cc3e2a3654edfcdbfd232f9d8b88e3d20fdc0"
+dependencies = [
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_color",
+ "bevy_core_pipeline",
+ "bevy_derive",
+ "bevy_diagnostic",
+ "bevy_ecs",
+ "bevy_image",
+ "bevy_light",
+ "bevy_log",
+ "bevy_math",
+ "bevy_mesh",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_render",
+ "bevy_shader",
+ "bevy_transform",
+ "bevy_utils",
+ "bitflags 2.11.1",
+ "bytemuck",
+ "derive_more",
+ "fixedbitset",
+ "nonmax",
+ "offset-allocator",
+ "smallvec",
+ "static_assertions",
+ "thiserror 2.0.18",
+ "tracing",
+]
+
+[[package]]
+name = "bevy_picking"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b7d524dbc8f2c9e73f7ab70c148c8f7886f3c24b8aa8c252a38ba68ed06cbf10"
+dependencies = [
+ "bevy_app",
+ "bevy_asset",
+ "bevy_camera",
+ "bevy_derive",
+ "bevy_ecs",
+ "bevy_input",
+ "bevy_math",
+ "bevy_platform",
+ "bevy_reflect",
+ "bevy_time",
+ "bevy_transform",
+ "bevy_window",
+ "tracing",
+ "uuid",
+]
+
 [[package]]
 name = "bevy_platform"
 version = "0.18.1"
@@ -1500,6 +1679,7 @@ dependencies = [
  "bevy_input",
  "bevy_input_focus",
  "bevy_math",
+ "bevy_picking",
  "bevy_platform",
  "bevy_reflect",
  "bevy_sprite",
@@ -1512,6 +1692,7 @@ dependencies = [
  "taffy",
  "thiserror 2.0.18",
  "tracing",
+ "uuid",
 ]
 
 [[package]]
@@ -1545,6 +1726,26 @@ dependencies = [
  "tracing",
 ]
 
+[[package]]
+name = "bevy_ui_widgets"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b6a63cb818b0de41bdb14990e0ce1aaaa347f871750ab280f80c427e83d72712"
+dependencies = [
+ "accesskit",
+ "bevy_a11y",
+ "bevy_app",
+ "bevy_camera",
+ "bevy_ecs",
+ "bevy_input",
+ "bevy_input_focus",
+ "bevy_log",
+ "bevy_math",
+ "bevy_picking",
+ "bevy_reflect",
+ "bevy_ui",
+]
+
 [[package]]
 name = "bevy_utils"
 version = "0.18.1"
@@ -1672,6 +1873,7 @@ version = "2.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c4512299f36f043ab09a583e57bceb5a5aab7a73db1805848e8fef3c9e8c78b3"
 dependencies = [
+ "bytemuck",
  "serde_core",
 ]
 
@@ -1703,7 +1905,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0aa83c34e62843d924f905e0f5c866eb1dd6545fc4d719e803d9ba6030371fce"
 dependencies = [
  "arrayref",
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "cc",
  "cfg-if",
  "constant_time_eq",
@@ -1879,6 +2081,17 @@ dependencies = [
  "wayland-client",
 ]
 
+[[package]]
+name = "card_game"
+version = "0.4.1"
+source = "sparse+https://git.aleshym.co/api/packages/Quaternions/cargo/"
+checksum = "983728ead19f51d96931725706e62293bd133ac3d836097dd7d745e929f7811b"
+dependencies = [
+ "arrayvec 0.7.6 (sparse+https://git.aleshym.co/api/packages/Quaternions/cargo/)",
+ "serde",
+ "serde_derive",
+]
+
 [[package]]
 name = "cbc"
 version = "0.1.2"
@@ -1939,6 +2152,17 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "18758054972164c3264f7c8386f5fc6da6114cb46b619fd365d4e3b2dc3ae487"
 
+[[package]]
+name = "chacha20"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6f8d983286843e49675a4b7a2d174efe136dc93a18d69130dd18198a6c167601"
+dependencies = [
+ "cfg-if",
+ "cpufeatures 0.3.0",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "chrono"
 version = "0.4.44"
@@ -3457,6 +3681,17 @@ dependencies = [
  "weezl",
 ]
 
+[[package]]
+name = "gl_generator"
+version = "0.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a95dfc23a2b4a9a2f5ab41d194f8bfda3cabec42af4e39f08c339eb2a0c124d"
+dependencies = [
+ "khronos_api",
+ "log",
+ "xml-rs",
+]
+
 [[package]]
 name = "glam"
 version = "0.30.10"
@@ -3485,6 +3720,27 @@ version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0cc23270f6e1808e30a928bdc84dea0b9b4136a8bc82338574f23baf47bbd280"
 
+[[package]]
+name = "glow"
+version = "0.16.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c5e5ea60d70410161c8bf5da3fdfeaa1c72ed2c15f8bbb9d19fe3a4fad085f08"
+dependencies = [
+ "js-sys",
+ "slotmap",
+ "wasm-bindgen",
+ "web-sys",
+]
+
+[[package]]
+name = "glutin_wgl_sys"
+version = "0.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c4ee00b289aba7a9e5306d57c2d05499b2e5dc427f84ac708bd2c090212cf3e"
+dependencies = [
+ "gl_generator",
+]
+
 [[package]]
 name = "governor"
 version = "0.10.4"
@@ -4051,7 +4307,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "525e9ff3e1a4be2fbea1fdf0e98686a6d98b4d8f937e1bf7402245af1909e8c3"
 dependencies = [
  "byteorder-lite",
- "quick-error",
+ "quick-error 2.0.1",
 ]
 
 [[package]]
@@ -4309,6 +4565,23 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "khronos-egl"
+version = "6.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6aae1df220ece3c0ada96b8153459b67eebe9ae9212258bb0134ae60416fdf76"
+dependencies = [
+ "libc",
+ "libloading",
+ "pkg-config",
+]
+
+[[package]]
+name = "khronos_api"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2db585e1d738fc771bf08a151420d3ed193d9d895a36df7f6f8a9456b911ddc"
+
 [[package]]
 name = "kira"
 version = "0.12.0"
@@ -4326,13 +4599,25 @@ dependencies = [
  "triple_buffer",
 ]
 
+[[package]]
+name = "klondike"
+version = "0.4.0"
+source = "sparse+https://git.aleshym.co/api/packages/Quaternions/cargo/"
+checksum = "d5c82b0c3abd7da07b4a1c4221a809e6e2ffd475ae0e67180fbfef35a9cfe769"
+dependencies = [
+ "card_game",
+ "rand 0.10.1",
+ "serde",
+ "serde_derive",
+]
+
 [[package]]
 name = "kurbo"
 version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7564e90fe3c0d5771e1f0bc95322b21baaeaa0d9213fa6a0b61c99f8b17b3bfb"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "euclid",
  "smallvec",
 ]
@@ -4740,7 +5025,7 @@ version = "27.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "066cf25f0e8b11ee0df221219010f213ad429855f57c494f995590c861a9a7d8"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bit-set",
  "bitflags 2.11.1",
  "cfg-if",
@@ -5778,6 +6063,25 @@ version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3eb8486b569e12e2c32ad3e204dbaba5e4b5b216e9367044f25f1dba42341773"
 
+[[package]]
+name = "proptest"
+version = "1.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4b45fcc2344c680f5025fe57779faef368840d0bd1f42f216291f0dc4ace4744"
+dependencies = [
+ "bit-set",
+ "bit-vec",
+ "bitflags 2.11.1",
+ "num-traits",
+ "rand 0.9.4",
+ "rand_chacha 0.9.0",
+ "rand_xorshift",
+ "regex-syntax",
+ "rusty-fork",
+ "tempfile",
+ "unarray",
+]
+
 [[package]]
 name = "prost"
 version = "0.14.3"
@@ -5822,6 +6126,12 @@ dependencies = [
  "winapi",
 ]
 
+[[package]]
+name = "quick-error"
+version = "1.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1d01941d82fa2ab50be1e79e6714289dd7cde78eba4c074bc5a4374f650dfe0"
+
 [[package]]
 name = "quick-error"
 version = "2.0.1"
@@ -5947,6 +6257,16 @@ dependencies = [
  "rand_core 0.9.5",
 ]
 
+[[package]]
+name = "rand"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2e8e8bcc7961af1fdac401278c6a831614941f6164ee3bf4ce61b7edb162207"
+dependencies = [
+ "chacha20",
+ "rand_core 0.10.1",
+]
+
 [[package]]
 name = "rand_chacha"
 version = "0.3.1"
@@ -5985,6 +6305,12 @@ dependencies = [
  "getrandom 0.3.4",
 ]
 
+[[package]]
+name = "rand_core"
+version = "0.10.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "63b8176103e19a2643978565ca18b50549f6101881c443590420e4dc998a3c69"
+
 [[package]]
 name = "rand_distr"
 version = "0.5.1"
@@ -6004,6 +6330,15 @@ dependencies = [
  "rand_core 0.6.4",
 ]
 
+[[package]]
+name = "rand_xorshift"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "513962919efc330f829edb2535844d1b912b0fbe2ca165d613e4e8788bb05a5a"
+dependencies = [
+ "rand_core 0.9.5",
+]
+
 [[package]]
 name = "range-alloc"
 version = "0.1.5"
@@ -6493,6 +6828,18 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
 
+[[package]]
+name = "rusty-fork"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cc6bf79ff24e648f6da1f8d1f011e9cac26491b619e6b9280f2b47f1774e6ee2"
+dependencies = [
+ "fnv",
+ "quick-error 1.2.3",
+ "tempfile",
+ "wait-timeout",
+]
+
 [[package]]
 name = "rustybuzz"
 version = "0.20.1"
@@ -6959,6 +7306,7 @@ name = "solitaire_app"
 version = "0.1.0"
 dependencies = [
  "bevy",
+ "jni 0.21.1",
  "keyring",
  "solitaire_data",
  "solitaire_engine",
@@ -6980,7 +7328,9 @@ dependencies = [
 name = "solitaire_core"
 version = "0.1.0"
 dependencies = [
- "rand 0.9.4",
+ "card_game",
+ "klondike",
+ "proptest",
  "serde",
  "thiserror 2.0.18",
 ]
@@ -6991,12 +7341,13 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "axum",
- "bevy",
+ "card_game",
  "chrono",
  "dirs",
  "jni 0.21.1",
  "jsonwebtoken",
  "keyring-core",
+ "klondike",
  "reqwest",
  "serde",
  "serde_json",
@@ -7090,6 +7441,18 @@ dependencies = [
  "web-sys",
 ]
 
+[[package]]
+name = "solitaire_web"
+version = "0.1.0"
+dependencies = [
+ "bevy",
+ "console_error_panic_hook",
+ "getrandom 0.3.4",
+ "solitaire_data",
+ "solitaire_engine",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "spin"
 version = "0.9.8"
@@ -7502,7 +7865,7 @@ version = "0.5.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ea00cc4f79b7f6bb7ff87eddc065a1066f3a43fe1875979056672c9ef948c2af"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 1.3.2",
  "bytemuck",
  "lazy_static",
@@ -7601,7 +7964,7 @@ version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "41ba83ebaf2954d31d05d67340fd46cebe99da2b7133b0dd68d70c65473a437b"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "grid",
  "serde",
  "slotmap",
@@ -7870,7 +8233,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "83d13394d44dae3207b52a326c0c85a8bf87f1541f23b0d143811088497b09ab"
 dependencies = [
  "arrayref",
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bytemuck",
  "cfg-if",
  "log",
@@ -7884,7 +8247,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "47ffee5eaaf5527f630fb0e356b90ebdec84d5d18d937c5e440350f88c5a91ea"
 dependencies = [
  "arrayref",
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bytemuck",
  "cfg-if",
  "log",
@@ -8533,6 +8896,12 @@ dependencies = [
  "windows-sys 0.61.2",
 ]
 
+[[package]]
+name = "unarray"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eaea85b334db583fe3274d12b4cd1880032beab409c0d774be044d4480ab9a94"
+
 [[package]]
 name = "uncased"
 version = "0.9.10"
@@ -8739,6 +9108,15 @@ version = "0.9.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0b928f33d975fc6ad9f86c8f283853ad26bdd5b10b7f1542aa2fa15e2289105a"
 
+[[package]]
+name = "wait-timeout"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "09ac3b126d3914f9849036f826e054cbabdc8519970b8998ddaf3b5bd3c65f11"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "walkdir"
 version = "2.5.0"
@@ -9044,12 +9422,13 @@ version = "27.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bfe68bac7cde125de7a731c3400723cadaaf1703795ad3f4805f187459cd7a77"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bitflags 2.11.1",
  "cfg-if",
  "cfg_aliases",
  "document-features",
  "hashbrown 0.16.1",
+ "js-sys",
  "log",
  "naga",
  "portable-atomic",
@@ -9057,6 +9436,8 @@ dependencies = [
  "raw-window-handle",
  "smallvec",
  "static_assertions",
+ "wasm-bindgen",
+ "web-sys",
  "wgpu-core",
  "wgpu-hal",
  "wgpu-types",
@@ -9068,7 +9449,7 @@ version = "27.0.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "27a75de515543b1897b26119f93731b385a19aea165a1ec5f0e3acecc229cae7"
 dependencies = [
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "bit-set",
  "bit-vec",
  "bitflags 2.11.1",
@@ -9088,6 +9469,7 @@ dependencies = [
  "smallvec",
  "thiserror 2.0.18",
  "wgpu-core-deps-apple",
+ "wgpu-core-deps-wasm",
  "wgpu-core-deps-windows-linux-android",
  "wgpu-hal",
  "wgpu-types",
@@ -9102,6 +9484,15 @@ dependencies = [
  "wgpu-hal",
 ]
 
+[[package]]
+name = "wgpu-core-deps-wasm"
+version = "27.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b1027dcf3b027a877e44819df7ceb0e2e98578830f8cd34cd6c3c7c2a7a50b7"
+dependencies = [
+ "wgpu-hal",
+]
+
 [[package]]
 name = "wgpu-core-deps-windows-linux-android"
 version = "27.0.0"
@@ -9118,7 +9509,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5b21cb61c57ee198bc4aff71aeadff4cbb80b927beb912506af9c780d64313ce"
 dependencies = [
  "android_system_properties",
- "arrayvec",
+ "arrayvec 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "ash",
  "bit-set",
  "bitflags 2.11.1",
@@ -9127,15 +9518,20 @@ dependencies = [
  "cfg-if",
  "cfg_aliases",
  "core-graphics-types 0.2.0",
+ "glow",
+ "glutin_wgl_sys",
  "gpu-alloc",
  "gpu-allocator",
  "gpu-descriptor",
  "hashbrown 0.16.1",
+ "js-sys",
+ "khronos-egl",
  "libc",
  "libloading",
  "log",
  "metal",
  "naga",
+ "ndk-sys",
  "objc",
  "once_cell",
  "ordered-float",
@@ -9148,6 +9544,8 @@ dependencies = [
  "renderdoc-sys",
  "smallvec",
  "thiserror 2.0.18",
+ "wasm-bindgen",
+ "web-sys",
  "wgpu-types",
  "windows 0.58.0",
  "windows-core 0.58.0",
@@ -10030,6 +10428,12 @@ version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9cc00251562a284751c9973bace760d86c0276c471b4be569fe6b068ee97a56"
 
+[[package]]
+name = "xml-rs"
+version = "0.8.28"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ae8337f8a065cfc972643663ea4279e04e7256de865aa66fe25cec5fb912d3f"
+
 [[package]]
 name = "xmlwriter"
 version = "0.1.0"

Cargo.toml

@@ -8,6 +8,7 @@ members = [
     "solitaire_app",
     "solitaire_assetgen",
     "solitaire_wasm",
+    "solitaire_web",
 ]
 resolver = "2"
 
@@ -17,11 +18,27 @@ version = "0.1.0"
 license = "MIT"
 rust-version = "1.95"
 
+# Pedantic correctness lints applied across every member crate via
+# `[lints] workspace = true`.
+[workspace.lints.rust]
+# Workspace-wide ban on `unsafe`. The sole exception is `solitaire_app`,
+# which sets its own `deny`-level lints (see its Cargo.toml) because the
+# Android cdylib entry point must reconstruct raw JNI handles. Every other
+# crate reaches Android JNI through the safe `solitaire_data::android_jni`
+# bridge and stays fully unsafe-free.
+unsafe_code = "forbid"
+single_use_lifetimes = "warn"
+trivial_casts = "warn"
+unused_lifetimes = "warn"
+unused_qualifications = "warn"
+variant_size_differences = "warn"
+unexpected_cfgs = "warn"
+
 [workspace.dependencies]
 serde       = { version = "1", features = ["derive"] }
 serde_json  = "1"
 uuid        = { version = "1", features = ["v4", "serde"] }
-chrono      = { version = "0.4", features = ["serde"] }
+chrono      = { version = "0.4", features = ["serde", "wasmbind"] }
 thiserror   = "2"
 rand        = "0.9"
 async-trait = "0.1"
@@ -37,6 +54,8 @@ solitaire_core   = { path = "solitaire_core" }
 solitaire_sync   = { path = "solitaire_sync" }
 solitaire_data   = { path = "solitaire_data" }
 solitaire_engine = { path = "solitaire_engine" }
+klondike         = { version = "0.4.0", registry = "Quaternions", features = ["serde"] }
+card_game        = { version = "0.4.1", registry = "Quaternions", features = ["serde"] }
 
 # Bevy with `default-features = false` to avoid the unused
 # `bevy_audio → rodio + symphonia + cpal 0.15 + alsa 0.9` chain.

README.md

@@ -118,8 +118,28 @@ cargo test -p solitaire_core -p solitaire_sync -p solitaire_data -p solitaire_se
 
 # Lint
 cargo clippy --workspace --all-targets -- -D warnings
+
+# Browser e2e smoke (starts solitaire_server automatically)
+cd solitaire_server/e2e
+npm ci
+npx playwright install chromium
+npm test
+
+# Seed-batch cycle regression gate (thresholded)
+npm run review:cycles:regression
+
+# Loop-aware candidate benchmark (writes test-results/cycle-candidate.json)
+npm run review:cycles:candidate
 ```
 
+For layered engine-vs-UI automation design (Rust unit tests, wasm debug-API
+integration tests, and Playwright UI validation), see
+[docs/testing-architecture.md](docs/testing-architecture.md).
+
+For Quaternions (`klondike` / `card_game`) dependency upgrades, use
+[`scripts/update_quaternions_deps.sh`](scripts/update_quaternions_deps.sh) and
+the runbook in [docs/card-game-integration.md](docs/card-game-integration.md).
+
 ## Credits
 
 Built on [Bevy](https://bevyengine.org/) and the wider Rust ecosystem

SESSION_HANDOFF.md

@@ -1,16 +1,62 @@
 # Ferrous Solitaire — Session Handoff
 
-**Last updated:** 2026-05-18 — Three leaderboard bugs fixed, tagged v0.35.1. All commits on origin/master.
+**Last updated:** 2026-06-25 — v0.40.0 released (Android APK published); physical-device gate remains.
 
 ---
 
 ## Current state
 
-- **HEAD on origin/master:** `8f86d66` (fix: three leaderboard bugs)
+- **Branch state:** `master` pushed to origin; latest commits are the Draw-Three waste fan fix, its regression tests, and the NDK doc update (PRs #105–#108).
-- **Latest tag:** `v0.35.1`
+- **Latest tag:** `v0.40.0` (released — signed arm64-v8a APK published to the Gitea release for Obtainium/sideload). `v0.39.1` was the prior published release.
-- **Working tree:** clean
+- **Working tree:** clean. Local `scripts/` helpers (incl. `scripts/watch_deploy.sh`) are intentionally not committed.
-- **Build:** `cargo clippy --workspace -- -D warnings` clean
+- **Latest verification this session:** `cargo clippy --workspace --all-targets -- -D warnings`; `cargo test --workspace`; `cargo build -p solitaire_app`; Android cross-compile + clippy for `aarch64-linux-android` (clean); full local signed arm64-v8a APK via `scripts/build_android_apk.sh`; CI `android-release` for `v0.40.0` completed/success with APK download HTTP 200.
-- **Tests:** 1277 passing / 0 failing across the workspace
+- **Full previous gate:** card_game work pushed to origin with `cargo test` / `clippy` gates passing.
+
+---
+
+## v0.40.0 release (2026-06-25)
+
+Released via tag push → `.gitea/workflows/android-release.yml` built and signed the
+arm64-v8a release APK (release keystore, `versionCode 4000` / `versionName 0.40.0`,
+29.2 MB) and published it to the Gitea release. Obtainium clients tracking the repo
+pick it up automatically.
+
+- Release: https://git.aleshym.co/funman300/Ferrous-Solitaire/releases/tag/v0.40.0
+
+| PR | Summary |
+|----|---------|
+| #106 | **fix(engine):** Draw-Three waste fan hit-test now shares the renderer's fan step (`card_plugin::waste_fan_step` / `tableau_col_step`). The two had diverged under Android's tighter column spacing (`H_GAP_DIVISOR=32`), shifting the top fanned waste card's click target onto the card beneath it — so dragging the visible top card played the wrong one. Desktop/web were unaffected (the formulas already coincided there). |
+| #105 | **test(engine):** waste-card draggability regression tests (`find_draggable_at` picks the waste top with multiple cards and as a lone card). |
+| #108 | **docs(android):** NDK reference updated `26.3.11579264` → `30.0.14904198`; noted versions are not load-bearing and `build_android_apk.sh` auto-discovers the newest NDK/build-tools. |
+
+Pre-release validation performed locally this session: workspace clippy/test/build
+gates; `aarch64-linux-android` cross-compile + clippy clean (covers the
+`#[cfg(target_os = "android")]` paths that host CI never lints); release manifest
+sanity (`solitaire_app/android/AndroidManifest.xml` has no version fields so CI
+injection works; `lib_name` matches `[lib].name`); and a full signed local APK
+proving the `build_android_apk.sh` packaging pipeline end-to-end.
+
+---
+
+## What shipped since v0.39.0
+
+- Browser Bevy canvas route and `window.__FERROUS_DEBUG__` automation bridge landed, with Playwright coverage for `/play`.
+- In-place `card_game` / `klondike` rewrite phases are complete through the latest follow-up:
+  - `5e87358` integrates upstream deps cleanly.
+  - `ae1ecc8` unifies `Suit` / `Rank` with upstream `card_game` types.
+  - `d864d98` routes klondike/card imports through `solitaire_core`.
+  - `9bcf13d`, `56e3b62`, `26f1b00` finish schema-v3 migration coverage, undo/recycle score correctness, and rewrite-plan docs.
+- Android keystore wiring, Android build-script hardening, server auth/runtime hardening, and modal safe-area centering have landed.
+- `CHANGELOG.md` has been caught up from `v0.34.0` through current unreleased work and committed in `7fe6ac6`.
+- Matomo analytics was re-reviewed: `MatomoClient` and `AnalyticsPlugin` are wired through `CoreGamePlugin` on non-wasm targets, and targeted tests now cover opt-in client creation, event encoding, buffer trimming, and analytics mode labels.
+- Native analytics and Android physical-device validation now have runbooks in
+  `docs/analytics-validation.md` and `docs/ANDROID.md`.
+
+---
+
+## Historical notes before v0.39.0
+
+See git log and `CHANGELOG.md`. The changelog now includes `v0.34.0` through `v0.39.0`, plus current unreleased work.
 
 ---
 
@@ -81,32 +127,38 @@ Three bugs fixed:
 
 ## Open punch list
 
-### 1. CHANGELOG documentation debt
+### 1. Physical-device smoke test — THE ONLY REMAINING v0.40.0 ITEM
 
-CHANGELOG.md currently ends at v0.33.0. Entries for v0.34.0, v0.35.0, and v0.35.1
+This is the **single outstanding task** for the v0.40.0 Android release. Everything
-are missing. Low priority (git log is authoritative) but worth closing before the
+else is done and verified: workspace gates, `aarch64-linux-android` cross-compile +
-next release.
+clippy, release manifest sanity, a full local signed APK, the published release, and
+Obtainium-facing delivery (public releases API, latest non-draft release, APK
+downloadable anonymously). The only thing that cannot be done without hardware is
+running the app on a real phone.
 
-### 2. Android APK launch verification (Option A)
+Install the published APK on a real Android device (not AVD) and run the checklist
+in `docs/ANDROID.md §4`. This has never been gated in CI — AVD `adb shell input tap`
+doesn't deliver real touch events, so physical-device smoke testing is the only gate.
 
-Physical device test: install the latest APK on a real Android device (not AVD),
+The signed release APK is published (grab it from the release page, or use the local
-confirm:
+`target/debug/apk/ferrous-solitaire.apk`). When testing, specifically exercise the
-- App launches without crash
+Draw-Three waste fan fixed in #106: switch to Draw-Three, draw several cards, and
-- Safe area insets arrive and shift HUD correctly after ~3 frames
+confirm dragging the visible top waste card plays *that* card, not the one beneath it.
-- All modal Done buttons are above the gesture bar
-- Drag-and-drop works on all pile types
-- Leaderboard panel opens and the "Public name" label updates correctly after
-  using "Set Name"
 
-This has never been gated in CI. AVD `adb shell input tap` doesn't deliver real
+Latest AVD smoke (2026-06-08 local / 2026-06-09 UTC): built
-touch events, so physical-device smoke testing is the only gate.
+`target/debug/apk/ferrous-solitaire.apk` for `x86_64-linux-android`, installed
+it on AVD `Pixel_7`, launched `android.app.NativeActivity`, confirmed Bevy
+rendered the board, safe-area insets resolved as `top=136 bottom=63 left=0
+right=0` after 2 frames, onboarding could be dismissed via AVD input, and
+filtered logcat showed no Ferrous panic/fatal/ANR.
 
-### 3. Matomo analytics wiring
+### 2. Matomo analytics live validation (independent — NOT a v0.40.0 release blocker)
 
-`Settings` has `analytics_enabled: bool` and `matomo_url: Option<String>` but no
+Separate, ongoing task unrelated to the Android release. `Settings` has
-engine code consumes them — the analytics toggle in Settings is a no-op. If
+`analytics_enabled`, `matomo_url`, and `matomo_site_id`; the engine consumes them via
-analytics are ever needed, the Matomo HTTP Tracking API client needs to be written
+`AnalyticsPlugin` on non-wasm targets. Remaining work is live validation against the
-and wired to `GameStateResource` events.
+deployed Matomo instance. Use `docs/analytics-validation.md` for the native
+validation checklist and the current web/WASM decision notes.
 
 ---
 
@@ -128,3 +180,18 @@ and wired to `GameStateResource` events.
 - **Test input-state pitfall:** `MinimalPlugins` has no input-tick system, so
   `ButtonInput::just_pressed` state persists across frames unless explicitly cleared
   with `input.release(key); input.clear()` between updates.
+
+- **`/play` debug bridge design:** `play.html` runs two independent WASM instances in
+  `Promise.all([bootstrap(), init()])`. `bootstrap()` sets `window.__FERROUS_DEBUG__`
+  (logic layer via `solitaire_wasm.js`); `init()` starts the Bevy canvas. The bridge
+  operates its own `SolitaireGame` — moves applied through the bridge do NOT affect
+  the Bevy visual game. This is intentional for automation/invariant checking.
+
+- **HiDPI Bevy canvas:** `WindowResolution::default().with_scale_factor_override(1.0)`
+  is set in the canvas app. Without this, physical pixels exceed WebGL2's 2048px limit
+  on HiDPI displays, causing an immediate wgpu panic on the first resize event.
+
+- **`/play-classic` vs `/play` in e2e:** `smoke.spec.js` + `gameplay_review.spec.js`
+  target `/play-classic` (DOM-heavy game.html); `play_canvas.spec.js` targets `/play`
+  using only the `__FERROUS_DEBUG__` bridge (no DOM selectors). `cycle_metrics.js`
+  supports both via `--route play-classic|play`.

build_wasm.sh

@@ -1,24 +1,43 @@
 #!/usr/bin/env bash
-# Rebuild the solitaire_wasm crate and install the output into
+# Rebuild WASM artifacts and install them into solitaire_server/web/pkg/.
-# solitaire_server/web/pkg/ so the server can serve the replay viewer.
+#
+# Two artifacts are produced:
+#   solitaire_wasm.*  — thin replay-viewer + interactive JS API (wasm-pack)
+#   canvas.*          — full Bevy WASM app for play.html (cargo + wasm-bindgen)
 #
 # Prerequisites:
-#   cargo install wasm-pack
+#   cargo install wasm-pack wasm-bindgen-cli
 #   rustup target add wasm32-unknown-unknown
+#   (optional) cargo install wasm-opt   # for smaller canvas_bg.wasm
 #
 # Run from the repo root:
 #   ./build_wasm.sh
 #
-# The generated files (solitaire_wasm.js + solitaire_wasm_bg.wasm) are
+# The generated pkg/ files are committed to git so self-hosters who don't
-# committed to git so self-hosters who don't touch the WASM crate can
+# touch the WASM crates can skip this step.  Regenerate after any change to
-# skip this step.  Regenerate after any change to solitaire_wasm/ or
+# solitaire_wasm/, solitaire_web/, solitaire_engine/, or solitaire_core/.
-# solitaire_core/.
 
 set -euo pipefail
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 OUT_DIR="$REPO_ROOT/solitaire_server/web/pkg"
 
+# Reproducible builds. The wasm artifacts otherwise bake in machine-specific
+# absolute source paths (the cargo registry, the rustup std sources, and this
+# checkout), so a rebuild on a different machine produces different bytes and
+# the CI freshness gate (rebuild-and-diff) false-positives. Remap all three
+# prefixes to fixed names so the output is byte-identical anywhere.
+#
+# We must use CARGO_ENCODED_RUSTFLAGS (not RUSTFLAGS) and re-state the
+# getrandom backend cfg here: a `*_RUSTFLAGS` env var *replaces* — does not
+# merge with — the `[target.wasm32-unknown-unknown] rustflags` in
+# .cargo/config.toml, so dropping that cfg would break the wasm getrandom build.
+# Keep this `--cfg` in sync with .cargo/config.toml.
+CARGO_HOME_DIR="${CARGO_HOME:-$HOME/.cargo}"
+RUSTUP_HOME_DIR="${RUSTUP_HOME:-$HOME/.rustup}"
+US=$'\x1f'   # unit separator: CARGO_ENCODED_RUSTFLAGS arg delimiter
+export CARGO_ENCODED_RUSTFLAGS="--cfg${US}getrandom_backend=\"wasm_js\"${US}--remap-path-prefix=${CARGO_HOME_DIR}=/cargo${US}--remap-path-prefix=${RUSTUP_HOME_DIR}=/rustup${US}--remap-path-prefix=${REPO_ROOT}=/build"
+
 if ! command -v wasm-pack &> /dev/null; then
     echo "error: wasm-pack not found." >&2
     echo "  Install with: cargo install wasm-pack" >&2
@@ -36,5 +55,43 @@ wasm-pack build \
 # Remove them — we manage the output directory ourselves.
 rm -f "$OUT_DIR/package.json" "$OUT_DIR/.gitignore"
 
+# ---------------------------------------------------------------------------
+# Bevy WASM app (solitaire_web → canvas.js + canvas_bg.wasm)
+# ---------------------------------------------------------------------------
+
+if ! command -v wasm-bindgen &> /dev/null; then
+    echo "error: wasm-bindgen not found." >&2
+    echo "  Install with: cargo install wasm-bindgen-cli" >&2
+    echo "  The CLI version must match the wasm-bindgen crate dep." >&2
+    exit 1
+fi
+
+echo "Building solitaire_web (Bevy WASM app)..."
+cargo build --release --target wasm32-unknown-unknown -p solitaire_web
+
+echo "Running wasm-bindgen for solitaire_web..."
+wasm-bindgen \
+    --out-dir "$OUT_DIR" \
+    --out-name canvas \
+    --target web \
+    --no-typescript \
+    "$REPO_ROOT/target/wasm32-unknown-unknown/release/solitaire_web.wasm"
+
+# Optional size optimisation — Bevy bundles are large (~5-15 MB uncompressed).
+# wasm-opt passes are skipped silently when the tool is not installed.
+if command -v wasm-opt &> /dev/null; then
+    echo "Running wasm-opt on canvas_bg.wasm..."
+    # Use -O2 (not -Oz): Bevy's render pipeline uses deep call stacks and
+    # complex memory patterns that wasm-opt -Oz can miscompile, resulting
+    # in a grey screen on first load. -O2 is speed-optimised and avoids
+    # the size-focused transforms that trigger the regression.
+    wasm-opt -O2 \
+        -o "$OUT_DIR/canvas_bg.wasm" \
+        "$OUT_DIR/canvas_bg.wasm"
+else
+    echo "note: wasm-opt not found; skipping size optimisation."
+    echo "  Install with: cargo install wasm-opt  (or via binaryen)"
+fi
+
 echo "Done. Output:"
 ls -lh "$OUT_DIR"

docs/ANDROID.md

@@ -2,13 +2,13 @@
 
 This doc captures the toolchain install + build invocation for the
 Android target. Steps are runnable on a fresh Debian 13 (trixie) box;
-later sections document what's known to compile, what's stubbed, and
+later sections document physical-device validation, supported platform
-the next milestones.
+surfaces, and remaining Android follow-ups.
 
-> **Status (2026-05-07):** First working APK at `fb8b2ac`. 54 MB
+> **Status (2026-06-09):** Android build plumbing, app-directory storage,
-> debug-signed `ferrous-solitaire.apk` for `x86_64-linux-android`. Has
+> JNI keystore wiring, and safe-area layout fixes have landed. The remaining
-> NOT yet been verified to launch on a device or emulator — that's
+> release gate is a physical-device smoke test; AVD tap injection does not
-> the next milestone.
+> exercise the real touch path reliably enough for launch verification.
 
 ---
 
@@ -35,7 +35,7 @@ rm /tmp/cmdline-tools.zip
   echo ''
   echo '# Android dev'
   echo 'export ANDROID_HOME="$HOME/Android/Sdk"'
-  echo 'export ANDROID_NDK_HOME="$ANDROID_HOME/ndk/26.3.11579264"'
+  echo 'export ANDROID_NDK_HOME="$ANDROID_HOME/ndk/30.0.14904198"'
   echo 'export JAVA_HOME="$(dirname $(dirname $(readlink -f $(which java))))"'
   echo 'export PATH="$PATH:$ANDROID_HOME/cmdline-tools/latest/bin:$ANDROID_HOME/platform-tools:$ANDROID_HOME/emulator"'
 } >> ~/.bashrc
@@ -49,10 +49,15 @@ sdkmanager \
   "platform-tools" \
   "platforms;android-34" \
   "build-tools;34.0.0" \
-  "ndk;26.3.11579264" \
+  "ndk;30.0.14904198" \
   "emulator" \
   "system-images;android-34;google_apis;x86_64"
 
+# The exact NDK/build-tools versions above are not load-bearing — newer ones
+# work (verified on NDK 30.0.14904198 / build-tools 37.0.0). `scripts/build_android_apk.sh`
+# auto-discovers the newest installed NDK and build-tools, so set ANDROID_NDK_HOME
+# (step 3) to whatever version you actually install here.
+
 # 6. AVD for testing (one-time).
 echo no | avdmanager create avd \
   -n bevy_test \
@@ -164,7 +169,7 @@ Physical device:
 
 ```bash
 adb devices                                      # confirm connection
-adb install target/debug/apk/ferrous-solitaire.apk
+adb install -r target/debug/apk/ferrous-solitaire.apk
 adb shell am start -n com.ferrousapp.solitaire/android.app.NativeActivity
 adb logcat | grep -iE "RustStdoutStderr|solitaire|panic"
 ```
@@ -185,35 +190,65 @@ AVD.
 
 ---
 
-## 4. What's wired vs. what's stubbed
+## 4. Physical-device smoke test
 
-The first build pass (commit `fb8b2ac`) gates four desktop-only
+Run this on a real phone, preferably a modern 64-bit ARM device with gesture
-crates / call sites so the workspace cross-compiles. Each gate is
+navigation enabled.
-documented at its call site.
+
+Build and install:
+
+```bash
+cargo apk build -p solitaire_app --target aarch64-linux-android --lib
+adb install -r target/debug/apk/ferrous-solitaire.apk
+adb logcat -c
+adb shell am start -n com.ferrousapp.solitaire/android.app.NativeActivity
+adb logcat | grep -iE "RustStdoutStderr|solitaire|panic|WindowInsets"
+```
+
+Pass criteria:
+
+- App launches without panic or ANR.
+- Safe-area insets arrive after the first few frames and shift HUD/modal
+  content away from the status and gesture bars.
+- Every modal's Done button remains above the gesture bar:
+  Settings, Help, Pause, Win Summary, and Leaderboard-related dialogs.
+- Drag-and-drop works on tableau, waste, foundation, and stock/recycle paths.
+- Tap-to-select and one-tap modes both respond correctly on card stacks.
+- Leaderboard panel opens, "Set Name" saves, and the "Public name" label updates
+  while the panel remains open.
+- Rotate the device once, then repeat one modal and one drag operation.
+- Close and relaunch the app; settings/progress still load.
+
+Record the device model, Android version, APK commit, and pass/fail notes in the
+release notes or session handoff. If a failure occurs, keep the filtered logcat
+and note the exact screen/control path that reproduced it.
+
+---
+
+## 5. Platform support matrix
+
+Desktop-only crates and call sites are gated so the workspace cross-compiles.
+Each gate is documented at its call site.
 
 | Surface | Desktop | Android |
 |---------|---------|---------|
 | Bevy windowing | x11 + wayland | `android-native-activity` (NativeActivity glue) |
 | Clipboard ("Copy share link") | `arboard` writes URL | Toast surfaces the URL inline |
-| OS keychain (JWT tokens) | `keyring` v4 → Secret Service / Keychain / Credential Store | Stub returning `KeychainUnavailable`; sync requires fresh login each launch |
+| OS keychain (JWT tokens) | `keyring` v4 → Secret Service / Keychain / Credential Store | Android Keystore via JNI |
+| Data directory | Platform data dir | Android app files dir |
 | App entry point | `bin` target → `solitaire_app::run()` | `cdylib` target loaded by NativeActivity |
 
-What's NOT yet ported / not yet measured:
+Remaining Android follow-ups:
 
-- `dirs::data_dir()` returns `None` on Android. Callers in
-  `solitaire_data/src/storage.rs`, `progress.rs`, `replay.rs`,
-  `achievements.rs`, `settings.rs` all need an Android-aware
-  helper (likely `/data/data/com.ferrousapp.solitaire/files`).
 - Touch UX pass — hit-target sizes, modal scaling on small screens,
   app lifecycle (suspend / resume), font scaling.
-- Android Keystore via JNI for `auth_tokens`.
 - JNI ClipboardManager for share links.
 - Google Play Games sign-in (the `solitaire_gpgs` crate referenced
   in older docs doesn't yet exist).
 
 ---
 
-## 5. Iteration loop
+## 6. Iteration loop
 
 ```bash
 # Edit code…

docs/analytics-validation.md

@@ -0,0 +1,67 @@
+# Analytics Validation Runbook
+
+Ferrous Solitaire currently has two analytics paths:
+
+- Native desktop/Android gameplay events use `solitaire_engine::AnalyticsPlugin`
+  and `solitaire_data::MatomoClient`.
+- Hosted web pages include Matomo page-view snippets in
+  `solitaire_server/web/*.html`.
+
+The Bevy `/play` WASM canvas does not emit the native gameplay events because
+`AnalyticsPlugin` is intentionally gated out on `wasm32`; it depends on the
+native Tokio/reqwest stack.
+
+## Native Matomo Validation
+
+Use this when a deployed Matomo instance and a native build are available.
+
+1. Configure `settings.json` with a Matomo URL and site ID:
+
+   ```json
+   {
+     "analytics_enabled": true,
+     "matomo_url": "https://analytics.example.com",
+     "matomo_site_id": 1
+   }
+   ```
+
+2. Launch the native app and open Settings.
+3. Confirm the Privacy section appears and "Share usage data" is `ON`.
+4. Start a new confirmed game.
+5. Win or forfeit the game.
+6. Unlock an achievement if practical, or use an existing achievement path that
+   is easy to trigger in a test profile.
+7. Wait at least 60 seconds, or close after the win/forfeit path has fired its
+   immediate flush.
+8. In Matomo, confirm the following custom events arrived:
+
+   | Category | Action | Name |
+   | --- | --- | --- |
+   | `Game` | `Start` | `classic`, `zen`, `challenge`, `time_attack`, or `difficulty` |
+   | `Game` | `Won` | empty |
+   | `Game` | `Forfeit` | empty |
+   | `Achievement` | `Unlocked` | achievement id |
+
+## Web/WASM Decision
+
+Keep the current split unless the project explicitly needs in-canvas gameplay
+events for `/play`.
+
+Current behavior:
+
+- `/`, `/play-classic`, `/account`, `/leaderboard`, and `/replays` emit Matomo
+  page views through the hosted HTML snippets.
+- `/play` hosts the Bevy canvas but does not emit gameplay events from the
+  engine.
+- The browser Content-Security-Policy already allows the deployed Matomo host
+  for scripts, images, and connections.
+
+If gameplay events are needed on `/play`, add a small `wasm32`-only analytics
+bridge instead of trying to compile the native plugin:
+
+- keep the same event contract as native (`Game / Start`, `Game / Won`,
+  `Game / Forfeit`, `Achievement / Unlocked`);
+- read `Settings::analytics_enabled`, `matomo_url`, and `matomo_site_id`;
+- send through browser APIs or the existing `_paq` queue;
+- keep the Settings opt-in behavior identical to native;
+- add Playwright coverage that stubs Matomo and verifies emitted payloads.

docs/card-game-integration.md

@@ -2,7 +2,10 @@
 
 **Context:** A collaborator ([Quaternions](https://git.aleshym.co/Quaternions/card_game)) is building a pure-logic Klondike library in Rust. This document maps what that library currently provides against what Ferrous Solitaire's `solitaire_core` crate requires.
 
-**Approach:** Most gaps are closed in Ferrous Solitaire's own `solitaire_core` crate via a wrapper/adapter layer. Gaps 1, 3, and 4 have been addressed upstream. Integration is ready to begin.
+**Approach:** Integration is complete. Upstream `card_game` / `klondike` now owns
+authoritative Klondike rules, session history, undo snapshots, and solving.
+Ferrous keeps product-specific scoring, persistence, rendering DTOs, game modes,
+and typed UI errors in `solitaire_core`.
 
 ---
 
@@ -42,10 +45,12 @@
 
 ---
 
-## What Ferrous Solitaire's `solitaire_core` Needs (Gaps)
+## What Ferrous Solitaire's `solitaire_core` Still Owns
 
 ### 1. Scoring — remaining adapter responsibilities
-Ferrous uses **Windows XP Standard** scoring. The exact table already implemented in `solitaire_core/src/scoring.rs`:
+Ferrous uses **Windows XP Standard** scoring. The upstream library handles the
+per-move counters and configurable deltas; Ferrous adds the product-specific
+parts in `GameState` / `KlondikeAdapter`.
 
 | Event | Delta | Handled by |
 |---|---|---|
@@ -61,11 +66,13 @@ Ferrous uses **Windows XP Standard** scoring. The exact table already implemente
 
 Reference: <https://www.solitaireparadise.com/games_list/klondike_solitaire_scoring.html>
 
-**Undo penalty:** `SessionState::score()` = `KlondikeStats.score(&scoring) + undos × undo_penalty`. The −15 undo penalty is built into `SessionConfig` (default). Once `GameState` fully delegates to `Session`, our `KlondikeAdapter::score_for_undo()` helper becomes redundant.
+**Undo penalty:** `SessionState::score()` = `KlondikeStats.score(&scoring) + undos × undo_penalty`. Ferrous still owns the exact user-visible score because it must restore the pre-move score when undoing recycle penalties and then apply the product's undo penalty.
 
 **Recycle penalty note:** `ScoringConfig::recycle` is a flat delta (default 0 = always free). WXP allows a fixed number of free recycles before charging a penalty, which the upstream library cannot express with a single delta. Our adapter tracks `recycle_count` from `KlondikeStats` and applies the penalty only beyond the free allowance.
 
-**In our wrapper:** Configure `ScoringConfig` with the WXP deltas for the five events upstream handles (including undo via `SessionConfig`). Implement recycle-with-free-allowance, score floor, and time bonus in the adapter.
+**In our wrapper:** `KlondikeAdapter::config_for` configures the upstream rules
+and scoring deltas. `GameState` applies recycle-with-free-allowance, score floor,
+time bonus, game-mode suppression, and undo score restoration.
 
 ### 2. Game Modes
 Ferrous has three modes that alter scoring and undo behaviour:
@@ -78,7 +85,9 @@ Ferrous has three modes that alter scoring and undo behaviour:
 
 Zen is intended for relaxed play where the score does not matter. Challenge is a timed daily puzzle where the no-undo constraint is the difficulty mechanic.
 
-**In our wrapper:** Add `GameMode` to `solitaire_core::GameState`; intercept undo calls and scoring deltas in the adapter before delegating to `KlondikeState`.
+**In our wrapper:** `GameMode` lives on `solitaire_core::GameState`; undo and
+scoring behavior are applied before/after delegating legal moves to the upstream
+session.
 
 ### 3. Solvability Solver *(upstream merged — card_game v0.4.0)*
 `card_game v0.4.0` ships `Session::solve()` — a budget-bounded DFS that returns `Result<Option<Solution<G>>, SolveError>`. `SolveError` has two variants:
@@ -87,23 +96,33 @@ Zen is intended for relaxed play where the score does not matter. Challenge is a
 
 `Solution<G>` contains the winning move sequence as `Vec<StateSnapshot<G>>`; `clean_solution()` removes cycles. `Session::solve()` uses `SessionConfig::solve_moves_budget` and `SessionConfig::solve_states_budget` (defaults: 100 000 each).
 
-Our 767-line `solitaire_core::solver` reimplements the full game rules to run the DFS; `session.solve()` replaces it entirely. The solver will be removed once the `Session<Klondike>` is wired into `GameState`.
+The old local DFS has been replaced. `solitaire_core::solver` is now a small
+adapter around `Session::solve()` that preserves the engine-facing
+`SolverResult`, `SolverConfig`, and first-move payload contract.
 
-**In our wrapper:** Replace `solitaire_core::solver` with `session.solve()`. Map `Ok(Some(_))` → Winnable, `Ok(None)` → Unwinnable, `Err(_)` → Inconclusive.
+**In our wrapper:** `solve_game_state` calls `session.solve()` with the requested
+budgets. It maps `Ok(Some(_))` → Winnable, `Ok(None)` → Unwinnable, and budget
+errors → Inconclusive.
 
 ### 4. `take_from_foundation` House Rule *(upstream merged — v0.3.0)*
 `MoveFromFoundationConfig` is now part of `KlondikeConfig`. When set to `Disallowed`, `is_instruction_valid` blocks foundation → tableau instructions.
 
-**Important:** The upstream default is `MoveFromFoundationConfig::Allowed`. Ferrous Solitaire uses the standard rule (foundation cards cannot be moved back) as the default, with the house rule as an opt-in. Our adapter explicitly sets `Disallowed` in the default `KlondikeConfig` and switches to `Allowed` only when the user toggles the house-rule option.
+**Default behaviour:** The upstream default is `MoveFromFoundationConfig::Allowed`. Ferrous Solitaire **also defaults to Allowed** (`take_from_foundation: true` in `GameState`, `Settings`). This matches the upstream default and provides the most beginner-friendly experience. The player can disable foundation returns via a settings toggle (`take_from_foundation = false`), which maps to `Disallowed`.
 
-**In our wrapper:** Construct `KlondikeConfig { move_from_foundation: MoveFromFoundationConfig::Disallowed, .. }` by default; mirror the user's settings toggle to `Allowed`. No custom intercept needed — `klondike` enforces the rule automatically.
+**In our wrapper:** `KlondikeAdapter::config_for(draw_mode, take_from_foundation)` constructs `KlondikeConfig { move_from_foundation: if take_from_foundation { Allowed } else { Disallowed }, .. }`. No custom intercept needed — `klondike` enforces the rule automatically.
 
 ### 5. JSON Serialisation / Persistence
-`solitaire_core::GameState` serialises the full mid-game state to JSON via `serde` so the engine can save on exit and restore on launch. `KlondikeState` derives `Clone` + `Eq` + `Hash` but not `Serialize` / `Deserialize`. No upstream changes are needed — this is handled externally.
+`solitaire_core::GameState` serialises the full mid-game state to JSON via `serde` so the engine can save on exit and restore on launch.
 
-**Session history:** `StateSnapshot<G>` stores the pre-move game state and instruction. On load, the session is reconstructed from the serialised snapshot history — no full replay from seed needed.
+**Upstream serde status (rev 99b49e62):** At this revision, `klondike` and `card_game` both enable a `serde` feature. All nine instruction/pile types (`KlondikeInstruction`, `KlondikePile`, `KlondikePileStack`, `DstFoundation`, `DstTableau`, `TableauStack`, `Foundation`, `Tableau`, `SkipCards`) derive `serde::Serialize` + `serde::Deserialize` under that feature. The workspace `Cargo.toml` enables `features = ["serde"]`.
 
-**In our wrapper:** Serialise the `solitaire_core` wrapper struct using newtypes. Define `SavedInstruction` (a `Serialize + Deserialize` mirror of `KlondikeInstruction`) and `SavedStateSnapshot`. Reconstruct `SessionState` from the deserialised history. Schema version field lives on our wrapper.
+**Schema v4 (current):** `saved_moves` serialises as `Vec<KlondikeInstruction>` using upstream named-variant serde. Example: `{"DstFoundation": {"src": "Stock", "foundation": "Foundation1"}}`.
+
+**Schema v3 (legacy, auto-migrated):** `saved_moves` used local `SavedInstruction` mirror types with u8 indices. Example: `{"DstFoundation": {"src": "Stock", "foundation": 0}}`. On load, an `AnyInstruction` untagged serde enum transparently upgrades v3 instructions to v4 and the file is written back in v4 format. The `SavedInstruction` bridge types are retained in `solitaire_core::klondike_adapter` for this migration path and for backward-compatible `solitaire_data::ReplayMove` / WASM replay formats.
+
+**Session history:** `StateSnapshot<G>` stores the pre-move game state and instruction. On load, the session is reconstructed by replaying the instruction history against a fresh deal — no full state snapshot needed.
+
+**In our wrapper:** `GameState::Serialize` emits schema v4 (upstream instruction types). `GameState::Deserialize` accepts v3 (auto-migrates) and v4 (direct). Schema version field lives on our wrapper.
 
 ### 6. Typed Move Errors
 `solitaire_core::error::MoveError` returns structured errors the engine uses to trigger UI feedback (wrong-destination toast, stock-empty chime, etc.):
@@ -129,7 +148,9 @@ Ferrous tracks `PileType::Waste` as a distinct pile. `klondike` folds waste into
 ### 8. Undo Stack Approach *(resolved — not an issue)*
 `card_game v0.4.0` `Session` uses snapshot-based undo: `SessionState` stores `Vec<StateSnapshot<G>>` where each entry holds the pre-move game state and the instruction. Undo pops the last snapshot and restores state directly — O(1), matching our existing `GameState.undo_stack`.
 
-**Resolution:** Use `Session`'s built-in snapshot history. Our `GameState.undo_stack: VecDeque<StateSnapshot>` will be removed once `GameState` is fully migrated to delegate to `Session`.
+**Resolution:** `GameState` uses `Session`'s built-in snapshot history. Ferrous
+keeps parallel score/recycle metadata so undo can restore product-specific score
+state that upstream snapshots do not own.
 
 ---
 
@@ -138,12 +159,35 @@ Ferrous tracks `PileType::Waste` as a distinct pile. `klondike` folds waste into
 Steps in dependency order. Upstream issues #10, #11, and the solver are all merged.
 
 1. ✅ **Add `klondike = "0.3.0"` / `card_game = "0.4.0"` as dependencies** of `solitaire_core`; `KlondikeAdapter` wraps `KlondikeConfig` and exposes scoring helpers.
-2. **Map pile types** — project `klondike`'s stock face-up half as `PileType::Waste`; expose the same `HashMap<PileType, Pile>` the engine already reads. Wire `Session<Klondike>` into `KlondikeAdapter` (gap 7).
+2. ✅ **Map pile types** — project `klondike`'s stock face-up half as the engine's waste pile and expose renderer-facing pile snapshots.
-3. ✅ **Configure `KlondikeConfig`** — set `move_from_foundation: MoveFromFoundationConfig::Disallowed` by default; wire the user's house-rule toggle to `Allowed` (gap 4, upstream).
+3. ✅ **Configure `KlondikeConfig`** — set `move_from_foundation: MoveFromFoundationConfig::Allowed` by default; wire the user's settings toggle to `Disallowed` when foundation returns are disabled (gap 4, upstream).
 4. ✅ **Port scoring** — pass WXP deltas into `ScoringConfig`; `SessionConfig::undo_penalty` handles undo; implement recycle-with-free-allowance, score floor, and time bonus in the adapter (gap 1).
 5. ✅ **Port `GameMode`** — intercept undo + scoring in the adapter based on mode (gap 2).
-6. **Replace solver** — call `session.solve()` with budgets from our `SolverConfig`; map `Ok(Some)` → Winnable, `Ok(None)` → Unwinnable, `Err` → Inconclusive (gap 3, upstream).
+6. ✅ **Replace solver** — call `session.solve()` with budgets from `SolverConfig`; map `Ok(Some)` → Winnable, `Ok(None)` → Unwinnable, `Err` → Inconclusive (gap 3, upstream).
-7. **Implement `serde`** — define `SavedInstruction` + `SavedStateSnapshot` newtypes; serialise session history; migrate save-file schema (gap 5).
+7. ✅ **Implement `serde`** — serialise schema v4 with upstream `KlondikeInstruction`; auto-migrate schema v3 via `SavedInstruction` compatibility types.
+
+---
+
+## Quaternions Upgrade Runbook
+
+Use this sequence whenever upgrading `klondike` / `card_game` from the
+Quaternions registry:
+
+1. Review upstream changes/releases:
+   - <https://git.aleshym.co/Quaternions/card_game>
+   - <https://git.aleshym.co/Quaternions/klondike>
+2. Run:
+   ```bash
+   scripts/update_quaternions_deps.sh <klondike_version> <card_game_version>
+   ```
+3. If the script passes, inspect the resulting `Cargo.lock` diff and land the
+   upgrade with the normal PR flow.
+
+The script enforces:
+- lockfile update to requested versions
+- `cargo test --workspace`
+- `cargo clippy --workspace -- -D warnings`
+- deterministic replay/debug-API smoke tests in `solitaire_wasm`
 
 ---
 
@@ -163,5 +207,5 @@ Steps in dependency order. Upstream issues #10, #11, and the solver are all merg
 - Upstream scoring + config PRs: #12 (closes #11), #13 (closes #10)
 - Upstream solver PR: #14
 - `solitaire_core` source: `solitaire_core/src/`
-- Scoring spec: `solitaire_core/src/scoring.rs`
+- Scoring implementation: `solitaire_core/src/game_state.rs`, `solitaire_core/src/klondike_adapter.rs`
 - Architecture overview: `ARCHITECTURE.md`

docs/in-place-card-game-rewrite-plan.md

@@ -0,0 +1,408 @@
+# In-Place card_game / klondike Rewrite Plan
+
+**Date:** 2026-06-08  
+**Upstream rev:** `99b49e62`  
+**Status:** All phases complete (0–3). recycle_count drift and score compound error on undo fixed in `56e3b62`.
+
+---
+
+## 1. What Is Already Integrated
+
+The integration is substantially complete. `solitaire_core` already delegates all
+authoritative Klondike logic to the upstream crates.
+
+| Area | Status | Location |
+|---|---|---|
+| `Session<Klondike>` ownership | ✅ complete | `GameState.session` |
+| `draw()` → `session.process_instruction(RotateStock)` | ✅ complete | `game_state.rs` |
+| `move_cards()` → `session.process_instruction(KlondikeInstruction)` | ✅ complete | `game_state.rs` |
+| `undo()` → `session.undo()` | ✅ complete | `game_state.rs` |
+| `possible_instructions()` → `session.state().state().get_sorted_moves()` | ✅ complete | `game_state.rs` |
+| `can_move_cards()` → `session.state().state().is_instruction_valid()` | ✅ complete | `game_state.rs` |
+| `solver.rs` → `session.solve()` | ✅ complete | `solver.rs` |
+| `Suit`, `Rank` → re-export from `card_game` | ✅ complete | `card.rs` |
+| `Foundation`, `Klondike`, `KlondikePile`, `Session`, `Tableau` → `solitaire_core::lib` | ✅ complete | `lib.rs` |
+| Move legality enforcement | ✅ upstream (`is_instruction_valid`) | `klondike/src/lib.rs` |
+| Foundation placement rules (Ace start, suit match) | ✅ upstream | `klondike/src/lib.rs` |
+| Tableau placement rules (alternating colour, King on empty) | ✅ upstream | `klondike/src/lib.rs` |
+| Multi-card stack moves via `SkipCards` | ✅ upstream | `klondike/src/lib.rs` |
+| Session history / snapshot undo | ✅ upstream | `card_game/src/lib.rs` |
+| DFS solver with budget limits | ✅ upstream | `card_game/src/lib.rs` |
+| Instruction history → `SavedInstruction` serde mirrors | ✅ in adapter | `klondike_adapter.rs` |
+| Schema v3 save/load (instruction replay) | ✅ complete | `game_state.rs`, `storage.rs` |
+| `take_from_foundation` house rule → `MoveFromFoundationConfig` | ✅ complete | `klondike_adapter.rs` |
+
+---
+
+## 2. Duplicated / Replaceable Logic
+
+These are local implementations that either replicate upstream or could be removed.
+
+### 2a. `SavedInstruction` mirror types (~300 lines, `klondike_adapter.rs`)
+
+**What:** A full hand-written serde mirror for every upstream klondike instruction type
+(`SavedInstruction`, `SavedDstFoundation`, `SavedDstTableau`, `SavedKlondikePile`,
+`SavedKlondikePileStack`, `SavedTableauStack`, `SavedTableau`, `SavedFoundation`,
+`SavedSkipCards`, `InvalidSavedInstruction`) plus ~20 `From`/`TryFrom` conversion impls.
+
+**Why written:** At the time, upstream klondike had no serde feature.
+
+**Current upstream status:** At rev `99b49e62`, the `serde` feature is present and active.
+`KlondikeInstruction`, `KlondikePile`, `KlondikePileStack`, `DstFoundation`, `DstTableau`,
+`TableauStack`, `Tableau`, `Foundation`, `SkipCards` all derive
+`#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]`.
+
+**Blocker — JSON format incompatibility:**
+| Field | Local `SavedInstruction` JSON | Upstream `KlondikeInstruction` JSON |
+|---|---|---|
+| Tableau index | `{ "Tableau": 0 }` (u8) | `{ "Tableau": "Tableau1" }` (named) |
+| Foundation slot | `{ "Foundation": 0 }` (u8) | `{ "Foundation": "Foundation1" }` (named) |
+| Skip count | `{ "skip_cards": 0 }` (u8) | `{ "skip_cards": "Skip0" }` (named) |
+
+Switching to direct upstream serde **changes the `saved_moves` JSON shape** stored in
+`game_state.json`. Any existing v3 save file would fail to deserialize after the switch.
+This requires either:
+- A schema bump to v4 **with a migration** (deserialize v3 manually then re-save as v4), or
+- A schema bump to v4 **with graceful fallback** (v3 files rejected → fresh game).
+
+**Recommendation:** Schema v4 with graceful fallback (v3 saves start fresh). Migration
+is feasible but adds ~100 lines of throwaway code; the in-progress game loss is modest
+since schema v3 was never shipped to users (it landed in the current dev branch, not a
+release).
+
+### 2b. `GameState::check_win()` (~15 lines)
+
+**What:** Iterates all four foundation slots checking 13-card A→K sequences.  
+**Upstream equivalent:** `session.state().state().is_win()` on `Klondike`.  
+**Status:** Local check is correct but redundant. Trivially replaceable with no format change.  
+**Risk:** None — only affects `is_won` flag update path.
+
+### 2c. `GameState::check_auto_complete()` (~15 lines)
+
+**What:** Checks stock empty, waste empty, all tableau cards face-up.  
+**Upstream equivalent:** `session.state().state().is_win_trivial()` on `Klondike`.  
+**Semantic difference:** Upstream `is_win_trivial` checks `stock.is_empty()` (both faces)
+and all `tableau.face_down().is_empty()`. Ferrous additionally checks `waste.is_empty()`.
+These are logically equivalent for a valid game state (waste = stock face-up half).  
+**Risk:** Low — validated by existing auto-complete engine tests.
+
+### 2c. `recycle_count` drift on undo (existing bug, not new)
+
+**What:** `GameState.recycle_count` is incremented in `draw()` when stock is empty.
+`undo()` does not decrement it. After undoing a recycle, `recycle_count` is stale and
+may cause incorrect future penalty application.  
+**Upstream:** `KlondikeStats.recycle_count()` has the same problem — it is cumulative
+and not restored on undo (stats are not part of the session snapshot, only game state is).  
+**Fix approach:** After each undo, recompute `recycle_count` by scanning
+`session.history()` for `RotateStock` instructions that caused recycling.  
+**Priority:** Medium — affects scoring correctness in rare paths. File as a separate bug.
+
+---
+
+## 3. What Must Remain Ferrous-Specific
+
+These responsibilities are product-layer, not Klondike-rules-layer, and must stay in `solitaire_core`.
+
+| Responsibility | Why upstream cannot own it |
+|---|---|
+| WXP recycle penalties (free allowance + -100/-20) | `ScoringConfig::recycle` is a flat delta; no free-allowance concept exists upstream |
+| Score floor (`score.max(0)`) | Not modelled upstream |
+| Time bonus (`700_000 / elapsed_seconds`) | Not modelled upstream |
+| `DrawMode` / `GameMode` enums | Product concept; not in upstream |
+| Challenge mode undo block | Product rule |
+| Zen mode scoring suppression | Product rule |
+| `MoveError` variants for UI feedback | Upstream returns `bool`; Ferrous needs typed errors |
+| `card::Card` projection (adds `id`, `face_up`) | Renderer requires stable `id` and face orientation |
+| `Pile` DTO for engine sync | Renderer-facing snapshot type |
+| `stock_cards()` / `waste_cards()` distinction | Engine models waste as a separate pile; upstream uses stock face-up half |
+| `recycle_count` tracking | Needed for free-allowance penalty calculation |
+| Persistence format + schema versioning | Product concern |
+| `SavedInstruction` (currently) or upstream serde (after migration) | Either way, Ferrous owns the save contract |
+
+---
+
+## 4. Key Audit Findings
+
+### Finding 1 — Upstream serde claim in docs is stale
+
+`docs/card-game-integration.md` (last section "JSON Serialisation") states:
+
+> Current verification (2026-06-01): klondike v0.3.0 and card_game v0.4.0 crate manifests
+> expose no serde dependency/feature.
+
+**This is wrong at rev 99b49e62.** The `serde` feature is present and active. All nine
+instruction/pile types have `#[cfg_attr(feature = "serde", derive(...))]`. The doc must
+be updated.
+
+### Finding 2 — `take_from_foundation` default: docs vs code
+
+`docs/card-game-integration.md` says:
+> Ferrous Solitaire uses the standard rule (foundation cards cannot be moved back) as the
+> default, with the house rule as an opt-in.
+
+**The code and settings say the opposite:** `Settings::take_from_foundation` defaults to
+`true` (Allowed); `GameState.take_from_foundation` also initializes to `true`. Multiple
+tests assert this is the intended behavior. The upstream default is also `Allowed`.
+
+**Resolution:** The docs are wrong. Default = Allowed (house rule on by default for
+beginner-friendliness) is intentional. Update the docs; do not change the code.
+
+### Finding 3 — `KlondikeStats` cumulative vs session-history-aware counts
+
+`KlondikeStats.moves()` and `KlondikeStats.recycle_count()` accumulate monotonically.
+They are NOT restored when `Session::undo()` is called (only `Klondike` game state is
+restored from the snapshot, not the stats). Ferrous correctly uses
+`session.history().len()` for `move_count` (history-aware). But `recycle_count` is
+stored separately in `GameState` and also not decremented on undo — making them
+equivalent in this one bug.
+
+### Finding 4 — `SkipCards as usize` cast is correct
+
+Upstream `SkipCards` has no explicit discriminants, so `Skip0 = 0 .. Skip12 = 12`.
+`skip_cards as usize` in `solver.rs` and `game_state.rs` is correct.
+
+---
+
+## 5. Staged Migration
+
+### Phase 0 — Doc fixes only (no code change)
+
+Files: `docs/card-game-integration.md`
+
+- Correct the serde claim (upstream has serde at rev 99b49e62).
+- Correct the `take_from_foundation` default description.
+- Update integration status table.
+
+### Phase 1 — Delegate `is_win` / `is_win_trivial` (safe, no format change)
+
+Files: `solitaire_core/src/game_state.rs`
+
+Replace local `check_win()` and `check_auto_complete()` with upstream delegation:
+
+```rust
+// before
+pub fn check_win(&self) -> bool { ... 40 lines ... }
+
+// after  
+pub fn check_win(&self) -> bool {
+    self.session.state().state().is_win()
+}
+```
+
+```rust
+// before
+pub fn check_auto_complete(&self) -> bool { ... 15 lines ... }
+
+// after
+pub fn check_auto_complete(&self) -> bool {
+    self.session.state().state().is_win_trivial()
+}
+```
+
+**Risk:** Very low. Both methods are tested by existing integration tests. The semantic
+difference in `check_auto_complete` (upstream vs Ferrous definition) is equivalent for
+valid game states.
+
+### Phase 2 — Replace `SavedInstruction` with upstream serde (schema v4)
+
+Files:
+- `solitaire_core/src/klondike_adapter.rs` (remove ~300 lines)
+- `solitaire_core/src/game_state.rs` (update `Serialize`/`Deserialize` impls)
+- `solitaire_core/src/proptest_tests.rs` (remove now-redundant SavedInstruction tests)
+- `solitaire_data/src/storage.rs` (add schema v4 rejection test)
+- `solitaire_data/src/replay.rs` (no change — uses `SavedKlondikePile` independently)
+- `solitaire_wasm/src/lib.rs` (uses `SavedKlondikePileStack` in its own mirror — evaluate)
+
+**Steps:**
+1. In `game_state.rs`, change `PersistedGameState.saved_moves` from
+   `Vec<SavedInstruction>` to `Vec<KlondikeInstruction>` (upstream serde now works).
+2. Update `GameState::Serialize` to emit `KlondikeInstruction` directly.
+3. Update `GameState::Deserialize` to parse `KlondikeInstruction` directly.
+4. Increment `GAME_STATE_SCHEMA_VERSION` to 4.
+5. In `GameState::Deserialize`, reject schema != 4 with graceful fallback (already
+   handled by `load_game_state_from` returning `None` on serde error or wrong version).
+6. Delete `SavedInstruction`, `SavedDstFoundation`, `SavedDstTableau`, `SavedKlondikePile`,
+   `SavedKlondikePileStack`, `SavedTableauStack`, `SavedTableau`, `SavedFoundation`,
+   `SavedSkipCards`, `InvalidSavedInstruction` from `klondike_adapter.rs`.
+7. Delete the 20 `From`/`TryFrom` impls.
+8. Remove `SavedInstruction` proptest and boundary tests (no longer needed).
+9. Add schema v4 round-trip test and v3 rejection test.
+
+**Note on `solitaire_data::replay.rs`:**
+`replay.rs` uses `SavedKlondikePile` independently (for `ReplayMove`). This is a
+separate type from the game-state save format and is NOT changed by this phase.
+`ReplayMove` has its own schema (`REPLAY_SCHEMA_VERSION`) and can keep using the local
+mirror types.
+
+**Note on `solitaire_wasm/src/lib.rs`:**
+Uses `SavedKlondikePileStack` in its own `ReplayMove` mirror. Same as above — separate
+type, not affected.
+
+### Pre-Phase 3 — Undo Field Audit (completed 2026-06-08)
+
+Full audit of every Ferrous-owned field in `GameState` for undo correctness.
+
+| Field | Correctly updated by `undo()`? | Notes |
+|---|---|---|
+| `score` | ✅ By design | −15 WXP undo penalty applied; Zen: stays 0 |
+| `move_count` | ✅ Correct | Recomputed from `session.history().len()` |
+| `is_won` | ✅ Correct | Recomputed; undo blocked on won game |
+| `is_auto_completable` | ✅ Correct | Recomputed |
+| `undo_count` | ✅ By design | Total undos ever, intentionally non-reversible |
+| `elapsed_seconds` | ✅ Intentional | Timer is independent of moves |
+| `seed` / `draw_mode` / `mode` / `take_from_foundation` | ✅ Immutable | |
+| **`recycle_count`** | ❌ **Bug** | Not decremented — see below |
+
+**`recycle_count` drift bug:**
+
+`draw()` increments `recycle_count` when `stock.face_down().is_empty()` (the rotation
+is a recycle, not just a draw). `undo()` calls `session.undo()` which restores the
+`Klondike` card state, but does NOT decrement `recycle_count`.
+
+Consequence: if the player recycles, undoes it, then recycles again, `recycle_count`
+is `2` instead of `1` — the free-recycle allowance is consumed even though the first
+recycle was undone. On Draw-1, the 2nd recycle costs −100; after the undo-and-replay
+bug the player pays −100 for what should be their still-free recycle.
+
+**Score compound effect:** When `undo()` is applied to a recycle that incurred a
+penalty, the penalty amount (`score_after_recycle - 100`) is already in `self.score`.
+`apply_undo_score` then adds `−15` on top. The recycle penalty is never reversed.
+
+**Fix approach for Phase 3:**
+- After `session.undo()`, recompute `recycle_count` by scanning the new
+  `session.history()` for `RotateStock` snapshots where
+  `snapshot.state().state().stock().face_down().is_empty()` (indicating the rotation
+  was a recycle, not a draw from a populated stock).
+- Restore `score` to `snapshot_score` **before** the undone move, then apply only
+  the −15 undo penalty. This requires reading the score stored in `StateSnapshot`
+  or keeping a pre-move score stack alongside the session history.
+
+**Simpler alternative:** Store `(score_before, recycle_count_before)` in `GameState`
+alongside each `session.process_instruction` call, mirroring the snapshot stack.
+Undo pops this alongside the session undo.
+
+### Phase 3 — Fix `recycle_count` drift on undo (optional, post-approval)
+
+Files: `solitaire_core/src/game_state.rs`
+
+After `session.undo()`, recompute `recycle_count` by scanning `session.history()` for
+`RotateStock` snapshots where the pre-instruction stock face-down was empty (indicating
+a recycle). Also correct the score: restore to the pre-undone-move score and apply only
+the −15 undo penalty.
+
+**Tests to add:**
+- `recycle_count_decrements_when_recycle_is_undone`
+- `score_recycle_penalty_is_reversed_on_undo`
+
+**Risk:** Medium — changes observable scoring behavior. The fix is strictly more
+correct, but any golden-file or regression test that recorded the old (buggy) score
+after undo-of-recycle will need updating.
+
+---
+
+## 6. Files Likely to Change Per Phase
+
+| Phase | Files |
+|---|---|
+| Phase 0 | `docs/card-game-integration.md` |
+| Phase 1 | `solitaire_core/src/game_state.rs` |
+| Phase 2 | `solitaire_core/src/klondike_adapter.rs`, `solitaire_core/src/game_state.rs`, `solitaire_core/src/proptest_tests.rs`, `solitaire_data/src/storage.rs` |
+| Phase 3 | `solitaire_core/src/game_state.rs`, new test module |
+
+---
+
+## 7. Risks
+
+### R1 — Save file format break (Phase 2, HIGH)
+Users with v3 saves lose their in-progress game. Mitigated by the fact that v3 is
+not in any shipped release (dev branch only). Graceful fallback (start fresh) is
+acceptable; a migration shim is possible but not required.
+
+### R2 — `solitaire_wasm` / `solitaire_data::replay` breakage (Phase 2, MEDIUM)
+`SavedKlondikePile` and `SavedKlondikePileStack` are also used in `replay.rs` and
+`wasm/src/lib.rs`. These are separate from the game-state save format and must be
+left in place. Plan is to keep them in `klondike_adapter.rs` (or relocate to
+`replay.rs`) after the game-state mirror types are deleted.
+
+### R3 — `check_auto_complete` semantic drift (Phase 1, LOW)
+Upstream `is_win_trivial` checks `stock.is_empty()` (no cards at all in stock)
+whereas Ferrous also checks waste. These are equivalent for a valid game state but
+could differ under test-support pile overrides. Existing auto-complete tests will
+catch any regression.
+
+### R4 — `SkipCards as usize` cast correctness
+Already verified: enums have implicit 0..12 discriminants. No risk.
+
+### R5 — Upstream changes after rev pin
+The workspace is pinned to `rev = "99b49e62"`. No upstream drift risk until explicitly
+re-pinned.
+
+---
+
+## 8. Test Plan
+
+### Phase 1 tests (all currently pass)
+- `game_state::tests::take_from_foundation_allows_legal_return_move`
+- `game_state::tests::take_from_foundation_disabled_blocks_return_move_everywhere`
+- `proptest_tests::*` (card conservation, deal determinism, undo invariant, legal moves)
+
+### Phase 2 tests to add
+- `storage::tests::game_state_v4_mid_game_round_trip` — verify upstream serde round-trip
+  after migrating to `KlondikeInstruction` directly
+- `storage::tests::save_format_v3_is_rejected` — v3 files must return `None`
+- Update `game_state::tests::*` — all existing tests must continue to pass
+
+### Phase 2 tests to remove
+- `proptest_tests::saved_instruction_round_trip` — no longer needed (no mirror types)
+- `proptest_tests::saved_instruction_boundary_tests::*` — no longer needed
+
+### Phase 3 tests to add
+- `game_state::tests::recycle_count_decrements_on_undo` — after recycling and undoing,
+  `recycle_count` must reflect the correct post-undo count
+
+---
+
+## 9. Validation Commands
+
+Run after each phase:
+
+```bash
+# Targeted (fast)
+cargo test -p solitaire_core
+cargo clippy -p solitaire_core -- -D warnings
+
+# Broader
+cargo test -p solitaire_wasm
+cargo test -p solitaire_data
+
+# Full workspace (run before declaring phase complete)
+cargo test --workspace
+cargo clippy --workspace -- -D warnings
+```
+
+---
+
+## Summary: What Would Be Removed vs Kept
+
+### Removed after all phases complete
+| Code | Lines est. | Reason |
+|---|---|---|
+| `SavedInstruction` + 8 mirror types | ~150 | Upstream serde now available |
+| 20 `From`/`TryFrom` impls | ~150 | Upstream serde now available |
+| `InvalidSavedInstruction` error type | ~10 | Upstream serde now available |
+| `check_win()` local impl | ~20 | Replaced by `is_win()` delegation |
+| `check_auto_complete()` local impl | ~15 | Replaced by `is_win_trivial()` delegation |
+| `SavedInstruction` proptest + boundary tests | ~60 | Mirror types removed |
+
+**Total: ~400 lines removed from `solitaire_core`**
+
+### Remains Ferrous-specific
+- `KlondikeAdapter` scoring helpers (recycle penalties, score floor, time bonus, Zen/mode suppression)
+- `DrawMode`, `GameMode`, `DifficultyLevel`
+- `MoveError` and all boundary-checking logic
+- `card::Card` (id + face_up projection)
+- `Pile` DTO
+- `stock_cards()` / `waste_cards()` projections
+- Persistence format (`GameState` serde, schema version, `PersistedGameState`)
+- `solitaire_data::replay` types (`ReplayMove`, `SavedKlondikePile` mirror — unchanged)
+- `solitaire_wasm` replay mirror types (unchanged)

docs/testing-architecture.md

@@ -0,0 +1,115 @@
+# Testing Architecture — Engine-first Validation
+
+Ferrous Solitaire validation is split into three layers with clear ownership:
+
+1. **Rust unit tests (`solitaire_core`)**
+   - move generation and legality
+   - deal generation determinism
+   - scoring and penalties
+   - undo semantics
+   - win detection
+
+2. **Engine integration tests (`solitaire_wasm` debug API)**
+   - autonomous game execution without UI/pointer simulation
+   - invariant checks after every move
+   - deterministic seed replay
+   - high-volume seeded runs (including long-running soak tests)
+
+3. **Playwright UI tests**
+   - verify rendering vs engine state
+   - drag/drop and keyboard UX behavior
+   - responsive layout behavior
+   - browser-compatibility checks
+
+## Source of truth
+
+The Rust engine is authoritative. Browser tests must interact with the game via
+debug API hooks, not via pixel/OCR solving or hardcoded screen coordinates.
+
+## Debug API surfaces
+
+Two automation surfaces are exposed:
+
+- `solitaire_wasm::SolitaireGame` methods:
+  - `debug_snapshot()`
+  - `debug_legal_moves()`
+  - `debug_move_history()`
+  - `debug_apply_legal_move(index)`
+  - `debug_apply_move_json(json)`
+- Browser bridge on `game.html`:
+  - `window.__FERROUS_DEBUG__.snapshot()`
+  - `window.__FERROUS_DEBUG__.legalMoves()`
+  - `window.__FERROUS_DEBUG__.moveHistory()`
+  - `window.__FERROUS_DEBUG__.applyLegalMove(index)`
+  - `window.__FERROUS_DEBUG__.applyMove(move)`
+  - `window.__FERROUS_DEBUG__.failureReport()`
+  - `window.__FERROUS_DEBUG__.runAutoplay(options)`
+
+## Required failure payload
+
+Every automation failure should capture:
+
+- seed
+- move history
+- current game state
+- screenshot
+- browser trace
+- console logs
+
+`failureReport()` provides the engine-side fields (`seed`, `moveHistory`,
+`currentState`) so UI harnesses only need to attach browser artifacts.
+
+## Execution guidance
+
+- Fast verification:
+  - `cargo test -p solitaire_core -p solitaire_wasm`
+- Full verification:
+  - `cargo test --workspace`
+  - `cargo clippy --workspace -- -D warnings`
+- Long unattended soak:
+  - `cargo test -p solitaire_wasm debug_api_autonomous_thousands_seed_soak -- --ignored`
+
+### Browser e2e harness
+
+The Playwright suite lives under `solitaire_server/e2e/` and boots
+`solitaire_server` via Playwright `webServer` config.
+
+- Install + run:
+  - `cd solitaire_server/e2e`
+  - `npm ci`
+  - `npx playwright install chromium`
+  - `npm test`
+- Cycle metrics batch run:
+  - `cd solitaire_server/e2e`
+  - `npm run review:cycles -- --games 1000 --steps 350 --policy baseline --max-visits 1 --out /tmp/cycle-baseline.json`
+  - `npm run review:cycles -- --games 1000 --steps 350 --policy loop_aware --max-visits 2 --out /tmp/cycle-loop-aware.json`
+  - `npm run review:cycles:regression` (thresholded gate, writes `test-results/cycle-regression.json`)
+  - `npm run review:cycles:candidate` (loop-aware candidate run, writes `test-results/cycle-candidate.json`)
+
+### Cycle-risk regression baseline and guardrails
+
+- Current regression gate command:
+  - `npm run review:cycles:regression`
+  - config: `games=240`, `steps=350`, `policy=baseline`, `max-visits=1`
+- Current guardrail thresholds:
+  - `all.cycle_rate_pct <= 86`
+  - `draw1.cycle_rate_pct <= 76`
+  - `draw3.cycle_rate_pct <= 95`
+  - `all.win_rate_pct >= 14`
+  - zero invariant/apply/page/console issue counts
+- Baseline sample (240 games):
+  - overall: `win_rate=15.8%`, `cycle_rate=84.2%`
+  - draw-one: `win_rate=25.8%`, `cycle_rate=74.2%`
+  - draw-three: `win_rate=5.8%`, `cycle_rate=94.2%`
+- Candidate loop-aware sample (240 games, lookahead via simulated move + restore):
+  - overall: `win_rate=20.4%`, `cycle_rate=32.5%`
+  - draw-one: `win_rate=33.3%`, `cycle_rate=16.7%`
+  - draw-three: `win_rate=7.5%`, `cycle_rate=48.3%`
+  - no invariant/apply/page/console issues in the sampled run
+- Additional 500-game candidate soak:
+  - overall: `win_rate=20.2%`, `cycle_rate=28.6%`, `step_budget=51.2%`
+  - draw-three remains the dominant risk (`cycle_rate=45.2%`)
+- Fix applied: cycle metrics regression now supports explicit
+  `max_step_budget_rate_*` thresholds. Candidate command now enforces
+  `max_step_budget_rate_all <= 60` to prevent silent drift from cycles into
+  step-budget stalls.

scripts/ANDROID_TESTING.md

@@ -0,0 +1,228 @@
+# Android testing
+
+This directory contains lightweight Android test helpers for Ferrous Solitaire.
+They are intended to run against either a physical Android device or an emulator
+connected through `adb`. When no device is connected the smoke script can
+automatically launch an AVD for you.
+
+## Prerequisites
+
+- Android SDK and NDK installed.
+- `adb` available on `PATH`.
+- One device/emulator visible in `adb devices`, **or** at least one AVD created
+  (the script will launch one automatically if `LAUNCH_AVD=1`, which is the default).
+- If multiple devices are connected, set `ADB_SERIAL` to the target device serial.
+- Environment variables required by `scripts/build_android_apk.sh` when building:
+
+```sh
+export ANDROID_HOME=/path/to/android-sdk
+export ANDROID_NDK_HOME=/path/to/android-ndk
+export BUILD_TOOLS_VERSION=34.0.0
+export PLATFORM=android-34
+```
+
+## Smoke test
+
+From the workspace root (`Rusty_Solitaire/`):
+
+```sh
+scripts/android_smoke.sh
+```
+
+The smoke test first checks whether `adb` can see a ready device. If no device
+is connected and `LAUNCH_AVD=1` (default), it:
+
+1. locates the `emulator` binary under `ANDROID_HOME` or `PATH`,
+2. picks the first available AVD (or uses `AVD_NAME`),
+3. launches the emulator in the foreground (or headless with `AVD_HEADLESS=1`),
+4. waits for `sys.boot_completed=1` before proceeding,
+5. dismisses the lock screen so the screenshot shows the app.
+
+Once a device is ready (auto-launched or pre-existing) the script:
+
+1. builds the APK using `scripts/build_android_apk.sh`,
+2. installs it with `adb install -r -d` so debug smoke builds can replace newer local builds,
+3. force-stops the package by default for a clean launch,
+4. clears `logcat`,
+5. launches `com.ferrousapp.solitaire/android.app.NativeActivity`,
+6. waits for the app to settle,
+7. verifies the process is still running,
+8. captures a screenshot and `logcat`, and
+9. fails on fatal log patterns such as native crashes, JNI fatal errors, real ANRs,
+   and Rust panics.
+
+On exit the script kills any emulator it launched (`SHUTDOWN_AVD_ON_EXIT=1` by
+default). Set `SHUTDOWN_AVD_ON_EXIT=0` to keep the emulator open for inspection.
+
+Artifacts are written to `target/android-smoke/<timestamp>/` by default. A successful run includes:
+
+- `device.txt` — selected device and display metadata,
+- `df-data-before.txt` / `df-data-after.txt` — emulator/device storage snapshots,
+- `emulator.log` — stdout/stderr from the emulator process (AVD runs only),
+- `emulator.pid` — PID of the emulator process (AVD runs only),
+- `launch.png` — screenshot after the wait period,
+- `logcat.txt` — full captured log,
+- `log-summary.txt` — grep summary for warnings, errors, JNI, safe-area, and crash terms, and
+- `pid.txt` — running app process id.
+
+## Creating an AVD
+
+If no AVDs exist, create one before running the smoke test:
+
+```sh
+# Install a system image
+"$ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager" \
+  'system-images;android-34;google_apis;x86_64'
+
+# Create the AVD
+"$ANDROID_HOME/cmdline-tools/latest/bin/avdmanager" create avd \
+  -n Pixel_7_API_34 \
+  -k 'system-images;android-34;google_apis;x86_64' \
+  --device 'pixel_7'
+```
+
+Then run the smoke test — it will pick `Pixel_7_API_34` automatically:
+
+```sh
+scripts/android_smoke.sh
+```
+
+## Faster iteration
+
+If you already built the APK and only want to reinstall/relaunch:
+
+```sh
+BUILD_APK=0 scripts/android_smoke.sh
+```
+
+If the APK is already installed and you only want to relaunch/capture logs:
+
+```sh
+BUILD_APK=0 INSTALL_APK=0 scripts/android_smoke.sh
+```
+
+By default the script force-stops the package before launch so logcat and screenshots represent a clean app start. To test warm-launch behavior instead:
+
+```sh
+BUILD_APK=0 INSTALL_APK=0 FORCE_STOP=0 scripts/android_smoke.sh
+```
+
+This is also useful when an already-installed build is good enough for launch/log checks. On install failure, the script writes `adb-install.txt`, storage snapshots, and installed-package diagnostics to the output directory.
+
+If install fails with `INSTALL_FAILED_UPDATE_INCOMPATIBLE`, the smoke script uninstalls the package and retries once by default (`RESET_ON_SIGNATURE_MISMATCH=1`). This resets app data on the device/emulator. Disable it with:
+
+```sh
+RESET_ON_SIGNATURE_MISMATCH=0 scripts/android_smoke.sh
+```
+
+To write artifacts to a stable path:
+
+```sh
+OUT_DIR=target/android-smoke/latest scripts/android_smoke.sh
+```
+
+When reusing an output directory, previous files are removed by default so stale artifacts do not contaminate the latest result. To keep existing files:
+
+```sh
+CLEAN_OUT_DIR=0 OUT_DIR=target/android-smoke/latest scripts/android_smoke.sh
+```
+
+To target a specific device when more than one is attached:
+
+```sh
+ADB_SERIAL=emulator-5554 scripts/android_smoke.sh
+```
+
+To wait longer for safe-area inset polling or slow devices:
+
+```sh
+WAIT_SECS=8 scripts/android_smoke.sh
+```
+
+## AVD options
+
+To pick a specific AVD by name instead of auto-selecting the first one:
+
+```sh
+AVD_NAME=Pixel_7_API_34 scripts/android_smoke.sh
+```
+
+To run headless (no emulator window) — useful in CI or on a display-less machine:
+
+```sh
+AVD_HEADLESS=1 scripts/android_smoke.sh
+```
+
+To give a slow machine more time to boot the emulator (default is 120 s):
+
+```sh
+AVD_BOOT_TIMEOUT=180 scripts/android_smoke.sh
+```
+
+To keep the emulator running after the test (useful for manual inspection):
+
+```sh
+SHUTDOWN_AVD_ON_EXIT=0 scripts/android_smoke.sh
+```
+
+To pass extra flags to the emulator (e.g. disable snapshot for a completely
+cold boot, or change GPU mode):
+
+```sh
+AVD_EXTRA_ARGS="-gpu swiftshader_indirect" scripts/android_smoke.sh
+```
+
+To disable AVD auto-launch entirely and fail immediately if no device is
+connected:
+
+```sh
+LAUNCH_AVD=0 scripts/android_smoke.sh
+```
+
+For build-only validation without requiring a connected device, use the lower-level APK builder directly:
+
+```sh
+scripts/build_android_apk.sh
+```
+
+For smoke testing, `scripts/android_smoke.sh` defaults to the connected device's primary ABI when `BUILD_APK=1`, which keeps emulator APKs much smaller than the full multi-ABI default. You can still override it explicitly:
+
+```sh
+ABIS=x86_64 scripts/android_smoke.sh
+```
+
+For build-only validation, `scripts/build_android_apk.sh` still defaults to all configured ABIs unless you set `ABIS` yourself:
+
+```sh
+ABIS=x86_64 scripts/build_android_apk.sh
+```
+
+The APK builder signs debug builds with a persistent keystore at `target/android/debug.keystore` by default. This avoids signature churn across smoke-test runs.
+
+The APK builder also strips native debug symbols by default before packaging (`STRIP_NATIVE_LIBS=1`). This keeps debug APKs installable on emulators with limited `/data` storage. To preserve native debug symbols for low-level debugging:
+
+```sh
+STRIP_NATIVE_LIBS=0 ABIS=x86_64 scripts/build_android_apk.sh
+```
+
+## Device checklist
+
+The script is only a smoke test. Before shipping Android builds, also verify:
+
+- safe-area insets arrive and shift the HUD after a few seconds,
+- HUD does not overlap the top status bar,
+- modal Done buttons are above the gesture/navigation bar,
+- stock tap works,
+- drag-and-drop works on tableau, waste, and foundation piles,
+- Settings/Help/Profile modals open and close,
+- login tokens persist after app restart, and
+- `target/android-smoke/.../logcat.txt` contains no fatal JNI/native crash output.
+
+## Notes
+
+- `adb shell input tap X Y` uses physical pixels, not Bevy logical pixels.
+- The project’s common test device mapping is physical `1080×2400`, Bevy logical
+  `900×2000`, scale factor `1.20`; multiply logical coordinates by `1.20` for
+  scripted `adb shell input` commands on that device.
+- Keep generated screenshots/logs under `target/android-smoke/` so they stay out
+  of source control.

scripts/android_smoke.sh

@@ -0,0 +1,362 @@
+#!/usr/bin/env bash
+# Android smoke test for Ferrous Solitaire.
+#
+# Builds (optional), installs, launches, captures logcat + screenshot, and
+# fails on fatal Android log patterns. Designed as a lightweight device/emulator
+# sanity check rather than a full UI automation suite.
+#
+# Required:
+#   adb on PATH
+#   Android SDK/NDK env required by scripts/build_android_apk.sh when BUILD_APK=1
+#
+# Optional environment:
+#   BUILD_APK=1|0          Build APK before install (default: 1)
+#   INSTALL_APK=1|0        Install APK before launch (default: 1)
+#   RESET_ON_SIGNATURE_MISMATCH=1|0
+#                           Uninstall/retry if debug signatures differ (default: 1)
+#   LAUNCH_APP=1|0         Launch app before checks (default: 1)
+#   FORCE_STOP=1|0         Force-stop package before launch for clean logs (default: 1)
+#   CAPTURE_SCREENSHOT=1|0 Capture screenshot (default: 1)
+#   ADB_SERIAL=...         Device serial to use when multiple devices are connected
+#   APK_PATH=...           APK to install (default: target/debug/apk/ferrous-solitaire.apk)
+#   PACKAGE=...            Android package (default: com.ferrousapp.solitaire)
+#   ACTIVITY=...           Activity class (default: android.app.NativeActivity)
+#   OUT_DIR=...            Artifact directory (default: target/android-smoke/<timestamp>)
+#   CLEAN_OUT_DIR=1|0      Remove prior artifacts from OUT_DIR first (default: 1)
+#   WAIT_SECS=...          Seconds to wait after launch (default: 5)
+#   ABIS=...               Passed to build script. If unset and BUILD_APK=1,
+#                           defaults to the connected device's primary ABI.
+#
+# AVD auto-launch (used when no device/emulator is already connected):
+#   LAUNCH_AVD=1|0         Auto-launch an AVD when no device is ready (default: 1)
+#   AVD_NAME=...           AVD name to launch (default: first from `emulator -list-avds`)
+#   AVD_BOOT_TIMEOUT=...   Seconds to wait for the emulator to finish booting (default: 120)
+#   AVD_HEADLESS=1|0       Run with -no-window -no-audio for CI/no-display environments (default: 0)
+#   AVD_EXTRA_ARGS=...     Extra arguments appended verbatim to the emulator command line
+#   SHUTDOWN_AVD_ON_EXIT=1|0
+#                           Kill the AVD this script launched on exit (default: 1).
+#                           Set to 0 to leave the emulator running after the test.
+#
+# Examples:
+#   scripts/android_smoke.sh
+#   BUILD_APK=0 scripts/android_smoke.sh
+#   LAUNCH_AVD=0 scripts/android_smoke.sh            # error out if no device, never auto-launch
+#   AVD_NAME=Pixel_7_API_34 scripts/android_smoke.sh
+#   AVD_HEADLESS=1 scripts/android_smoke.sh          # CI / no-display
+#   SHUTDOWN_AVD_ON_EXIT=0 scripts/android_smoke.sh  # keep emulator open after test
+#   OUT_DIR=target/android-smoke/latest WAIT_SECS=8 scripts/android_smoke.sh
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+cd "$REPO_ROOT"
+
+BUILD_APK="${BUILD_APK:-1}"
+INSTALL_APK="${INSTALL_APK:-1}"
+RESET_ON_SIGNATURE_MISMATCH="${RESET_ON_SIGNATURE_MISMATCH:-1}"
+LAUNCH_APP="${LAUNCH_APP:-1}"
+FORCE_STOP="${FORCE_STOP:-1}"
+CAPTURE_SCREENSHOT="${CAPTURE_SCREENSHOT:-1}"
+APK_PATH="${APK_PATH:-target/debug/apk/ferrous-solitaire.apk}"
+PACKAGE="${PACKAGE:-com.ferrousapp.solitaire}"
+ACTIVITY="${ACTIVITY:-android.app.NativeActivity}"
+WAIT_SECS="${WAIT_SECS:-5}"
+OUT_DIR="${OUT_DIR:-target/android-smoke/$(date +%Y%m%d-%H%M%S)}"
+CLEAN_OUT_DIR="${CLEAN_OUT_DIR:-1}"
+REMOTE_SCREENSHOT="/sdcard/ferrous-solitaire-smoke.png"
+
+LAUNCH_AVD="${LAUNCH_AVD:-1}"
+AVD_NAME="${AVD_NAME:-}"
+AVD_BOOT_TIMEOUT="${AVD_BOOT_TIMEOUT:-120}"
+AVD_HEADLESS="${AVD_HEADLESS:-0}"
+AVD_EXTRA_ARGS="${AVD_EXTRA_ARGS:-}"
+SHUTDOWN_AVD_ON_EXIT="${SHUTDOWN_AVD_ON_EXIT:-1}"
+
+ADB=(adb)
+if [ -n "${ADB_SERIAL:-}" ]; then
+  ADB+=( -s "$ADB_SERIAL" )
+fi
+
+# PID of any emulator we start so the EXIT trap can clean it up.
+_LAUNCHED_EMULATOR_PID=""
+
+_cleanup_emulator() {
+  if [ -n "$_LAUNCHED_EMULATOR_PID" ] && [ "$SHUTDOWN_AVD_ON_EXIT" = "1" ]; then
+    echo ">>> shutdown emulator (PID $_LAUNCHED_EMULATOR_PID)"
+    kill "$_LAUNCHED_EMULATOR_PID" 2>/dev/null || true
+  fi
+}
+trap _cleanup_emulator EXIT
+
+require_cmd() {
+  command -v "$1" >/dev/null 2>&1 || {
+    echo "missing required command: $1" >&2
+    exit 1
+  }
+}
+
+mkdir -p "$OUT_DIR"
+if [ "$CLEAN_OUT_DIR" = "1" ]; then
+  find "$OUT_DIR" -mindepth 1 -maxdepth 1 -exec rm -rf {} +
+fi
+require_cmd adb
+
+# ---------------------------------------------------------------------------
+# Device / emulator availability
+# ---------------------------------------------------------------------------
+DEVICE_STATE="$("${ADB[@]}" get-state 2>/dev/null || true)"
+if [ "$DEVICE_STATE" != "device" ]; then
+  if [ "$LAUNCH_AVD" != "1" ]; then
+    adb devices > "$OUT_DIR/adb-devices.txt" 2>&1 || true
+    if [ -n "${ADB_SERIAL:-}" ]; then
+      echo "Android device '$ADB_SERIAL' is not connected/ready (state: ${DEVICE_STATE:-unknown})." >&2
+    else
+      echo "No Android device/emulator is connected and ready." >&2
+    fi
+    echo "Run 'adb devices' or start an emulator, then retry." >&2
+    echo "Device list saved to $OUT_DIR/adb-devices.txt" >&2
+    exit 1
+  fi
+
+  # --- locate emulator binary -----------------------------------------------
+  # Priority: ANDROID_HOME env → PATH → common SDK install locations.
+  _find_sdk_root() {
+    for candidate in \
+        "$HOME/Android/Sdk" \
+        "$HOME/Library/Android/sdk" \
+        "/opt/android-sdk" \
+        "/usr/lib/android-sdk"; do
+      [ -d "$candidate" ] && echo "$candidate" && return
+    done
+  }
+
+  EMULATOR_BIN=""
+  if [ -n "${ANDROID_HOME:-}" ] && [ -x "$ANDROID_HOME/emulator/emulator" ]; then
+    EMULATOR_BIN="$ANDROID_HOME/emulator/emulator"
+  elif command -v emulator >/dev/null 2>&1; then
+    EMULATOR_BIN="$(command -v emulator)"
+  else
+    _SDK_ROOT="$(_find_sdk_root)"
+    if [ -n "$_SDK_ROOT" ] && [ -x "$_SDK_ROOT/emulator/emulator" ]; then
+      EMULATOR_BIN="$_SDK_ROOT/emulator/emulator"
+    fi
+  fi
+
+  if [ -z "$EMULATOR_BIN" ]; then
+    echo "No Android device found and 'emulator' binary is not available." >&2
+    echo "  • Install the Android SDK emulator component, or" >&2
+    echo "  • Set ANDROID_HOME to your SDK root, or" >&2
+    echo "  • Start a device/emulator manually then retry with LAUNCH_AVD=0." >&2
+    exit 1
+  fi
+  echo ">>> emulator binary: $EMULATOR_BIN"
+
+  # --- select AVD -----------------------------------------------------------
+  if [ -z "$AVD_NAME" ]; then
+    AVD_NAME="$("$EMULATOR_BIN" -list-avds 2>/dev/null | head -n 1 | tr -d '\r')"
+    if [ -z "$AVD_NAME" ]; then
+      echo "No AVDs found. Create one first, for example:" >&2
+      echo "  sdkmanager 'system-images;android-34;google_apis;x86_64'" >&2
+      echo "  avdmanager create avd -n Pixel_7_API_34 \\" >&2
+      echo "    -k 'system-images;android-34;google_apis;x86_64' --device 'pixel_7'" >&2
+      exit 1
+    fi
+    echo ">>> auto-selected AVD: $AVD_NAME"
+  fi
+
+  # --- launch emulator -------------------------------------------------------
+  EMULATOR_ARGS=( -avd "$AVD_NAME" -no-snapshot-load )
+  [ "$AVD_HEADLESS" = "1" ] && EMULATOR_ARGS+=( -no-window -no-audio )
+  # Split AVD_EXTRA_ARGS on whitespace only (disable glob expansion).
+  set -f
+  # shellcheck disable=SC2206
+  [ -n "$AVD_EXTRA_ARGS" ] && EMULATOR_ARGS+=( $AVD_EXTRA_ARGS )
+  set +f
+
+  echo ">>> launch emulator: $AVD_NAME"
+  "$EMULATOR_BIN" "${EMULATOR_ARGS[@]}" > "$OUT_DIR/emulator.log" 2>&1 &
+  _LAUNCHED_EMULATOR_PID=$!
+  echo "$_LAUNCHED_EMULATOR_PID" > "$OUT_DIR/emulator.pid"
+  echo "    emulator PID: $_LAUNCHED_EMULATOR_PID"
+  echo "    emulator log: $OUT_DIR/emulator.log"
+
+  # --- wait for adb transport -----------------------------------------------
+  # Poll adb get-state (≠ wait-for-device which blocks indefinitely) so we can
+  # honour AVD_BOOT_TIMEOUT for the whole boot sequence.
+  echo ">>> waiting for device to appear in adb (timeout: ${AVD_BOOT_TIMEOUT}s)"
+  _ELAPSED=0
+  while true; do
+    _STATE="$("${ADB[@]}" get-state 2>/dev/null || true)"
+    if [ "$_STATE" = "device" ] || [ "$_STATE" = "offline" ]; then
+      break
+    fi
+    if [ "$_ELAPSED" -ge "$AVD_BOOT_TIMEOUT" ]; then
+      echo "Device did not appear in adb within ${AVD_BOOT_TIMEOUT}s" >&2
+      echo "emulator log:" >&2
+      tail -20 "$OUT_DIR/emulator.log" >&2 || true
+      exit 1
+    fi
+    sleep 3
+    _ELAPSED=$(( _ELAPSED + 3 ))
+    echo "    ... ${_ELAPSED}s / ${AVD_BOOT_TIMEOUT}s"
+  done
+
+  # Capture emulator serial (emulator-5554 etc.) so all subsequent adb calls
+  # target the right device when ADB_SERIAL was not set by the caller.
+  if [ -z "${ADB_SERIAL:-}" ]; then
+    _EMU_SERIAL="$(adb devices 2>/dev/null | awk '/^emulator-/{print $1; exit}' | tr -d '\r')"
+    if [ -n "$_EMU_SERIAL" ]; then
+      ADB_SERIAL="$_EMU_SERIAL"
+      ADB=(adb -s "$ADB_SERIAL")
+      echo ">>> detected emulator serial: $ADB_SERIAL"
+    fi
+  fi
+
+  # --- wait for full Android boot -------------------------------------------
+  # adb get-state returning "device" means the transport is up, but the
+  # Android framework may still be initialising. Poll sys.boot_completed.
+  echo ">>> waiting for boot_completed (timeout: ${AVD_BOOT_TIMEOUT}s)"
+  _BOOT_ELAPSED=0
+  _BOOT_INTERVAL=5
+  while true; do
+    _BOOT="$("${ADB[@]}" shell getprop sys.boot_completed 2>/dev/null | tr -d '\r')"
+    if [ "$_BOOT" = "1" ]; then
+      echo ">>> emulator boot complete"
+      break
+    fi
+    if [ "$_BOOT_ELAPSED" -ge "$AVD_BOOT_TIMEOUT" ]; then
+      echo "Emulator did not finish booting within ${AVD_BOOT_TIMEOUT}s" >&2
+      echo "emulator log:" >&2
+      tail -20 "$OUT_DIR/emulator.log" >&2 || true
+      exit 1
+    fi
+    sleep "$_BOOT_INTERVAL"
+    _BOOT_ELAPSED=$(( _BOOT_ELAPSED + _BOOT_INTERVAL ))
+    echo "    ... ${_BOOT_ELAPSED}s / ${AVD_BOOT_TIMEOUT}s (boot_completed='${_BOOT}')"
+  done
+
+  # Dismiss the lock screen so later screencap shows the app, not the keyguard.
+  "${ADB[@]}" shell input keyevent 82 2>/dev/null || true
+
+  # Final sanity check — device must be fully ready before we proceed.
+  DEVICE_STATE="$("${ADB[@]}" get-state 2>/dev/null || true)"
+  if [ "$DEVICE_STATE" != "device" ]; then
+    echo "Emulator is running but adb state is '${DEVICE_STATE:-unknown}'." >&2
+    exit 1
+  fi
+fi
+
+# ---------------------------------------------------------------------------
+# Device metadata
+# ---------------------------------------------------------------------------
+{
+  echo "adb_serial=${ADB_SERIAL:-default}"
+  echo "package=$PACKAGE"
+  echo "activity=$ACTIVITY"
+  echo "device_state=$DEVICE_STATE"
+  "${ADB[@]}" shell getprop ro.product.model 2>/dev/null | tr -d '\r' | sed 's/^/product_model=/'
+  "${ADB[@]}" shell getprop ro.build.version.release 2>/dev/null | tr -d '\r' | sed 's/^/android_release=/'
+  "${ADB[@]}" shell getprop ro.build.version.sdk 2>/dev/null | tr -d '\r' | sed 's/^/android_sdk=/'
+  "${ADB[@]}" shell wm size 2>/dev/null | tr -d '\r' | sed 's/^/wm_size=/'
+  "${ADB[@]}" shell wm density 2>/dev/null | tr -d '\r' | sed 's/^/wm_density=/'
+} > "$OUT_DIR/device.txt"
+"${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-before.txt" 2>&1 || true
+
+if [ "$BUILD_APK" = "1" ]; then
+  if [ -z "${ABIS:-}" ]; then
+    DEVICE_ABI="$("${ADB[@]}" shell getprop ro.product.cpu.abi 2>/dev/null | tr -d '\r')"
+    case "$DEVICE_ABI" in
+      x86_64|arm64-v8a|armeabi-v7a)
+        export ABIS="$DEVICE_ABI"
+        ;;
+      armeabi*)
+        export ABIS="armeabi-v7a"
+        ;;
+      *)
+        echo "Could not map device ABI '$DEVICE_ABI'; using build script default ABIS." >&2
+        ;;
+    esac
+  fi
+  echo ">>> build Android APK${ABIS:+ (ABIS=$ABIS)}"
+  scripts/build_android_apk.sh
+fi
+
+if [ "$INSTALL_APK" = "1" ]; then
+  [ -f "$APK_PATH" ] || {
+    echo "APK not found: $APK_PATH" >&2
+    echo "Set APK_PATH or run with BUILD_APK=1." >&2
+    exit 1
+  }
+  ls -lh "$APK_PATH" > "$OUT_DIR/apk.txt"
+  echo ">>> install $APK_PATH"
+  if ! "${ADB[@]}" install -r -d "$APK_PATH" > "$OUT_DIR/adb-install.txt" 2>&1; then
+    if [ "$RESET_ON_SIGNATURE_MISMATCH" = "1" ] && grep -q "INSTALL_FAILED_UPDATE_INCOMPATIBLE" "$OUT_DIR/adb-install.txt"; then
+      echo ">>> signature mismatch; uninstalling $PACKAGE and retrying install"
+      "${ADB[@]}" uninstall "$PACKAGE" > "$OUT_DIR/adb-uninstall-before-retry.txt" 2>&1 || true
+      if "${ADB[@]}" install -r -d "$APK_PATH" > "$OUT_DIR/adb-install-retry.txt" 2>&1; then
+        cat "$OUT_DIR/adb-install-retry.txt" >> "$OUT_DIR/adb-install.txt"
+      else
+        cat "$OUT_DIR/adb-install.txt" >&2
+        cat "$OUT_DIR/adb-install-retry.txt" >&2
+        "${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-after-install-failure.txt" 2>&1 || true
+        "${ADB[@]}" shell pm list packages | grep -F "$PACKAGE" > "$OUT_DIR/installed-package.txt" 2>&1 || true
+        echo "APK install retry failed. Diagnostics saved in $OUT_DIR" >&2
+        exit 1
+      fi
+    else
+      cat "$OUT_DIR/adb-install.txt" >&2
+      "${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-after-install-failure.txt" 2>&1 || true
+      "${ADB[@]}" shell pm list packages | grep -F "$PACKAGE" > "$OUT_DIR/installed-package.txt" 2>&1 || true
+      echo "APK install failed. Diagnostics saved in $OUT_DIR" >&2
+      echo "If the package is already installed and you only need launch/log checks, retry with INSTALL_APK=0." >&2
+      exit 1
+    fi
+  fi
+fi
+
+if [ "$FORCE_STOP" = "1" ]; then
+  echo ">>> force-stop $PACKAGE"
+  "${ADB[@]}" shell am force-stop "$PACKAGE" || true
+fi
+
+echo ">>> clear logcat"
+"${ADB[@]}" logcat -c
+
+if [ "$LAUNCH_APP" = "1" ]; then
+  echo ">>> launch $PACKAGE/$ACTIVITY"
+  "${ADB[@]}" shell am start -n "$PACKAGE/$ACTIVITY" > "$OUT_DIR/am-start.txt"
+fi
+
+echo ">>> wait ${WAIT_SECS}s"
+sleep "$WAIT_SECS"
+
+PID="$("${ADB[@]}" shell pidof "$PACKAGE" | tr -d '\r' || true)"
+if [ -z "$PID" ]; then
+  "${ADB[@]}" logcat -d > "$OUT_DIR/logcat.txt" || true
+  echo "app process is not running after launch: $PACKAGE" >&2
+  echo "logcat saved to $OUT_DIR/logcat.txt" >&2
+  exit 1
+fi
+echo "$PID" > "$OUT_DIR/pid.txt"
+
+if [ "$CAPTURE_SCREENSHOT" = "1" ]; then
+  echo ">>> capture screenshot"
+  "${ADB[@]}" shell screencap -p "$REMOTE_SCREENSHOT"
+  "${ADB[@]}" pull "$REMOTE_SCREENSHOT" "$OUT_DIR/launch.png" >/dev/null
+  "${ADB[@]}" shell rm -f "$REMOTE_SCREENSHOT" >/dev/null 2>&1 || true
+fi
+
+echo ">>> capture logcat"
+"${ADB[@]}" logcat -d > "$OUT_DIR/logcat.txt"
+grep -iE "panic|fatal|jni|native crash|\bANR\b|exception|error|warn|keystore|safe_area" "$OUT_DIR/logcat.txt" > "$OUT_DIR/log-summary.txt" || true
+"${ADB[@]}" shell df -h /data > "$OUT_DIR/df-data-after.txt" 2>&1 || true
+
+# Fatal patterns only. Avoid matching generic "error" because Android logs are
+# noisy and many non-fatal framework lines contain that word.
+if grep -iE "fatal exception|jni detected error|native crash|signal [0-9]+|ANR in|Application Not Responding|Input dispatching timed out|thread exiting with uncaught exception|panicked at" "$OUT_DIR/logcat.txt"; then
+  echo "Android smoke test found fatal log output" >&2
+  echo "Artifacts saved in $OUT_DIR" >&2
+  exit 1
+fi
+
+echo ">>> Android smoke test passed"
+echo "Artifacts saved in $OUT_DIR"

scripts/build_android_apk.sh

@@ -6,11 +6,15 @@
 # ndk-build crate that we couldn't isolate; running each Android toolchain
 # step explicitly gives us a debuggable pipeline.
 #
-# Required environment:
+# Environment:
-#   ANDROID_HOME            Path to Android SDK root
+#   ANDROID_HOME            Path to Android SDK root. If unset, common SDK
-#   ANDROID_NDK_HOME        Path to the specific NDK version
+#                           locations such as ~/Android/Sdk are tried.
-#   BUILD_TOOLS_VERSION     e.g. "34.0.0"
+#   ANDROID_NDK_HOME        Path to the specific NDK version. If unset, the
-#   PLATFORM                e.g. "android-34"
+#                           newest $ANDROID_HOME/ndk/* directory is used.
+#   BUILD_TOOLS_VERSION     e.g. "34.0.0". If unset, newest installed build-tools
+#                           version is used.
+#   PLATFORM                e.g. "android-34". If unset, newest installed
+#                           $ANDROID_HOME/platforms/android-* platform is used.
 #
 # Optional environment:
 #   PROFILE                 "debug" (default) | "release"
@@ -19,7 +23,8 @@
 #                           fit the runner's disk budget — a full three-ABI
 #                           debug build can exceed 25 GB of target/ output.
 #   APK_OUT                 Output APK path (default: target/$PROFILE/apk/ferrous-solitaire.apk)
-#   KEYSTORE                Path to keystore for signing (default: generates a debug keystore)
+#   STRIP_NATIVE_LIBS       1 to strip .so files before packaging (default: 1)
+#   KEYSTORE                Path to keystore for signing (default: target/android/debug.keystore)
 #   KEYSTORE_PASS           Keystore password (default: "android" for the generated debug keystore)
 #   KEY_ALIAS               Key alias (default: "androiddebugkey")
 #   KEY_PASS                Key password (default: same as KEYSTORE_PASS)
@@ -28,18 +33,63 @@
 #   $APK_OUT                Signed, zipaligned APK
 set -euo pipefail
 
-: "${ANDROID_HOME:?ANDROID_HOME must be set}"
+infer_latest_dir_name() {
-: "${ANDROID_NDK_HOME:?ANDROID_NDK_HOME must be set}"
+  local pattern="$1"
-: "${BUILD_TOOLS_VERSION:?BUILD_TOOLS_VERSION must be set}"
+  local latest=""
-: "${PLATFORM:?PLATFORM must be set (e.g. android-34)}"
+  shopt -s nullglob
+  local dirs=( $pattern )
+  shopt -u nullglob
+  if [ ${#dirs[@]} -gt 0 ]; then
+    latest="$(printf '%s\n' "${dirs[@]}" | sort -V | tail -n 1)"
+    basename "$latest"
+  fi
+}
+
+if [ -z "${ANDROID_HOME:-}" ]; then
+  for candidate in "$HOME/Android/Sdk" "$HOME/Library/Android/sdk" "/opt/android-sdk" "/usr/lib/android-sdk"; do
+    if [ -d "$candidate" ]; then
+      ANDROID_HOME="$candidate"
+      export ANDROID_HOME
+      break
+    fi
+  done
+fi
+: "${ANDROID_HOME:?ANDROID_HOME must be set or discoverable under a common SDK path}"
+
+if [ -z "${ANDROID_NDK_HOME:-}" ]; then
+  NDK_VERSION="$(infer_latest_dir_name "$ANDROID_HOME/ndk/*")"
+  if [ -n "$NDK_VERSION" ]; then
+    ANDROID_NDK_HOME="$ANDROID_HOME/ndk/$NDK_VERSION"
+    export ANDROID_NDK_HOME
+  fi
+fi
+: "${ANDROID_NDK_HOME:?ANDROID_NDK_HOME must be set or discoverable under ANDROID_HOME/ndk}"
+
+if [ -z "${BUILD_TOOLS_VERSION:-}" ]; then
+  BUILD_TOOLS_VERSION="$(infer_latest_dir_name "$ANDROID_HOME/build-tools/*")"
+  export BUILD_TOOLS_VERSION
+fi
+: "${BUILD_TOOLS_VERSION:?BUILD_TOOLS_VERSION must be set or discoverable under ANDROID_HOME/build-tools}"
+
+if [ -z "${PLATFORM:-}" ]; then
+  PLATFORM="$(infer_latest_dir_name "$ANDROID_HOME/platforms/android-*")"
+  export PLATFORM
+fi
+: "${PLATFORM:?PLATFORM must be set or discoverable under ANDROID_HOME/platforms}"
 
 PROFILE="${PROFILE:-debug}"
 ABIS="${ABIS:-arm64-v8a armeabi-v7a x86_64}"
 APK_OUT="${APK_OUT:-target/${PROFILE}/apk/ferrous-solitaire.apk}"
+STRIP_NATIVE_LIBS="${STRIP_NATIVE_LIBS:-1}"
 
 REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
 cd "$REPO_ROOT"
 
+echo ">>> Android SDK: $ANDROID_HOME"
+echo ">>> Android NDK: $ANDROID_NDK_HOME"
+echo ">>> Build tools: $BUILD_TOOLS_VERSION"
+echo ">>> Platform: $PLATFORM"
+
 BT="$ANDROID_HOME/build-tools/$BUILD_TOOLS_VERSION"
 PLATFORM_JAR="$ANDROID_HOME/platforms/$PLATFORM/android.jar"
 MANIFEST="solitaire_app/android/AndroidManifest.xml"
@@ -69,6 +119,24 @@ fi
 echo ">>> cargo ndk ${CARGO_NDK_ARGS[*]}"
 cargo ndk "${CARGO_NDK_ARGS[@]}"
 
+if [ "$STRIP_NATIVE_LIBS" = "1" ]; then
+  LLVM_STRIP=""
+  shopt -s nullglob
+  STRIP_CANDIDATES=( "$ANDROID_NDK_HOME"/toolchains/llvm/prebuilt/*/bin/llvm-strip )
+  shopt -u nullglob
+  if [ ${#STRIP_CANDIDATES[@]} -gt 0 ]; then
+    LLVM_STRIP="${STRIP_CANDIDATES[0]}"
+  fi
+  if [ -z "$LLVM_STRIP" ]; then
+    echo "llvm-strip not found under ANDROID_NDK_HOME; native libraries will remain unstripped" >&2
+  else
+    echo ">>> strip native libraries with $LLVM_STRIP"
+    find "$STAGING/lib" -name '*.so' -print0 | while IFS= read -r -d '' so; do
+      "$LLVM_STRIP" --strip-debug "$so"
+    done
+  fi
+fi
+
 # --- 2. compile + link resources and manifest ------------------------------
 if [ -d "$RES_DIR" ]; then
   echo ">>> aapt2 compile resources"
@@ -120,11 +188,15 @@ rm -f "$STAGING/app-unsigned.apk"
 
 # --- 5. sign ---------------------------------------------------------------
 if [ -z "${KEYSTORE:-}" ]; then
-  # Generate a deterministic debug keystore on the fly.
+  KEYSTORE="target/android/debug.keystore"
-  KEYSTORE="$STAGING/debug.keystore"
+fi
+
 KEYSTORE_PASS="${KEYSTORE_PASS:-android}"
 KEY_ALIAS="${KEY_ALIAS:-androiddebugkey}"
 KEY_PASS="${KEY_PASS:-$KEYSTORE_PASS}"
+
+if [ ! -f "$KEYSTORE" ]; then
+  mkdir -p "$(dirname "$KEYSTORE")"
   echo ">>> generating debug keystore at $KEYSTORE"
   keytool -genkeypair -v \
     -keystore "$KEYSTORE" \
@@ -141,15 +213,35 @@ KEY_PASS="${KEY_PASS:-$KEYSTORE_PASS}"
 
 mkdir -p "$(dirname "$APK_OUT")"
 echo ">>> apksigner sign -> $APK_OUT"
+# Sign the schemes explicitly instead of relying on apksigner's auto behaviour.
+# Left to "auto", this pipeline produced an APK carrying invalid v1 (JAR)
+# signature files (META-INF/*.SF/.RSA present but failing v1 verification).
+# Android installs it fine via v2/v3, but Obtainium parses the APK's legacy v1
+# certificate at install time, gets an empty cert list, and crashes with
+# "RangeError (length): Invalid value: valid value range is empty: 0".
+# minSdk is 26 (solitaire_app/android/AndroidManifest.xml), so v1/JAR signing is
+# not needed at all — disable it and ship a clean v2+v3 signature, matching what
+# modern Android tooling produces for minSdk >= 24.
 "$BT/apksigner" sign \
   --ks "$KEYSTORE" \
   --ks-pass "pass:$KEYSTORE_PASS" \
   --ks-key-alias "$KEY_ALIAS" \
   --key-pass "pass:$KEY_PASS" \
+  --min-sdk-version 26 \
+  --v1-signing-enabled false \
+  --v2-signing-enabled true \
+  --v3-signing-enabled true \
   --out "$APK_OUT" \
   "$STAGING/app-aligned.apk"
 
 echo ">>> verify"
-"$BT/apksigner" verify --verbose "$APK_OUT"
+"$BT/apksigner" verify --min-sdk-version 26 --verbose "$APK_OUT"
+
+# Guard: no leftover v1/JAR signature files may remain — their presence (valid or
+# not) is what tripped Obtainium. Fail the build if any slipped through.
+if unzip -l "$APK_OUT" 2>/dev/null | grep -qiE 'META-INF/.*\.(SF|RSA|DSA|EC)$'; then
+  echo "ERROR: APK still contains v1/JAR signature files; expected v2+v3 only" >&2
+  exit 1
+fi
 
 echo ">>> done: $APK_OUT"

scripts/update_quaternions_deps.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+# Update Quaternions registry dependencies and run the full safety gate.
+#
+# Usage:
+#   scripts/update_quaternions_deps.sh <klondike_version> <card_game_version>
+#
+# Example:
+#   scripts/update_quaternions_deps.sh 0.3.1 0.4.1
+#
+# This script updates Cargo.lock to the requested versions (within the semver
+# ranges already declared in Cargo.toml), then runs the project's required
+# verification steps plus deterministic replay checks.
+set -euo pipefail
+
+if [ "$#" -ne 2 ]; then
+  echo "usage: $0 <klondike_version> <card_game_version>"
+  exit 2
+fi
+
+KLONDIKE_VERSION="$1"
+CARD_GAME_VERSION="$2"
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+
+cd "$REPO_ROOT"
+
+echo ">>> Quaternions registry:"
+echo "    https://git.aleshym.co/api/packages/Quaternions/cargo/"
+echo
+echo ">>> Review upstream release notes / changelogs before proceeding:"
+echo "    - https://git.aleshym.co/Quaternions/card_game"
+echo "    - https://git.aleshym.co/Quaternions/klondike"
+echo
+
+echo ">>> Updating lockfile to klondike=$KLONDIKE_VERSION card_game=$CARD_GAME_VERSION"
+cargo update -p klondike --precise "$KLONDIKE_VERSION"
+cargo update -p card_game --precise "$CARD_GAME_VERSION"
+
+echo ">>> Verifying dependency graph"
+cargo tree -p solitaire_core --depth 2 | cat
+
+echo ">>> Running workspace tests"
+cargo test --workspace
+
+echo ">>> Running workspace clippy"
+cargo clippy --workspace -- -D warnings
+
+echo ">>> Running deterministic replay / debug-api smoke checks"
+cargo test -p solitaire_wasm debug_snapshot_exposes_replayable_seed_and_history -- --exact
+cargo test -p solitaire_wasm debug_api_autonomous_seed_batch_smoke -- --exact
+
+echo ">>> Quaternions dependency upgrade gate passed"

scripts/watch_deploy.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+# Live-watch the Gitea Actions deploy pipeline for Ferrous Solitaire.
+#
+# Polls recent workflow runs and prints a compact status block each cycle.
+# Stops when the newest docker-build (the deploy) has completed and no
+# web-wasm-rebuild is still pending — i.e. the full fix is live.
+#
+# Usage:  ./scripts/watch_deploy.sh [interval_seconds]
+#   token is read from ~/.config/tea/config.yml (never printed).
+set -uo pipefail
+
+REPO="funman300/Ferrous-Solitaire"
+BASE="https://git.aleshym.co/api/v1/repos/${REPO}"
+INTERVAL="${1:-20}"
+CFG="${HOME}/.config/tea/config.yml"
+
+TOKEN="$(grep -E '^[[:space:]]*token:' "$CFG" | head -1 | sed -E 's/.*token:[[:space:]]*//' | tr -d '"'\'' ')"
+[ -z "$TOKEN" ] && { echo "error: no token in $CFG" >&2; exit 1; }
+
+echo "── watching ${REPO} deploy (poll ${INTERVAL}s, Ctrl-C to stop) ──"
+
+while :; do
+  json="$(curl -s --max-time 20 -H "Authorization: token ${TOKEN}" "${BASE}/actions/runs?limit=6")"
+  # Print rows + emit the deploy state on the last line (parsed below).
+  # JSON is passed via env var because `python3 -` reads its program from the
+  # heredoc on stdin, so stdin can't also carry the data.
+  out="$(JSON_DATA="$json" python3 - <<'PY'
+import os, sys, json, datetime
+now = datetime.datetime.now().strftime("%H:%M:%S")
+raw = os.environ.get("JSON_DATA", "").strip()
+try:
+    d = json.loads(raw)
+except Exception:
+    print("[%s] (api unavailable, retrying)" % now)
+    print("STATE=DEPLOYING")
+    sys.exit(0)
+runs = d.get("workflow_runs", [])[:6]
+icons = {("completed","success"):"OK  ", ("completed","failure"):"FAIL",
+         ("completed","cancelled"):"CXL "}
+def ic(s, c):
+    if s == "queued": return "queue"
+    if s == "in_progress": return "run.."
+    return icons.get((s, c), s or "?")
+print("[%s]" % datetime.datetime.now().strftime("%H:%M:%S"))
+for r in runs:
+    wf = str(r.get("path","")).split("@")[0].split("/")[-1].replace(".yml","")
+    print("   %-5s %-5s %-7s %-18s %s/%s" % (
+        ic(r.get("status"), r.get("conclusion")),
+        r.get("id"), str(r.get("head_sha"))[:7], wf[:18],
+        r.get("status"), r.get("conclusion")))
+db = [r for r in runs if "docker-build" in str(r.get("path"))]
+wr_pending = any(r.get("status") != "completed" for r in runs if "web-wasm-rebuild" in str(r.get("path")))
+top = db[0] if db else None
+live = bool(top and top.get("status")=="completed" and top.get("conclusion")=="success" and not wr_pending)
+print("STATE=%s" % ("LIVE" if live else ("WAIT_WASM" if wr_pending else "DEPLOYING")))
+PY
+)"
+  echo "$out" | grep -v '^STATE='
+  if echo "$out" | grep -q '^STATE=LIVE'; then
+    echo ""
+    echo "DEPLOY LIVE — newest docker-build succeeded, no wasm rebuild pending."
+    echo "   Test: https://klondike.aleshym.co/play?v=${RANDOM}"
+    break
+  fi
+  sleep "$INTERVAL"
+done

solitaire_app/Cargo.toml

@@ -22,6 +22,13 @@ bevy             = { workspace = true }
 solitaire_engine = { workspace = true }
 solitaire_data   = { workspace = true }
 
+# Android-only: the entry point reconstructs the raw `JavaVM` / activity
+# handles and registers the safe `solitaire_data::android_jni` bridge. This
+# is the one crate in the workspace that performs `unsafe` FFI, so it is also
+# the only one that depends on `jni` directly at the app layer.
+[target.'cfg(target_os = "android")'.dependencies]
+jni = { workspace = true }
+
 # Desktop-only deps. `keyring`'s default-store init only matters on
 # platforms with a real keychain backend (Linux Secret Service,
 # macOS Keychain, Windows Credential Store), and its transitive
@@ -99,3 +106,18 @@ icon = "@mipmap/ic_launcher"
 # in portrait orientation. Remove (or add a landscape layout) before
 # enabling auto-rotate.
 orientation = "portrait"
+
+# `solitaire_app` is the one crate that cannot inherit the workspace
+# `forbid(unsafe_code)`: as the Android cdylib it must export the
+# `#[unsafe(no_mangle)]` entry point and reconstruct the raw JNI handles
+# there (a `no_mangle` symbol cannot live in a dependency rlib). It mirrors
+# the workspace lints but at `deny`, so the two `#[allow(unsafe_code)]`
+# scopes in the Android entry point are the only unsafe in the whole tree.
+[lints.rust]
+unsafe_code = "deny"
+single_use_lifetimes = "warn"
+trivial_casts = "warn"
+unused_lifetimes = "warn"
+unused_qualifications = "warn"
+variant_size_differences = "warn"
+unexpected_cfgs = "warn"

solitaire_app/src/lib.rs

@@ -25,7 +25,10 @@ use bevy::window::{MonitorSelection, PresentMode, WindowPosition};
 use bevy::winit::WinitWindows;
 #[cfg(target_os = "android")]
 use bevy::winit::{UpdateMode, WinitSettings};
-use solitaire_data::{Settings, load_settings_from, provider_for_backend, settings_file_path};
+use solitaire_data::{
+    Settings, cleanup_orphaned_tmp_files, load_settings_from, provider_for_backend,
+    settings_file_path,
+};
 use solitaire_engine::{CoreGamePlugin, SyncProvider, register_theme_asset_sources};
 
 fn load_settings() -> Settings {
@@ -49,6 +52,12 @@ pub fn run() {
     // and any debugger attached still sees the panic).
     install_crash_log_hook();
 
+    // Remove any *.tmp files left behind by a crash between an atomic write
+    // and its rename.  Safe to call unconditionally — missing data dir is a
+    // no-op.  Must run before GamePlugin loads saved state so orphaned files
+    // don't accumulate across launches.
+    let _ = cleanup_orphaned_tmp_files();
+
     // Initialise the platform keyring store before any token operations.
     // On Linux this uses the Secret Service (GNOME Keyring / KWallet); on
     // macOS it uses the Keychain; on Windows it uses the Credential store.
@@ -56,10 +65,9 @@ pub fn run() {
     // operations will fail gracefully with TokenError::KeychainUnavailable.
     //
     // Android: `keyring` isn't compiled in (its `rpassword` transitive
-    // pulls a libc symbol Android's bionic doesn't expose). `auth_tokens`
+    // pulls a libc symbol Android's bionic doesn't expose). The Android
-    // ships an Android stub that returns KeychainUnavailable for every
+    // auth-token path uses Android Keystore via JNI; `android_main` passes
-    // call — the runtime behaviour is "session login required each launch"
+    // the process JavaVM pointer into `solitaire_data` before `run()`.
-    // until we wire Android Keystore via JNI in the Phase-Android round.
     #[cfg(not(target_os = "android"))]
     if let Err(e) = keyring::use_native_store(true) {
         eprintln!(
@@ -136,7 +144,7 @@ fn build_app_with_settings(
                     // Android windows always fill the screen; max_width/max_height
                     // default to 0.0, which panics Bevy's clamp when min > max.
                     #[cfg(not(target_os = "android"))]
-                    resize_constraints: bevy::window::WindowResizeConstraints {
+                    resize_constraints: WindowResizeConstraints {
                         min_width: 800.0,
                         min_height: 600.0,
                         ..default()
@@ -158,7 +166,7 @@ fn build_app_with_settings(
             // default makes it walk *out* of the APK's assets root and
             // all loads fail silently — which is what produced the
             // solid-red card-back fallback in the v0.22.3 screenshot.
-            .set(bevy::asset::AssetPlugin {
+            .set(AssetPlugin {
                 #[cfg(not(target_os = "android"))]
                 file_path: "../assets".to_string(),
                 ..default()
@@ -172,13 +180,16 @@ fn build_app_with_settings(
     // a 1-second ceiling when the app is backgrounded cuts wake-up frequency
     // from ~60 Hz to ≤1 Hz, dramatically reducing background battery drain.
     //
-    // The focused mode stays Continuous so that card-slide animations remain
+    // focused_mode uses reactive_low_power(100 ms) so the CPU only wakes when
-    // smooth. PresentMode::AutoVsync (set above) keeps the GPU capped at the
+    // an event arrives (touch, resize, etc.) or an animation system writes
-    // display refresh rate (~60 Hz) when foregrounded, which already prevents
+    // RequestRedraw. The 100 ms ceiling is a fallback that ensures the game
-    // the GPU from spinning at 200+ fps between vsync intervals.
+    // timer ticks at least 10×/s even with no input, while keeping the GPU
+    // completely idle between frames when the board is static.
+    // PresentMode::AutoVsync (set above) still caps the GPU at the display
+    // refresh rate when frames do render.
     #[cfg(target_os = "android")]
     app.insert_resource(WinitSettings {
-        focused_mode: UpdateMode::Continuous,
+        focused_mode: UpdateMode::reactive_low_power(std::time::Duration::from_millis(100)),
         unfocused_mode: UpdateMode::reactive_low_power(std::time::Duration::from_secs(1)),
     });
 
@@ -352,12 +363,57 @@ fn set_window_icon(
 /// works on a function named `main`; our shared entry point is `run`, so
 /// we emit the equivalent expansion manually.
 #[cfg(target_os = "android")]
+#[allow(unsafe_code)]
 #[unsafe(no_mangle)]
 fn android_main(android_app: bevy::android::android_activity::AndroidApp) {
+    if let Err(e) = init_android_jni(&android_app) {
+        eprintln!("warn: could not initialise Android JNI bridge ({e})");
+    }
     let _ = bevy::android::ANDROID_APP.set(android_app);
     run();
 }
 
+/// Reconstructs the raw `JavaVM` / `NativeActivity` handles handed over by the
+/// Android runtime and registers safe wrappers with `solitaire_data`.
+///
+/// This is the *only* place in the workspace that performs `unsafe` FFI handle
+/// reconstruction. Every other crate consumes the safe
+/// [`solitaire_data::android_jni`] bridge and stays `forbid(unsafe_code)`;
+/// `solitaire_app` opts down to `deny` with a narrowly scoped allow on this
+/// function and the `#[unsafe(no_mangle)]` entry point above.
+#[cfg(target_os = "android")]
+#[allow(unsafe_code)]
+fn init_android_jni(
+    android_app: &bevy::android::android_activity::AndroidApp,
+) -> Result<(), String> {
+    use jni::JavaVM;
+    use jni::objects::JObject;
+
+    let vm_ptr = android_app.vm_as_ptr();
+    if vm_ptr.is_null() {
+        return Err("JavaVM pointer is null".into());
+    }
+    // SAFETY: `vm_as_ptr()` returns the process-wide JavaVM* established by the
+    // Android runtime; it is valid for the lifetime of the process.
+    let vm = unsafe { JavaVM::from_raw(vm_ptr.cast()) }.map_err(|e| format!("JavaVM: {e}"))?;
+
+    let env = vm
+        .attach_current_thread_permanently()
+        .map_err(|e| format!("attach_current_thread: {e}"))?;
+
+    // SAFETY: `activity_as_ptr()` returns the NativeActivity jobject pointer,
+    // valid for the lifetime of the process. Promote it to a global reference
+    // so the safe bridge can hand it to any thread.
+    let activity = unsafe { JObject::from_raw(android_app.activity_as_ptr().cast()) };
+    let activity_ref = env
+        .new_global_ref(&activity)
+        .map_err(|e| format!("activity global ref: {e}"))?;
+
+    solitaire_data::android_jni::set_jvm(vm);
+    solitaire_data::android_jni::set_activity(activity_ref);
+    Ok(())
+}
+
 /// Wraps the default panic hook with one that also appends a crash log
 /// to `<data_dir>/crash.log` (next to `settings.json`). The default hook
 /// still runs afterwards, so stderr output and debugger integration are

solitaire_assetgen/Cargo.toml

@@ -30,3 +30,6 @@ path = "src/bin/gen_seeds.rs"
 [[bin]]
 name = "gen_difficulty_seeds"
 path = "src/bin/gen_difficulty_seeds.rs"
+
+[lints]
+workspace = true

solitaire_assetgen/src/bin/gen_difficulty_seeds.rs

@@ -2,10 +2,10 @@
 //! `HARD_SEEDS`, `EXPERT_SEEDS`, and `GRANDMASTER_SEEDS` in
 //! `solitaire_data/src/difficulty_seeds.rs`.
 //!
-//! A seed's tier is determined by the **smallest** `SolverConfig` budget that
+//! A seed's tier is determined by the **smallest** solve budget at which it is
-//! returns `SolverResult::Winnable`. Seeds that are `Unwinnable` at any budget
+//! proven winnable (`Ok(Some(_))`). Seeds proven dead (`Ok(None)`) at any budget
-//! are discarded; `Inconclusive` at all budgets are also discarded (we only emit
+//! are discarded; seeds inconclusive (`Err`) at all budgets are also discarded
-//! provably-winnable seeds).
+//! (we only emit provably-winnable seeds).
 //!
 //! # Usage
 //!
@@ -19,12 +19,12 @@
 //!   --per-tier  Seeds to emit per tier (default 40)
 //!   --help      Print this message
 
-use solitaire_core::game_state::DrawMode;
+use solitaire_core::DrawStockConfig;
-use solitaire_core::solver::{SolverConfig, SolverResult, try_solve};
+use solitaire_core::game_state::GameState;
 
 // Budget boundaries defining each tier. A seed belongs to the lowest tier
 // whose budget proves it Winnable.
-const BUDGETS: &[(&str, u64, usize)] = &[
+const BUDGETS: &[(&str, u64, u64)] = &[
     ("Easy", 1_000, 1_000),
     ("Medium", 5_000, 5_000),
     ("Hard", 25_000, 25_000),
@@ -74,7 +74,7 @@ fn main() {
         std::process::exit(1);
     }
 
-    let draw_mode = DrawMode::DrawOne;
+    let draw_mode = DrawStockConfig::DrawOne;
     let num_tiers = BUDGETS.len();
     let mut buckets: Vec<Vec<u64>> = vec![Vec::with_capacity(per_tier); num_tiers];
     let mut tried: u64 = 0;
@@ -99,12 +99,8 @@ fn main() {
             if buckets[i].len() >= per_tier {
                 continue;
             }
-            let cfg = SolverConfig {
+            match GameState::solve_fresh_deal(seed, draw_mode, move_budget, state_budget) {
-                move_budget,
+                Ok(Some(_)) => {
-                state_budget,
-            };
-            match try_solve(seed, draw_mode, &cfg) {
-                SolverResult::Winnable => {
                     buckets[i].push(seed);
                     eprintln!(
                         "  [{name}  {:>3}/{}]  0x{seed:016X}  (tried {tried})",
@@ -113,13 +109,13 @@ fn main() {
                     );
                     break 'tier; // assign to the cheapest tier that proves it winnable
                 }
-                SolverResult::Unwinnable => {
+                Ok(None) => {
                     // Definitely unsolvable — skip all remaining tiers.
                     break 'tier;
                 }
-                SolverResult::Inconclusive => {
+                Err(_) => {
                     // Budget exhausted without proof — try the next larger tier.
-                    // If this is the last tier, the seed is discarded (Inconclusive
+                    // If this is the last tier, the seed is discarded (inconclusive
                     // at max budget means "probably but not provably winnable").
                     if i == num_tiers - 1 {
                         break 'tier;

solitaire_assetgen/src/bin/gen_seeds.rs

@@ -1,7 +1,7 @@
 //! Generate provably-winnable Klondike seeds for `CHALLENGE_SEEDS`.
 //!
 //! Walks seeds incrementally from `--start`, calls the solver on each, and
-//! collects only those that return `SolverResult::Winnable` (Inconclusive is
+//! collects only those proven winnable (`Ok(Some(_))`; inconclusive is
 //! rejected — the curated list wants proof). Prints Rust source suitable for
 //! pasting into `solitaire_data/src/challenge.rs`.
 //!
@@ -17,8 +17,9 @@
 //!   --count  Number of Winnable seeds to emit (default 75)
 //!   --help   Print this message
 
-use solitaire_core::game_state::DrawMode;
+use solitaire_core::DrawStockConfig;
-use solitaire_core::solver::{SolverConfig, SolverResult, try_solve};
+use solitaire_core::game_state::GameState;
+use solitaire_core::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET};
 
 fn main() {
     let mut args = std::env::args().skip(1).peekable();
@@ -67,8 +68,7 @@ fn main() {
         std::process::exit(1);
     }
 
-    let cfg = SolverConfig::default();
+    let draw_mode = DrawStockConfig::DrawOne;
-    let draw_mode = DrawMode::DrawOne;
     let mut found: Vec<u64> = Vec::with_capacity(count);
     let mut tried: u64 = 0;
     let mut seed = start;
@@ -77,7 +77,15 @@ fn main() {
 
     while found.len() < count {
         tried += 1;
-        if matches!(try_solve(seed, draw_mode, &cfg), SolverResult::Winnable) {
+        if matches!(
+            GameState::solve_fresh_deal(
+                seed,
+                draw_mode,
+                DEFAULT_SOLVE_MOVES_BUDGET,
+                DEFAULT_SOLVE_STATES_BUDGET
+            ),
+            Ok(Some(_))
+        ) {
             found.push(seed);
             eprintln!(
                 "  [{:>3}/{}]  0x{:016X}  ({} tried so far)",

solitaire_core/Cargo.toml

@@ -4,7 +4,18 @@ version.workspace = true
 license.workspace = true
 edition.workspace = true
 
+[features]
+default = []
+test-support = []
+
+[dev-dependencies]
+proptest = "1"
+
 [dependencies]
 serde     = { workspace = true }
 thiserror = { workspace = true }
-rand      = { workspace = true }
+klondike  = { workspace = true }
+card_game = { workspace = true }
+
+[lints]
+workspace = true

solitaire_core/src/card.rs

@@ -1,169 +0,0 @@
-use serde::{Deserialize, Serialize};
-
-/// Card suit.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub enum Suit {
-    Clubs,
-    Diamonds,
-    Hearts,
-    Spades,
-}
-
-impl Suit {
-    /// All four suits in declaration order.
-    pub const SUITS: [Self; 4] = [Self::Clubs, Self::Diamonds, Self::Hearts, Self::Spades];
-
-    /// Returns `true` for red suits (Diamonds, Hearts).
-    pub fn is_red(self) -> bool {
-        matches!(self, Suit::Diamonds | Suit::Hearts)
-    }
-
-    /// Returns `true` for black suits (Clubs, Spades).
-    pub fn is_black(self) -> bool {
-        !self.is_red()
-    }
-}
-
-/// Card rank, Ace through King.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize)]
-pub enum Rank {
-    Ace = 1,
-    Two = 2,
-    Three = 3,
-    Four = 4,
-    Five = 5,
-    Six = 6,
-    Seven = 7,
-    Eight = 8,
-    Nine = 9,
-    Ten = 10,
-    Jack = 11,
-    Queen = 12,
-    King = 13,
-}
-
-impl Rank {
-    /// All thirteen ranks in ascending order.
-    pub const RANKS: [Self; 13] = [
-        Self::Ace,
-        Self::Two,
-        Self::Three,
-        Self::Four,
-        Self::Five,
-        Self::Six,
-        Self::Seven,
-        Self::Eight,
-        Self::Nine,
-        Self::Ten,
-        Self::Jack,
-        Self::Queen,
-        Self::King,
-    ];
-
-    /// Numeric value: Ace = 1, King = 13.
-    pub fn value(self) -> u8 {
-        self as u8
-    }
-
-    const fn new(n: u8) -> Option<Self> {
-        match n {
-            1 => Some(Self::Ace),
-            2 => Some(Self::Two),
-            3 => Some(Self::Three),
-            4 => Some(Self::Four),
-            5 => Some(Self::Five),
-            6 => Some(Self::Six),
-            7 => Some(Self::Seven),
-            8 => Some(Self::Eight),
-            9 => Some(Self::Nine),
-            10 => Some(Self::Ten),
-            11 => Some(Self::Jack),
-            12 => Some(Self::Queen),
-            13 => Some(Self::King),
-            _ => None,
-        }
-    }
-
-    /// Returns the rank `n` steps above `self`, or `None` if it would exceed King.
-    pub const fn checked_add(self, n: u8) -> Option<Self> {
-        Self::new((self as u8).saturating_add(n))
-    }
-
-    /// Returns the rank `n` steps below `self`, or `None` if it would go below Ace.
-    pub const fn checked_sub(self, n: u8) -> Option<Self> {
-        match (self as u8).checked_sub(n) {
-            Some(v) => Self::new(v),
-            None => None,
-        }
-    }
-}
-
-/// A single playing card.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct Card {
-    /// Unique identifier for this card within the deal. Stable across moves and undo.
-    pub id: u32,
-    /// The card's suit (Clubs, Diamonds, Hearts, Spades).
-    pub suit: Suit,
-    /// The card's rank (Ace through King).
-    pub rank: Rank,
-    /// Whether the card is visible to the player. Face-down cards may not be moved.
-    pub face_up: bool,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn rank_values_are_sequential() {
-        for (i, r) in Rank::RANKS.iter().enumerate() {
-            assert_eq!(r.value(), (i + 1) as u8);
-        }
-    }
-
-    #[test]
-    fn rank_as_u8_matches_value() {
-        for r in Rank::RANKS {
-            assert_eq!(r as u8, r.value());
-        }
-    }
-
-    #[test]
-    fn rank_checked_add_boundary() {
-        assert_eq!(Rank::King.checked_add(1), None);
-        assert_eq!(Rank::Queen.checked_add(1), Some(Rank::King));
-        assert_eq!(Rank::Ace.checked_add(1), Some(Rank::Two));
-        assert_eq!(Rank::Five.checked_add(3), Some(Rank::Eight));
-    }
-
-    #[test]
-    fn rank_checked_sub_boundary() {
-        assert_eq!(Rank::Ace.checked_sub(1), None);
-        assert_eq!(Rank::Two.checked_sub(1), Some(Rank::Ace));
-        assert_eq!(Rank::King.checked_sub(1), Some(Rank::Queen));
-        assert_eq!(Rank::Five.checked_sub(3), Some(Rank::Two));
-    }
-
-    #[test]
-    fn suit_suits_contains_all_four() {
-        assert_eq!(Suit::SUITS.len(), 4);
-        assert!(Suit::SUITS.contains(&Suit::Clubs));
-        assert!(Suit::SUITS.contains(&Suit::Diamonds));
-        assert!(Suit::SUITS.contains(&Suit::Hearts));
-        assert!(Suit::SUITS.contains(&Suit::Spades));
-    }
-
-    #[test]
-    fn suit_red_and_black_are_complementary() {
-        for suit in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades] {
-            assert_ne!(
-                suit.is_red(),
-                suit.is_black(),
-                "{suit:?} must be exactly one of red/black"
-            );
-        }
-        assert!(Suit::Diamonds.is_red() && Suit::Hearts.is_red());
-        assert!(Suit::Clubs.is_black() && Suit::Spades.is_black());
-    }
-}

solitaire_core/src/deck.rs

@@ -1,193 +0,0 @@
-use crate::card::{Card, Rank, Suit};
-use crate::pile::{Pile, PileType};
-use rand::rngs::StdRng;
-use rand::{SeedableRng, seq::SliceRandom};
-
-const ALL_SUITS: [Suit; 4] = [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades];
-const ALL_RANKS: [Rank; 13] = [
-    Rank::Ace,
-    Rank::Two,
-    Rank::Three,
-    Rank::Four,
-    Rank::Five,
-    Rank::Six,
-    Rank::Seven,
-    Rank::Eight,
-    Rank::Nine,
-    Rank::Ten,
-    Rank::Jack,
-    Rank::Queen,
-    Rank::King,
-];
-
-/// A standard 52-card deck.
-pub struct Deck {
-    /// All 52 cards in the deck, in deal order.
-    pub cards: Vec<Card>,
-}
-
-impl Deck {
-    /// Creates an unshuffled deck with all 52 unique cards (id 0–51).
-    pub fn new() -> Self {
-        let mut cards = Vec::with_capacity(52);
-        let mut id = 0u32;
-        for &suit in &ALL_SUITS {
-            for &rank in &ALL_RANKS {
-                cards.push(Card {
-                    id,
-                    suit,
-                    rank,
-                    face_up: false,
-                });
-                id += 1;
-            }
-        }
-        Self { cards }
-    }
-
-    /// Shuffles the deck in-place using Fisher-Yates with a seeded `StdRng`.
-    /// The same seed always produces the same order on any platform.
-    pub fn shuffle(&mut self, seed: u64) {
-        let mut rng = StdRng::seed_from_u64(seed);
-        self.cards.shuffle(&mut rng);
-    }
-}
-
-impl Default for Deck {
-    fn default() -> Self {
-        Self::new()
-    }
-}
-
-/// Deals a standard Klondike layout from a pre-shuffled deck.
-///
-/// Returns 7 tableau piles and the remaining stock pile.
-/// Column `i` contains `i + 1` cards; only the top card is face-up.
-/// Stock receives the remaining 24 cards, all face-down.
-pub fn deal_klondike(deck: Deck) -> ([Pile; 7], Pile) {
-    debug_assert_eq!(
-        deck.cards.len(),
-        52,
-        "deal_klondike requires a full 52-card deck"
-    );
-    let mut tableau: [Pile; 7] = core::array::from_fn(|i| Pile::new(PileType::Tableau(i)));
-    // Safety: the debug_assert above documents the 52-card contract; index arithmetic is bounded.
-    let mut idx = 0usize;
-
-    for (col, pile) in tableau.iter_mut().enumerate() {
-        for row in 0..=col {
-            let mut card = deck.cards[idx].clone();
-            card.face_up = row == col;
-            pile.cards.push(card);
-            idx += 1;
-        }
-    }
-
-    let mut stock = Pile::new(PileType::Stock);
-    stock.cards.extend(deck.cards.into_iter().skip(idx));
-    (tableau, stock)
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn deck_new_has_52_cards() {
-        assert_eq!(Deck::new().cards.len(), 52);
-    }
-
-    #[test]
-    fn deck_new_has_unique_ids() {
-        let deck = Deck::new();
-        let mut ids: Vec<u32> = deck.cards.iter().map(|c| c.id).collect();
-        ids.sort_unstable();
-        ids.dedup();
-        assert_eq!(ids.len(), 52);
-    }
-
-    #[test]
-    fn deck_new_has_all_suits_and_ranks() {
-        let deck = Deck::new();
-        for suit in ALL_SUITS {
-            for rank in ALL_RANKS {
-                assert!(
-                    deck.cards.iter().any(|c| c.suit == suit && c.rank == rank),
-                    "missing {rank:?} {suit:?}"
-                );
-            }
-        }
-    }
-
-    #[test]
-    fn same_seed_produces_same_order() {
-        let mut d1 = Deck::new();
-        d1.shuffle(42);
-        let mut d2 = Deck::new();
-        d2.shuffle(42);
-        assert_eq!(d1.cards, d2.cards);
-    }
-
-    #[test]
-    fn different_seeds_produce_different_orders() {
-        let mut d1 = Deck::new();
-        d1.shuffle(1);
-        let mut d2 = Deck::new();
-        d2.shuffle(2);
-        assert_ne!(d1.cards, d2.cards);
-    }
-
-    #[test]
-    fn deal_klondike_correct_tableau_sizes() {
-        let mut deck = Deck::new();
-        deck.shuffle(0);
-        let (tableau, stock) = deal_klondike(deck);
-        for (i, pile) in tableau.iter().enumerate() {
-            assert_eq!(pile.cards.len(), i + 1, "col {i} wrong size");
-        }
-        assert_eq!(stock.cards.len(), 24);
-    }
-
-    #[test]
-    fn deal_klondike_top_cards_are_face_up() {
-        let mut deck = Deck::new();
-        deck.shuffle(0);
-        let (tableau, _) = deal_klondike(deck);
-        for pile in &tableau {
-            assert!(pile.cards.last().unwrap().face_up);
-        }
-    }
-
-    #[test]
-    fn deal_klondike_non_top_cards_are_face_down() {
-        let mut deck = Deck::new();
-        deck.shuffle(0);
-        let (tableau, _) = deal_klondike(deck);
-        for pile in &tableau {
-            for card in &pile.cards[..pile.cards.len().saturating_sub(1)] {
-                assert!(!card.face_up);
-            }
-        }
-    }
-
-    #[test]
-    fn deal_klondike_stock_is_face_down() {
-        let mut deck = Deck::new();
-        deck.shuffle(0);
-        let (_, stock) = deal_klondike(deck);
-        assert!(stock.cards.iter().all(|c| !c.face_up));
-    }
-
-    #[test]
-    fn deal_klondike_all_52_cards_present() {
-        let mut deck = Deck::new();
-        deck.shuffle(99);
-        let (tableau, stock) = deal_klondike(deck);
-        let mut ids: Vec<u32> = stock.cards.iter().map(|c| c.id).collect();
-        for pile in &tableau {
-            ids.extend(pile.cards.iter().map(|c| c.id));
-        }
-        ids.sort_unstable();
-        assert_eq!(ids, (0u32..52).collect::<Vec<_>>());
-    }
-}

solitaire_core/src/klondike_adapter.rs

@@ -0,0 +1,85 @@
+//! Adapter bridging `solitaire_core` types to the upstream `klondike` crate.
+//!
+//! [`KlondikeAdapter`] is a pure helper namespace for:
+//! - building [`KlondikeConfig`] from Ferrous settings
+//! - translating between local and upstream types
+//!
+//! Ferrous-specific scoring policy (the win-time bonus) lives in
+//! [`crate::scoring`], not here.
+//!
+//! All `From` / `TryFrom` conversions between `solitaire_core` product types and
+//! upstream `card_game` / `klondike` types live here so that the product modules
+//! (`card`, `pile`, etc.) remain free of upstream dependencies.
+
+use klondike::{
+    DrawStockConfig, Foundation, KlondikeConfig, MoveFromFoundationConfig, ScoringConfig,
+    SkipCards, Tableau,
+};
+
+/// Bridges `solitaire_core` game config to the upstream `klondike` crate.
+///
+/// This type is intentionally zero-sized: it does not carry mutable runtime
+/// state, and exists only as a namespace for configuration and conversion
+/// helpers.
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq)]
+pub struct KlondikeAdapter;
+
+impl KlondikeAdapter {
+    /// Build a [`KlondikeConfig`] from draw mode and foundation house-rule setting.
+    pub fn config_for(draw_mode: DrawStockConfig, take_from_foundation: bool) -> KlondikeConfig {
+        KlondikeConfig {
+            draw_stock: draw_mode,
+            move_from_foundation: if take_from_foundation {
+                MoveFromFoundationConfig::Allowed
+            } else {
+                MoveFromFoundationConfig::Disallowed
+            },
+            scoring: ScoringConfig::DEFAULT,
+        }
+    }
+}
+
+/// Convert a zero-based tableau index (0..=6) into [`Tableau`].
+pub fn tableau_from_index(index: usize) -> Option<Tableau> {
+    match index {
+        0 => Some(Tableau::Tableau1),
+        1 => Some(Tableau::Tableau2),
+        2 => Some(Tableau::Tableau3),
+        3 => Some(Tableau::Tableau4),
+        4 => Some(Tableau::Tableau5),
+        5 => Some(Tableau::Tableau6),
+        6 => Some(Tableau::Tableau7),
+        _ => None,
+    }
+}
+
+/// Convert a zero-based foundation slot (0..=3) into [`Foundation`].
+pub fn foundation_from_slot(slot: u8) -> Option<Foundation> {
+    match slot {
+        0 => Some(Foundation::Foundation1),
+        1 => Some(Foundation::Foundation2),
+        2 => Some(Foundation::Foundation3),
+        3 => Some(Foundation::Foundation4),
+        _ => None,
+    }
+}
+
+/// Convert a tableau skip count (0..=12) into [`SkipCards`].
+pub fn skip_cards_from_count(skip: usize) -> Option<SkipCards> {
+    match skip {
+        0 => Some(SkipCards::Skip0),
+        1 => Some(SkipCards::Skip1),
+        2 => Some(SkipCards::Skip2),
+        3 => Some(SkipCards::Skip3),
+        4 => Some(SkipCards::Skip4),
+        5 => Some(SkipCards::Skip5),
+        6 => Some(SkipCards::Skip6),
+        7 => Some(SkipCards::Skip7),
+        8 => Some(SkipCards::Skip8),
+        9 => Some(SkipCards::Skip9),
+        10 => Some(SkipCards::Skip10),
+        11 => Some(SkipCards::Skip11),
+        12 => Some(SkipCards::Skip12),
+        _ => None,
+    }
+}

solitaire_core/src/lib.rs

@@ -1,9 +1,23 @@
 pub mod achievement;
-pub mod card;
-pub mod deck;
 pub mod error;
 pub mod game_state;
-pub mod pile;
+pub mod klondike_adapter;
-pub mod rules;
 pub mod scoring;
-pub mod solver;
+
+// Re-export the upstream types that cross the solitaire_core API boundary so
+// downstream crates (engine, wasm) can import from one place without a direct
+// `klondike` / `card_game` dep.
+//
+// `KlondikePileStack`, `SkipCards` and `TableauStack` are intentionally NOT
+// re-exported — they are only used internally (in `klondike_adapter.rs` and
+// when decoding instructions to piles in `instruction_to_piles`) and do not
+// appear in any public method signature.
+pub use card_game::{Card, Deck, Rank, Session, SolveError, Suit};
+pub use klondike::{DrawStockConfig, Foundation, Klondike, KlondikeInstruction, KlondikePile, Tableau};
+
+// Solvability check API (delegates to `card_game::Session::solve`); replaces the
+// former `solitaire_data::solver` wrapper module.
+pub use game_state::{DEFAULT_SOLVE_MOVES_BUDGET, DEFAULT_SOLVE_STATES_BUDGET, SolveOutcome};
+
+#[cfg(test)]
+mod proptest_tests;

solitaire_core/src/pile.rs

@@ -1,133 +0,0 @@
-use crate::card::{Card, Suit};
-use serde::{Deserialize, Serialize};
-
-/// Identifies which pile on the board a set of cards belongs to.
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
-pub enum PileType {
-    /// The face-down draw pile.
-    Stock,
-    /// The face-up discard pile drawn to.
-    Waste,
-    /// One of the four foundation slots (0..=3). The claimed suit, if any,
-    /// is derived from the bottom card of the pile (always an Ace by
-    /// construction).
-    Foundation(u8),
-    /// One of the seven tableau columns (0–6).
-    Tableau(usize),
-}
-
-/// A named collection of cards in a specific board position.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct Pile {
-    /// Which pile this is (Stock, Waste, Foundation slot, or Tableau column).
-    pub pile_type: PileType,
-    /// Cards in the pile, bottom-to-top stacking order. Last element is the top card.
-    pub cards: Vec<Card>,
-}
-
-impl Pile {
-    /// Creates a new empty pile of the given type.
-    pub fn new(pile_type: PileType) -> Self {
-        Self {
-            pile_type,
-            cards: Vec::new(),
-        }
-    }
-
-    /// Returns a reference to the top (last) card, or `None` if empty.
-    pub fn top(&self) -> Option<&Card> {
-        self.cards.last()
-    }
-
-    /// For foundation piles: returns `Some(suit)` once at least one card has
-    /// landed (the bottom card is always an Ace of the claimed suit).
-    /// Returns `None` for empty foundations or non-foundation piles.
-    pub fn claimed_suit(&self) -> Option<Suit> {
-        match self.pile_type {
-            PileType::Foundation(_) => self.cards.first().map(|c| c.suit),
-            _ => None,
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::card::{Card, Rank, Suit};
-
-    #[test]
-    fn new_pile_is_empty() {
-        let pile = Pile::new(PileType::Stock);
-        assert!(pile.cards.is_empty());
-    }
-
-    #[test]
-    fn pile_top_returns_last_card() {
-        let mut pile = Pile::new(PileType::Waste);
-        pile.cards.push(Card {
-            id: 0,
-            suit: Suit::Hearts,
-            rank: Rank::Ace,
-            face_up: true,
-        });
-        pile.cards.push(Card {
-            id: 1,
-            suit: Suit::Clubs,
-            rank: Rank::Two,
-            face_up: true,
-        });
-        assert_eq!(pile.top().unwrap().id, 1);
-    }
-
-    #[test]
-    fn pile_top_on_empty_is_none() {
-        let pile = Pile::new(PileType::Waste);
-        assert!(pile.top().is_none());
-    }
-
-    #[test]
-    fn pile_type_foundation_uses_slot_index() {
-        assert_ne!(PileType::Foundation(0), PileType::Foundation(3));
-    }
-
-    #[test]
-    fn pile_type_tableau_uses_index() {
-        assert_ne!(PileType::Tableau(0), PileType::Tableau(6));
-    }
-
-    #[test]
-    fn claimed_suit_is_none_for_empty_foundation() {
-        let pile = Pile::new(PileType::Foundation(0));
-        assert!(pile.claimed_suit().is_none());
-    }
-
-    #[test]
-    fn claimed_suit_is_none_for_non_foundation() {
-        let mut pile = Pile::new(PileType::Tableau(0));
-        pile.cards.push(Card {
-            id: 0,
-            suit: Suit::Hearts,
-            rank: Rank::Ace,
-            face_up: true,
-        });
-        assert!(pile.claimed_suit().is_none());
-    }
-
-    #[test]
-    fn claimed_suit_returns_bottom_card_suit() {
-        let mut pile = Pile::new(PileType::Foundation(2));
-        pile.cards.push(Card {
-            id: 0,
-            suit: Suit::Hearts,
-            rank: Rank::Ace,
-            face_up: true,
-        });
-        pile.cards.push(Card {
-            id: 1,
-            suit: Suit::Hearts,
-            rank: Rank::Two,
-            face_up: true,
-        });
-        assert_eq!(pile.claimed_suit(), Some(Suit::Hearts));
-    }
-}

solitaire_core/src/proptest_tests.rs

@@ -0,0 +1,259 @@
+use card_game::{Card, Game};
+use klondike::{DrawStockConfig, Foundation, KlondikePile, Tableau};
+use proptest::prelude::*;
+
+use crate::game_state::GameState;
+
+// ---------------------------------------------------------------------------
+// Shared helpers
+// ---------------------------------------------------------------------------
+
+/// Collect all cards across every pile in a fixed traversal order:
+/// stock → waste → foundations 1–4 → tableaux 1–7.
+///
+/// The order is deterministic for a given game state, so two calls on
+/// equivalent states produce identical Vec outputs — the right fingerprint
+/// for undo-reversibility checks.
+fn all_cards(game: &GameState) -> Vec<Card> {
+    let foundations = [
+        Foundation::Foundation1,
+        Foundation::Foundation2,
+        Foundation::Foundation3,
+        Foundation::Foundation4,
+    ];
+    let tableaux = [
+        Tableau::Tableau1,
+        Tableau::Tableau2,
+        Tableau::Tableau3,
+        Tableau::Tableau4,
+        Tableau::Tableau5,
+        Tableau::Tableau6,
+        Tableau::Tableau7,
+    ];
+
+    let mut cards: Vec<Card> = game.stock_cards().iter().map(|(c, _)| c.clone()).collect();
+    cards.extend(game.waste_cards().iter().map(|(c, _)| c.clone()));
+    for f in &foundations {
+        cards.extend(
+            game.pile(KlondikePile::Foundation(*f))
+                .iter()
+                .map(|(c, _)| c.clone()),
+        );
+    }
+    for t in &tableaux {
+        cards.extend(game.pile(KlondikePile::Tableau(*t)).iter().map(|(c, _)| c.clone()));
+    }
+    cards
+}
+
+fn draw_mode_strategy() -> impl Strategy<Value = DrawStockConfig> {
+    prop_oneof![Just(DrawStockConfig::DrawOne), Just(DrawStockConfig::DrawThree)]
+}
+
+/// Apply a sequence of random actions to a game, silently ignoring errors.
+///
+/// Each action is `(draw_flag, move_index)`:
+/// - `draw_flag = true`  → call `game.draw()`
+/// - `draw_flag = false` → pick the `move_index % len`th legal instruction
+///   from `possible_instructions()` and apply it via `apply_instruction()`.
+///
+/// `possible_instructions()` may return `RotateStock`, which
+/// `apply_instruction()` dispatches to `game.draw()`; ordinary instructions
+/// are equivalent to `move_cards(from, to, count)`.
+fn apply_random_actions(game: &mut GameState, actions: &[(bool, usize)]) {
+    for &(do_draw, idx) in actions {
+        if do_draw {
+            let _ = game.draw();
+        } else {
+            let moves = game.possible_instructions();
+            if moves.is_empty() {
+                continue;
+            }
+            let instruction = moves[idx % moves.len()];
+            let _ = game.apply_instruction(instruction);
+        }
+    }
+}
+
+/// Apply one move from `possible_instructions()` (or a draw if no move is
+/// available), using `move_idx` to select among the legal options.
+/// Returns `true` when a move was successfully applied.
+fn apply_one_move(game: &mut GameState, move_idx: usize) -> bool {
+    if game.is_won() {
+        return false;
+    }
+    let moves = game.possible_instructions();
+    if moves.is_empty() {
+        return game.draw().is_ok();
+    }
+    let instruction = moves[move_idx % moves.len()];
+    game.apply_instruction(instruction).is_ok()
+}
+
+// ---------------------------------------------------------------------------
+// Properties
+// ---------------------------------------------------------------------------
+
+proptest! {
+    /// `check_auto_complete()` and `is_win_trivial()` must agree on every
+    /// reachable game state.
+    ///
+    /// The upstream `Klondike::is_win_trivial()` checks that the stock pile
+    /// (both face-down and face-up halves) is completely empty AND that all
+    /// tableau columns have no face-down cards.  Ferrous `check_auto_complete()`
+    /// checks the same three conditions individually (stock empty, waste empty,
+    /// all tableau cards face-up).  This property guards against any semantic
+    /// drift between the two implementations so that delegating to upstream is
+    /// safe.
+    ///
+    /// If this property ever fails, `check_auto_complete()` must NOT be fully
+    /// replaced — the Ferrous conditions must be preserved and `is_win_trivial()`
+    /// used only as a supplementary guard.
+    #[test]
+    fn check_auto_complete_agrees_with_is_win_trivial(
+        seed in any::<u64>(),
+        draw_mode in draw_mode_strategy(),
+        actions in prop::collection::vec((any::<bool>(), 0usize..200), 0..30),
+    ) {
+        let mut game = GameState::new(seed, draw_mode);
+        apply_random_actions(&mut game, &actions);
+        prop_assert_eq!(
+            game.check_auto_complete(),
+            game.session().state().state().is_win_trivial(),
+            "check_auto_complete() disagreed with is_win_trivial() after {:?} actions",
+            actions.len(),
+        );
+    }
+
+    /// `check_win()` and `is_win()` must agree on every reachable game state.
+    #[test]
+    fn check_win_agrees_with_is_win(
+        seed in any::<u64>(),
+        draw_mode in draw_mode_strategy(),
+        actions in prop::collection::vec((any::<bool>(), 0usize..200), 0..30),
+    ) {
+        let mut game = GameState::new(seed, draw_mode);
+        apply_random_actions(&mut game, &actions);
+        prop_assert_eq!(
+            game.check_win(),
+            game.session().state().state().is_win(),
+            "check_win() disagreed with is_win()",
+        );
+    }
+
+    /// All 52 card IDs must be present exactly once across every pile after
+    /// any reachable sequence of draw + move_cards actions.
+    ///
+    /// Catches two bug classes at once:
+    /// - Card loss (fewer than 52 unique IDs after the sequence).
+    /// - Card duplication (52 total but deduplication reduces the set).
+    #[test]
+    fn all_52_cards_always_present(
+        seed in any::<u64>(),
+        draw_mode in draw_mode_strategy(),
+        actions in prop::collection::vec((any::<bool>(), 0usize..200), 0..30),
+    ) {
+        let mut game = GameState::new(seed, draw_mode);
+        apply_random_actions(&mut game, &actions);
+
+        let cards = all_cards(&game);
+        prop_assert_eq!(cards.len(), 52, "card count ≠ 52 (got {})", cards.len());
+        let unique: std::collections::HashSet<Card> = cards.iter().cloned().collect();
+        prop_assert_eq!(
+            unique.len(), 52,
+            "duplicate cards found after dedup — a card was cloned"
+        );
+    }
+
+    /// `GameState::new(seed, draw_mode)` must be deterministic: two calls
+    /// with the same arguments must produce identical initial pile layouts.
+    ///
+    /// Pins that the deal is seeded from `seed` alone and not from any
+    /// implicit source like wall-clock time or global state.
+    #[test]
+    fn deal_is_deterministic(
+        seed in any::<u64>(),
+        draw_mode in draw_mode_strategy(),
+    ) {
+        let a = GameState::new(seed, draw_mode);
+        let b = GameState::new(seed, draw_mode);
+        prop_assert_eq!(
+            all_cards(&a),
+            all_cards(&b),
+            "same seed + draw_mode produced different deals",
+        );
+    }
+
+    /// After applying any single legal move and immediately undoing it, the
+    /// pile layout and move_count must be identical to their pre-move values.
+    ///
+    /// `setup_actions` drives the game to an arbitrary mid-game position;
+    /// `move_idx` selects which legal move to apply and then undo.
+    ///
+    /// The score is intentionally excluded: `undo()` applies a −15 penalty
+    /// that is by design, not a regression.
+    #[test]
+    fn undo_restores_pile_layout_and_move_count(
+        seed in any::<u64>(),
+        draw_mode in draw_mode_strategy(),
+        setup_actions in prop::collection::vec((any::<bool>(), 0usize..200), 0..20),
+        move_idx in 0usize..200,
+    ) {
+        let mut game = GameState::new(seed, draw_mode);
+        apply_random_actions(&mut game, &setup_actions);
+
+        // Snapshot the state before the move.
+        let before_ids = all_cards(&game);
+        let before_move_count = game.move_count();
+
+        // Apply one move.
+        if !apply_one_move(&mut game, move_idx) || game.is_won() {
+            return Ok(()); // nothing to undo
+        }
+
+        // Undo and verify.
+        prop_assert!(
+            game.undo().is_ok(),
+            "undo must succeed immediately after a successful move",
+        );
+        prop_assert_eq!(
+            all_cards(&game),
+            before_ids,
+            "pile layout after undo differs from the pre-move snapshot",
+        );
+        prop_assert_eq!(
+            game.move_count(),
+            before_move_count,
+            "move_count after undo must equal the pre-move value",
+        );
+    }
+
+    /// Every move returned by `possible_instructions()` must succeed when
+    /// applied via `move_cards()`.
+    ///
+    /// `possible_instructions()` and `move_cards()` both validate moves
+    /// through the same upstream rule engine. This property ensures no
+    /// drift has opened up between what the engine reports as legal and
+    /// what it actually accepts.
+    #[test]
+    fn legal_moves_always_succeed(
+        seed in any::<u64>(),
+        draw_mode in draw_mode_strategy(),
+        setup_actions in prop::collection::vec((any::<bool>(), 0usize..200), 0..20),
+    ) {
+        let mut game = GameState::new(seed, draw_mode);
+        apply_random_actions(&mut game, &setup_actions);
+
+        for instruction in game.possible_instructions() {
+            // Clone so each move is tried from the same starting state.
+            let mut trial = game.clone();
+            let result = trial.apply_instruction(instruction);
+            prop_assert!(
+                result.is_ok(),
+                "possible_instructions() reported {instruction:?} \
+                 as legal but the call returned Err: {result:?}",
+            );
+        }
+    }
+
+}

solitaire_core/src/rules.rs

@@ -1,228 +0,0 @@
-use crate::card::{Card, Rank};
-use crate::pile::Pile;
-
-/// Returns `true` if `card` can be placed on the foundation `pile`.
-///
-/// Foundation rules:
-/// - When the pile is empty, any Ace is accepted; the placed Ace's suit
-///   becomes the pile's claimed suit (derived from the bottom card via
-///   [`Pile::claimed_suit`](crate::pile::Pile::claimed_suit)).
-/// - When the pile is non-empty, the next card must match the top card's
-///   suit and be exactly one rank higher.
-#[must_use]
-pub fn can_place_on_foundation(card: &Card, pile: &Pile) -> bool {
-    match pile.cards.last() {
-        None => card.rank == Rank::Ace,
-        Some(top) => card.suit == top.suit && card.rank.checked_sub(1) == Some(top.rank),
-    }
-}
-
-/// Returns `true` if `card` (or the bottom card of a sequence) can be placed on `pile` in the tableau.
-///
-/// Tableau rules: Kings go on empty piles; otherwise alternating colour, one rank lower.
-#[must_use]
-pub fn can_place_on_tableau(card: &Card, pile: &Pile) -> bool {
-    match pile.cards.last() {
-        None => card.rank == Rank::King,
-        Some(top) => {
-            top.face_up
-                && card.rank.checked_add(1) == Some(top.rank)
-                && card.suit.is_red() != top.suit.is_red()
-        }
-    }
-}
-
-/// Returns `true` if `cards` is a legal tableau run on its own — every
-/// adjacent pair descends by one rank and alternates colour. A single
-/// card is trivially valid. The destination check is separate; this
-/// only validates the sequence's *internal* structure, which the tableau
-/// move path must enforce so a player can't smuggle an arbitrary stack
-/// onto another column when the bottom card happens to land legally.
-#[must_use]
-pub fn is_valid_tableau_sequence(cards: &[Card]) -> bool {
-    cards.windows(2).all(|w| {
-        w[0].rank.checked_sub(1) == Some(w[1].rank) && w[0].suit.is_red() != w[1].suit.is_red()
-    })
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::card::{Card, Rank, Suit};
-    use crate::pile::{Pile, PileType};
-
-    fn card(suit: Suit, rank: Rank) -> Card {
-        Card {
-            id: 0,
-            suit,
-            rank,
-            face_up: true,
-        }
-    }
-
-    fn pile_with(pile_type: PileType, cards: Vec<Card>) -> Pile {
-        Pile { pile_type, cards }
-    }
-
-    // Foundation tests
-    #[test]
-    fn foundation_ace_on_empty_is_valid() {
-        // Every suit's Ace must land on an empty foundation slot regardless of
-        // its slot index; the slot claims the suit only after the Ace lands.
-        for suit in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades] {
-            let c = card(suit, Rank::Ace);
-            let p = Pile::new(PileType::Foundation(0));
-            assert!(
-                can_place_on_foundation(&c, &p),
-                "Ace of {suit:?} must land on empty slot 0",
-            );
-        }
-    }
-
-    #[test]
-    fn foundation_non_ace_on_empty_is_invalid() {
-        let c = card(Suit::Hearts, Rank::Two);
-        let p = Pile::new(PileType::Foundation(0));
-        assert!(!can_place_on_foundation(&c, &p));
-    }
-
-    #[test]
-    fn foundation_two_on_ace_same_suit_is_valid() {
-        let c = card(Suit::Clubs, Rank::Two);
-        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Clubs, Rank::Ace)]);
-        assert!(can_place_on_foundation(&c, &p));
-    }
-
-    #[test]
-    fn foundation_second_card_must_match_claimed_suit() {
-        // Place Ace of Hearts on slot 0, then attempt 2 of Spades — rejected
-        // because the slot's claimed suit is Hearts after the Ace lands.
-        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Hearts, Rank::Ace)]);
-        let c = card(Suit::Spades, Rank::Two);
-        assert!(!can_place_on_foundation(&c, &p));
-    }
-
-    #[test]
-    fn foundation_skipping_rank_is_invalid() {
-        let c = card(Suit::Diamonds, Rank::Three);
-        let p = pile_with(
-            PileType::Foundation(0),
-            vec![card(Suit::Diamonds, Rank::Ace)],
-        );
-        assert!(!can_place_on_foundation(&c, &p));
-    }
-
-    // Tableau tests
-    #[test]
-    fn tableau_king_on_empty_is_valid() {
-        let c = card(Suit::Hearts, Rank::King);
-        let p = Pile::new(PileType::Tableau(0));
-        assert!(can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_non_king_on_empty_is_invalid() {
-        let c = card(Suit::Hearts, Rank::Queen);
-        let p = Pile::new(PileType::Tableau(0));
-        assert!(!can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_red_on_black_one_lower_is_valid() {
-        let c = card(Suit::Hearts, Rank::Nine);
-        let p = pile_with(PileType::Tableau(0), vec![card(Suit::Spades, Rank::Ten)]);
-        assert!(can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_same_color_is_invalid() {
-        let c = card(Suit::Clubs, Rank::Nine);
-        let p = pile_with(PileType::Tableau(0), vec![card(Suit::Spades, Rank::Ten)]);
-        assert!(!can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_wrong_rank_difference_is_invalid() {
-        let c = card(Suit::Hearts, Rank::Eight);
-        let p = pile_with(PileType::Tableau(0), vec![card(Suit::Spades, Rank::Ten)]);
-        assert!(!can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_black_on_red_one_lower_is_valid() {
-        let c = card(Suit::Clubs, Rank::Six);
-        let p = pile_with(PileType::Tableau(0), vec![card(Suit::Hearts, Rank::Seven)]);
-        assert!(can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn foundation_king_on_queen_completes_suit() {
-        // The last card placed to complete a foundation is always King on Queen.
-        let c = card(Suit::Spades, Rank::King);
-        let p = pile_with(
-            PileType::Foundation(0),
-            vec![card(Suit::Spades, Rank::Queen)],
-        );
-        assert!(can_place_on_foundation(&c, &p));
-    }
-
-    #[test]
-    fn foundation_king_wrong_suit_is_invalid() {
-        // King of Hearts cannot go on a Spades-claimed foundation even if rank matches.
-        let c = card(Suit::Hearts, Rank::King);
-        let p = pile_with(
-            PileType::Foundation(0),
-            vec![card(Suit::Spades, Rank::Queen)],
-        );
-        assert!(!can_place_on_foundation(&c, &p));
-    }
-
-    #[test]
-    fn tableau_ace_on_two_different_color_is_valid() {
-        // Ace (rank 1) can be placed on a Two of the opposite colour in the tableau.
-        // rank check: Ace.value() + 1 = 2 == Two.value() — passes.
-        let c = card(Suit::Hearts, Rank::Ace);
-        let p = pile_with(PileType::Tableau(0), vec![card(Suit::Spades, Rank::Two)]);
-        assert!(can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_same_rank_different_color_is_invalid() {
-        // Two cards of the same rank cannot be stacked regardless of colour.
-        let c = card(Suit::Hearts, Rank::Nine);
-        let p = pile_with(PileType::Tableau(0), vec![card(Suit::Spades, Rank::Nine)]);
-        assert!(!can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_face_down_destination_top_is_invalid() {
-        // A face-down top card must never be a valid placement target.
-        let c = card(Suit::Hearts, Rank::Nine);
-        let mut top = card(Suit::Spades, Rank::Ten);
-        top.face_up = false;
-        let p = pile_with(PileType::Tableau(0), vec![top]);
-        assert!(!can_place_on_tableau(&c, &p));
-    }
-
-    #[test]
-    fn tableau_sequence_validation() {
-        // Single card is trivially a valid sequence.
-        assert!(is_valid_tableau_sequence(&[card(Suit::Hearts, Rank::Five)]));
-        // Valid descending alternating-colour run K♠ Q♥ J♣.
-        assert!(is_valid_tableau_sequence(&[
-            card(Suit::Spades, Rank::King),
-            card(Suit::Hearts, Rank::Queen),
-            card(Suit::Clubs, Rank::Jack),
-        ]));
-        // Same colour twice (Q♠ on K♠) — invalid.
-        assert!(!is_valid_tableau_sequence(&[
-            card(Suit::Spades, Rank::King),
-            card(Suit::Spades, Rank::Queen),
-        ]));
-        // Rank gap (K♠ → J♥) — invalid.
-        assert!(!is_valid_tableau_sequence(&[
-            card(Suit::Spades, Rank::King),
-            card(Suit::Hearts, Rank::Jack),
-        ]));
-    }
-}

solitaire_core/src/scoring.rs

@@ -1,50 +1,9 @@
-use crate::pile::PileType;
+//! Ferrous-specific scoring policy layered on top of upstream `klondike`.
-
+//!
-/// Score delta for moving cards from `from` to `to`.
+//! Upstream [`klondike::KlondikeStats::score`] owns the per-move point values
-///
+//! (move-to-foundation, flip-up bonus, recycle penalty, etc.). The functions
-/// Windows XP Standard scoring:
+//! here are the Ferrous Solitaire house rules that upstream has no opinion on —
-/// - +10 for any card reaching a foundation pile
+//! currently just the win-time bonus shown in the win modal.
-/// - +5 for a waste → tableau move
-/// - -15 for a foundation → tableau (take-from-foundation) move
-/// - 0 for all other moves
-///
-/// Note: the +5 flip bonus for exposing a face-down tableau card is applied
-/// separately in `game_state::move_cards` because it depends on post-move state.
-pub fn score_move(from: &PileType, to: &PileType) -> i32 {
-    match to {
-        PileType::Foundation(_) => 10,
-        PileType::Tableau(_) => match from {
-            PileType::Waste => 5,
-            PileType::Foundation(_) => -15,
-            _ => 0,
-        },
-        _ => 0,
-    }
-}
-
-/// Score penalty applied when the player uses undo: -15.
-pub fn score_undo() -> i32 {
-    -15
-}
-
-/// Score bonus awarded when a face-down tableau card is flipped face-up: +5.
-pub fn score_flip() -> i32 {
-    5
-}
-
-/// Score penalty for recycling the waste pile back to stock.
-///
-/// Windows standard: the first N recycles are free (N=1 for Draw-1, N=3 for Draw-3).
-/// Subsequent recycles cost -100 (Draw-1) or -20 (Draw-3).
-/// `recycle_count` is the new total count **after** this recycle.
-pub fn score_recycle(recycle_count: u32, is_draw_three: bool) -> i32 {
-    let (free, penalty) = if is_draw_three {
-        (3_u32, -20_i32)
-    } else {
-        (1_u32, -100_i32)
-    };
-    if recycle_count > free { penalty } else { 0 }
-}
 
 /// Time bonus added to the score on a win: `700_000 / elapsed_seconds`.
 /// Returns 0 when `elapsed_seconds` is 0 to avoid division by zero.
@@ -54,99 +13,3 @@ pub fn compute_time_bonus(elapsed_seconds: u64) -> i32 {
     }
     (700_000u64 / elapsed_seconds).min(i32::MAX as u64) as i32
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn move_to_foundation_scores_ten() {
-        assert_eq!(score_move(&PileType::Waste, &PileType::Foundation(2)), 10);
-        assert_eq!(
-            score_move(&PileType::Tableau(0), &PileType::Foundation(0)),
-            10
-        );
-    }
-
-    #[test]
-    fn waste_to_tableau_scores_five() {
-        assert_eq!(score_move(&PileType::Waste, &PileType::Tableau(3)), 5);
-    }
-
-    #[test]
-    fn tableau_to_tableau_scores_zero() {
-        assert_eq!(score_move(&PileType::Tableau(0), &PileType::Tableau(1)), 0);
-    }
-
-    #[test]
-    fn undo_penalty_is_negative_fifteen() {
-        assert_eq!(score_undo(), -15);
-    }
-
-    #[test]
-    fn time_bonus_at_100_seconds() {
-        assert_eq!(compute_time_bonus(100), 7000);
-    }
-
-    #[test]
-    fn time_bonus_at_zero_is_zero() {
-        assert_eq!(compute_time_bonus(0), 0);
-    }
-
-    #[test]
-    fn time_bonus_at_one_second() {
-        assert_eq!(compute_time_bonus(1), 700_000);
-    }
-
-    #[test]
-    fn foundation_to_tableau_penalises_fifteen() {
-        // Moving a card back off a foundation (take_from_foundation rule) costs -15.
-        assert_eq!(
-            score_move(&PileType::Foundation(0), &PileType::Tableau(0)),
-            -15
-        );
-    }
-
-    #[test]
-    fn move_to_stock_or_waste_scores_zero() {
-        // These destinations are illegal moves in practice, but the function
-        // must not panic and should return 0.
-        assert_eq!(score_move(&PileType::Waste, &PileType::Stock), 0);
-        assert_eq!(score_move(&PileType::Waste, &PileType::Waste), 0);
-    }
-
-    #[test]
-    fn time_bonus_is_capped_at_i32_max_for_huge_values() {
-        // Very short elapsed time would overflow without the .min() guard.
-        let bonus = compute_time_bonus(1);
-        assert!(
-            bonus >= 0,
-            "time bonus must be non-negative after u64→i32 cast"
-        );
-    }
-
-    #[test]
-    fn flip_bonus_is_five() {
-        assert_eq!(score_flip(), 5);
-    }
-
-    #[test]
-    fn recycle_draw1_first_pass_free() {
-        assert_eq!(score_recycle(1, false), 0);
-    }
-
-    #[test]
-    fn recycle_draw1_second_pass_penalised() {
-        assert_eq!(score_recycle(2, false), -100);
-    }
-
-    #[test]
-    fn recycle_draw3_third_pass_free() {
-        assert_eq!(score_recycle(3, true), 0);
-    }
-
-    #[test]
-    fn recycle_draw3_fourth_pass_penalised() {
-        assert_eq!(score_recycle(4, true), -20);
-    }
-}

solitaire_data/Cargo.toml

@@ -7,15 +7,23 @@ edition.workspace = true
 [dependencies]
 solitaire_core = { workspace = true }
 solitaire_sync = { workspace = true }
+klondike  = { workspace = true }
+card_game = { workspace = true }
 serde          = { workspace = true }
 serde_json     = { workspace = true }
 chrono         = { workspace = true }
 thiserror      = { workspace = true }
 async-trait    = { workspace = true }
+uuid           = { workspace = true }
+
+# These deps are not available / not needed on wasm32:
+#   dirs     — platform data directories (no filesystem on browser)
+#   reqwest  — native HTTP client (sync/analytics gated out on wasm32)
+#   tokio    — OS-threaded async runtime (mio doesn't compile on wasm32)
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 dirs           = { workspace = true }
 reqwest        = { workspace = true }
 tokio          = { workspace = true }
-uuid           = { workspace = true }
 
 # `keyring-core` is the typed Entry/Error API used by
 # `auth_tokens`. The crate's own dependency tree pulls in
@@ -24,17 +32,14 @@ uuid           = { workspace = true }
 # on bionic). On Android `auth_tokens` falls back to a stub
 # implementation that always returns `KeychainUnavailable`; the
 # real backend lands when we wire Android Keystore via JNI.
-[target.'cfg(not(target_os = "android"))'.dependencies]
+[target.'cfg(all(not(target_os = "android"), not(target_arch = "wasm32")))'.dependencies]
 keyring-core   = { workspace = true }
 
 [target.'cfg(target_os = "android")'.dependencies]
 jni            = { workspace = true }
-# android_keystore.rs uses bevy::android::ANDROID_APP to obtain the
-# process-wide JavaVM handle for JNI. Must be listed here so the
-# symbol resolves when cross-compiling for Android targets.
-bevy           = { workspace = true }
 
 [dev-dependencies]
+solitaire_core   = { workspace = true, features = ["test-support"] }
 solitaire_server = { path = "../solitaire_server" }
 solitaire_sync   = { workspace = true }
 axum             = { workspace = true }
@@ -42,3 +47,6 @@ sqlx             = { workspace = true }
 jsonwebtoken     = { workspace = true }
 uuid             = { workspace = true }
 chrono           = { workspace = true }
+
+[lints]
+workspace = true

solitaire_data/src/android_jni.rs

@@ -0,0 +1,65 @@
+//! Safe JNI bridge for Android platform integration.
+//!
+//! Reconstructing the raw `JavaVM` / `NativeActivity` handles handed over by
+//! the Android runtime requires `unsafe` FFI. That single reconstruction lives
+//! in `solitaire_app`'s entry point ([`solitaire_app::android_main`]); this
+//! module only ever stores the resulting *safe* [`JavaVM`] and activity
+//! [`GlobalRef`] and hands callers an attached [`JNIEnv`].
+//!
+//! As a result every consumer of Android JNI — the keystore, clipboard, and
+//! safe-area subsystems — goes through the safe functions here and stays
+//! `forbid(unsafe_code)`. The only crate carrying `unsafe` is `solitaire_app`.
+//!
+//! Only compiled and linked on `target_os = "android"`.
+
+use jni::objects::{GlobalRef, JObject};
+use jni::{JNIEnv, JavaVM};
+use std::sync::OnceLock;
+
+static ANDROID_JVM: OnceLock<JavaVM> = OnceLock::new();
+static ANDROID_ACTIVITY: OnceLock<GlobalRef> = OnceLock::new();
+
+/// Store the process-wide [`JavaVM`]. Called once from Android startup
+/// (`solitaire_app::android_main`); subsequent calls are ignored.
+pub fn set_jvm(vm: JavaVM) {
+    let _ = ANDROID_JVM.set(vm);
+}
+
+/// Store a global reference to the `NativeActivity`. Called once from Android
+/// startup; subsequent calls are ignored.
+pub fn set_activity(activity: GlobalRef) {
+    let _ = ANDROID_ACTIVITY.set(activity);
+}
+
+/// Run `f` with a [`JNIEnv`] attached to the current thread.
+///
+/// Returns an error string if the bridge has not been initialised yet or the
+/// thread cannot be attached. The closure's JNI errors are surfaced through the
+/// same `String` channel so callers have a single error type to map.
+pub fn with_env<F, R>(f: F) -> Result<R, String>
+where
+    F: for<'local> FnOnce(&mut JNIEnv<'local>) -> jni::errors::Result<R>,
+{
+    let vm = ANDROID_JVM
+        .get()
+        .ok_or_else(|| "Android JavaVM not initialised".to_string())?;
+    let mut env = vm
+        .attach_current_thread_permanently()
+        .map_err(|e| format!("attach_current_thread: {e}"))?;
+    f(&mut env).map_err(|e| format!("JNI: {e}"))
+}
+
+/// Run `f` with an attached [`JNIEnv`] and the `NativeActivity` object.
+///
+/// Like [`with_env`] but also resolves the cached activity global reference, so
+/// callers that need to invoke instance methods on the activity (clipboard,
+/// window insets) never touch a raw handle.
+pub fn with_activity_env<F, R>(f: F) -> Result<R, String>
+where
+    F: for<'local> FnOnce(&mut JNIEnv<'local>, &JObject<'local>) -> jni::errors::Result<R>,
+{
+    let activity = ANDROID_ACTIVITY
+        .get()
+        .ok_or_else(|| "Android activity not initialised".to_string())?;
+    with_env(|env| f(env, activity.as_obj()))
+}

solitaire_data/src/android_keystore.rs

@@ -14,7 +14,7 @@
 ///
 /// Only compiled and linked on `target_os = "android"`.
 use jni::{
-    JNIEnv, JavaVM,
+    JNIEnv,
     objects::{JByteArray, JObject, JObjectArray, JValue, JValueOwned},
 };
 use serde::{Deserialize, Serialize};
@@ -36,23 +36,15 @@ struct TokenBlob {
 // JVM helper
 // ---------------------------------------------------------------------------
 
+/// Run `f` with an attached `JNIEnv`, delegating thread attach and the
+/// `JavaVM` handle to the safe [`crate::android_jni`] bridge. The bridge is
+/// initialised once from Android startup, so the keystore never touches a raw
+/// pointer and this module stays `forbid(unsafe_code)`.
 fn with_jvm<F, R>(f: F) -> Result<R, TokenError>
 where
     F: for<'env> FnOnce(&mut JNIEnv<'env>) -> Result<R, jni::errors::Error>,
 {
-    let app = bevy::android::ANDROID_APP
+    crate::android_jni::with_env(f).map_err(TokenError::Keyring)
-        .get()
-        .ok_or_else(|| TokenError::KeychainUnavailable("ANDROID_APP not initialised".into()))?;
-
-    // SAFETY: vm_as_ptr() is the process-wide JavaVM* set by the Android runtime.
-    let vm = unsafe { JavaVM::from_raw(app.vm_as_ptr().cast()) }
-        .map_err(|e| TokenError::Keyring(format!("JavaVM: {e}")))?;
-
-    let mut env = vm
-        .attach_current_thread_permanently()
-        .map_err(|e| TokenError::Keyring(format!("attach: {e}")))?;
-
-    f(&mut env).map_err(|e| TokenError::Keyring(format!("JNI: {e}")))
 }
 
 // ---------------------------------------------------------------------------
@@ -207,9 +199,10 @@ fn encrypt_gcm(
     .v()?;
 
     // IV is generated by Android's provider; read it back after init.
+    // `getIV()` returns `[B`; the safe `From<JObject>` reinterprets the
+    // returned object reference as a typed byte array.
     let iv_jobj = env.call_method(&cipher, "getIV", "()[B", &[])?.l()?;
-    // SAFETY: the method signature guarantees a byte array return.
+    let iv_arr = JByteArray::from(iv_jobj);
-    let iv_arr = unsafe { JByteArray::from_raw(iv_jobj.into_raw()) };
     let iv = env.convert_byte_array(&iv_arr)?;
 
     let pt_arr = env.byte_array_from_slice(plaintext)?;
@@ -217,8 +210,7 @@ fn encrypt_gcm(
     let ct_jobj = env
         .call_method(&cipher, "doFinal", "([B)[B", &[pt_val.borrow()])?
         .l()?;
-    // SAFETY: doFinal([B) returns [B.
+    let ct_arr = JByteArray::from(ct_jobj);
-    let ct_arr = unsafe { JByteArray::from_raw(ct_jobj.into_raw()) };
     let ciphertext = env.convert_byte_array(&ct_arr)?;
 
     let mut out = Vec::with_capacity(iv.len() + ciphertext.len());
@@ -269,8 +261,7 @@ fn decrypt_gcm(
     let pt_jobj = env
         .call_method(&cipher, "doFinal", "([B)[B", &[ct_val.borrow()])?
         .l()?;
-    // SAFETY: doFinal([B) returns [B.
+    let pt_arr = JByteArray::from(pt_jobj);
-    let pt_arr = unsafe { JByteArray::from_raw(pt_jobj.into_raw()) };
     env.convert_byte_array(&pt_arr)
 }
 
@@ -357,8 +348,9 @@ fn read_map() -> Result<HashMap<String, TokenBlob>, TokenError> {
     }
 
     // --- 2. Legacy path migration ---
-    if let Some(ref lpath) = legacy_path {
+    if let Some(ref lpath) = legacy_path
-        if lpath.exists() {
+        && lpath.exists()
+    {
         let data = read_file_bytes_from(lpath).map_err(|e| match e {
             TokenError::NotFound(_) => TokenError::NotFound(String::new()),
             other => other,
@@ -380,7 +372,6 @@ fn read_map() -> Result<HashMap<String, TokenBlob>, TokenError> {
         }
         // Legacy file corrupt or unrecognised — treat as empty.
     }
-    }
 
     // --- 3. No file found ---
     Ok(HashMap::new())
@@ -468,12 +459,12 @@ pub fn delete_tokens(username: &str) -> Result<(), TokenError> {
 
     if map.is_empty() {
         // No more users — remove the file and the Keystore key.
-        if let Some(path) = token_file_path() {
+        if let Some(path) = token_file_path()
-            if path.exists() {
+            && path.exists()
+        {
             std::fs::remove_file(&path)
                 .map_err(|e| TokenError::Keyring(format!("delete auth_tokens.bin: {e}")))?;
         }
-        }
 
         // Remove the Keystore key so a future re-login generates a fresh key.
         with_jvm(|env| {

solitaire_data/src/auth_tokens.rs

@@ -14,15 +14,14 @@
 //! the Bevy `App`). If no default store is set, all operations in this module
 //! will return [`TokenError::KeychainUnavailable`].
 //!
-//! # Android stub
+//! # Android
 //!
 //! `keyring-core` cannot compile for the android target (its `rpassword`
 //! transitive dep uses `libc::__errno_location`, which Android's bionic
-//! doesn't expose). On Android every function in this module returns
+//! doesn't expose). On Android this module delegates to an Android Keystore
-//! [`TokenError::KeychainUnavailable`] so callers can detect the fallback
+//! JNI backend. `solitaire_app` must initialise the safe
-//! the same way they handle a Linux box without Secret Service. The
+//! [`crate::android_jni`] bridge (via `set_jvm` / `set_activity`) from Android
-//! real Android backend will arrive in the Phase-Android round when we
+//! startup before token operations can succeed.
-//! wire Android Keystore via JNI.
 //!
 //! # Note: no unit tests — requires live OS keychain.
 

solitaire_data/src/difficulty_seeds.rs

@@ -26,227 +26,227 @@ use solitaire_core::game_state::DifficultyLevel;
 
 /// 40 seeds proven winnable within the Easy budget (≤ 1 000 states).
 pub const EASY_SEEDS: &[u64] = &[
-    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Easy, date=2026-05-09)
+    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Easy, date=2026-06-04)
-    0xD1FF_0000_0000_0001,
-    0xD1FF_0000_0000_0002,
-    0xD1FF_0000_0000_0007,
-    0xD1FF_0000_0000_0008,
     0xD1FF_0000_0000_0009,
-    0xD1FF_0000_0000_000E,
+    0xD1FF_0000_0000_0087,
-    0xD1FF_0000_0000_0013,
+    0xD1FF_0000_0000_00EB,
-    0xD1FF_0000_0000_0015,
+    0xD1FF_0000_0000_017F,
-    0xD1FF_0000_0000_0018,
+    0xD1FF_0000_0000_01CE,
-    0xD1FF_0000_0000_001D,
+    0xD1FF_0000_0000_020F,
-    0xD1FF_0000_0000_0021,
+    0xD1FF_0000_0000_0251,
-    0xD1FF_0000_0000_0022,
+    0xD1FF_0000_0000_0275,
-    0xD1FF_0000_0000_0026,
+    0xD1FF_0000_0000_029C,
-    0xD1FF_0000_0000_002C,
+    0xD1FF_0000_0000_02BD,
-    0xD1FF_0000_0000_002E,
+    0xD1FF_0000_0000_02ED,
-    0xD1FF_0000_0000_002F,
+    0xD1FF_0000_0000_038F,
-    0xD1FF_0000_0000_0035,
+    0xD1FF_0000_0000_03C9,
-    0xD1FF_0000_0000_0036,
+    0xD1FF_0000_0000_0415,
-    0xD1FF_0000_0000_003C,
+    0xD1FF_0000_0000_045F,
-    0xD1FF_0000_0000_0045,
+    0xD1FF_0000_0000_04C4,
-    0xD1FF_0000_0000_0046,
+    0xD1FF_0000_0000_04CC,
-    0xD1FF_0000_0000_0048,
+    0xD1FF_0000_0000_04EE,
-    0xD1FF_0000_0000_0049,
+    0xD1FF_0000_0000_0631,
-    0xD1FF_0000_0000_004D,
+    0xD1FF_0000_0000_0651,
-    0xD1FF_0000_0000_004F,
+    0xD1FF_0000_0000_0689,
-    0xD1FF_0000_0000_0050,
+    0xD1FF_0000_0000_0735,
-    0xD1FF_0000_0000_0051,
+    0xD1FF_0000_0000_0748,
-    0xD1FF_0000_0000_0053,
+    0xD1FF_0000_0000_0801,
-    0xD1FF_0000_0000_0054,
+    0xD1FF_0000_0000_0820,
-    0xD1FF_0000_0000_0057,
+    0xD1FF_0000_0000_08F9,
-    0xD1FF_0000_0000_0058,
+    0xD1FF_0000_0000_091C,
-    0xD1FF_0000_0000_005A,
+    0xD1FF_0000_0000_0937,
-    0xD1FF_0000_0000_005B,
+    0xD1FF_0000_0000_09A6,
-    0xD1FF_0000_0000_005C,
+    0xD1FF_0000_0000_09C3,
-    0xD1FF_0000_0000_005D,
+    0xD1FF_0000_0000_09DD,
-    0xD1FF_0000_0000_005F,
+    0xD1FF_0000_0000_0BD9,
-    0xD1FF_0000_0000_0061,
+    0xD1FF_0000_0000_0BEC,
-    0xD1FF_0000_0000_0062,
+    0xD1FF_0000_0000_0BF2,
-    0xD1FF_0000_0000_0063,
+    0xD1FF_0000_0000_0C1B,
-    0xD1FF_0000_0000_0069,
+    0xD1FF_0000_0000_0C26,
+    0xD1FF_0000_0000_0C36,
+    0xD1FF_0000_0000_0C4B,
+    0xD1FF_0000_0000_0C78,
+    0xD1FF_0000_0000_0CBC,
 ];
 
 /// 40 seeds proven winnable within the Medium budget (≤ 5 000 states).
 pub const MEDIUM_SEEDS: &[u64] = &[
-    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Medium, date=2026-05-09)
+    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Medium, date=2026-06-04)
-    0xD1FF_0000_0000_0000,
     0xD1FF_0000_0000_0012,
-    0xD1FF_0000_0000_0016,
+    0xD1FF_0000_0000_002C,
-    0xD1FF_0000_0000_001B,
+    0xD1FF_0000_0000_004B,
-    0xD1FF_0000_0000_001C,
+    0xD1FF_0000_0000_0052,
-    0xD1FF_0000_0000_0020,
+    0xD1FF_0000_0000_0058,
-    0xD1FF_0000_0000_002A,
+    0xD1FF_0000_0000_005E,
-    0xD1FF_0000_0000_0034,
+    0xD1FF_0000_0000_0063,
-    0xD1FF_0000_0000_003A,
-    0xD1FF_0000_0000_0041,
-    0xD1FF_0000_0000_0043,
-    0xD1FF_0000_0000_0060,
-    0xD1FF_0000_0000_006A,
-    0xD1FF_0000_0000_006C,
-    0xD1FF_0000_0000_006E,
-    0xD1FF_0000_0000_006F,
-    0xD1FF_0000_0000_0071,
-    0xD1FF_0000_0000_0072,
-    0xD1FF_0000_0000_0075,
-    0xD1FF_0000_0000_0076,
-    0xD1FF_0000_0000_007B,
-    0xD1FF_0000_0000_007E,
-    0xD1FF_0000_0000_0081,
-    0xD1FF_0000_0000_0083,
-    0xD1FF_0000_0000_0084,
-    0xD1FF_0000_0000_0087,
-    0xD1FF_0000_0000_0090,
-    0xD1FF_0000_0000_0092,
-    0xD1FF_0000_0000_0093,
-    0xD1FF_0000_0000_0098,
     0xD1FF_0000_0000_0099,
-    0xD1FF_0000_0000_009A,
+    0xD1FF_0000_0000_00A9,
-    0xD1FF_0000_0000_009E,
-    0xD1FF_0000_0000_00A5,
-    0xD1FF_0000_0000_00A8,
-    0xD1FF_0000_0000_00AA,
-    0xD1FF_0000_0000_00AB,
-    0xD1FF_0000_0000_00AE,
     0xD1FF_0000_0000_00AF,
-    0xD1FF_0000_0000_00B0,
+    0xD1FF_0000_0000_00BB,
+    0xD1FF_0000_0000_00D1,
+    0xD1FF_0000_0000_00E3,
+    0xD1FF_0000_0000_0108,
+    0xD1FF_0000_0000_010D,
+    0xD1FF_0000_0000_0110,
+    0xD1FF_0000_0000_012F,
+    0xD1FF_0000_0000_0139,
+    0xD1FF_0000_0000_013C,
+    0xD1FF_0000_0000_0148,
+    0xD1FF_0000_0000_015E,
+    0xD1FF_0000_0000_016A,
+    0xD1FF_0000_0000_016F,
+    0xD1FF_0000_0000_0179,
+    0xD1FF_0000_0000_019E,
+    0xD1FF_0000_0000_01A8,
+    0xD1FF_0000_0000_01AB,
+    0xD1FF_0000_0000_01B5,
+    0xD1FF_0000_0000_01B8,
+    0xD1FF_0000_0000_01D3,
+    0xD1FF_0000_0000_01EE,
+    0xD1FF_0000_0000_01F3,
+    0xD1FF_0000_0000_0202,
+    0xD1FF_0000_0000_0203,
+    0xD1FF_0000_0000_021E,
+    0xD1FF_0000_0000_022C,
+    0xD1FF_0000_0000_022D,
+    0xD1FF_0000_0000_0233,
+    0xD1FF_0000_0000_0245,
+    0xD1FF_0000_0000_024E,
 ];
 
 /// 40 seeds proven winnable within the Hard budget (≤ 25 000 states).
 pub const HARD_SEEDS: &[u64] = &[
-    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Hard, date=2026-05-09)
+    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Hard, date=2026-06-04)
-    0xD1FF_0000_0000_001F,
+    0xD1FF_0000_0000_0006,
-    0xD1FF_0000_0000_0024,
+    0xD1FF_0000_0000_0008,
-    0xD1FF_0000_0000_0025,
+    0xD1FF_0000_0000_000F,
-    0xD1FF_0000_0000_0031,
+    0xD1FF_0000_0000_0011,
-    0xD1FF_0000_0000_0032,
+    0xD1FF_0000_0000_0022,
-    0xD1FF_0000_0000_003E,
+    0xD1FF_0000_0000_0023,
-    0xD1FF_0000_0000_004A,
+    0xD1FF_0000_0000_002A,
-    0xD1FF_0000_0000_006D,
+    0xD1FF_0000_0000_002D,
+    0xD1FF_0000_0000_0040,
+    0xD1FF_0000_0000_0042,
+    0xD1FF_0000_0000_0050,
+    0xD1FF_0000_0000_005B,
+    0xD1FF_0000_0000_005D,
+    0xD1FF_0000_0000_0067,
+    0xD1FF_0000_0000_0069,
+    0xD1FF_0000_0000_006E,
+    0xD1FF_0000_0000_0072,
     0xD1FF_0000_0000_0079,
     0xD1FF_0000_0000_007C,
     0xD1FF_0000_0000_0080,
-    0xD1FF_0000_0000_008A,
+    0xD1FF_0000_0000_0081,
-    0xD1FF_0000_0000_0097,
+    0xD1FF_0000_0000_0083,
+    0xD1FF_0000_0000_0091,
+    0xD1FF_0000_0000_009B,
+    0xD1FF_0000_0000_00A1,
     0xD1FF_0000_0000_00B1,
-    0xD1FF_0000_0000_00B2,
-    0xD1FF_0000_0000_00B3,
-    0xD1FF_0000_0000_00B5,
-    0xD1FF_0000_0000_00B7,
-    0xD1FF_0000_0000_00B8,
-    0xD1FF_0000_0000_00B9,
-    0xD1FF_0000_0000_00BA,
-    0xD1FF_0000_0000_00BB,
-    0xD1FF_0000_0000_00BC,
-    0xD1FF_0000_0000_00BD,
-    0xD1FF_0000_0000_00C2,
     0xD1FF_0000_0000_00C3,
-    0xD1FF_0000_0000_00C5,
-    0xD1FF_0000_0000_00CC,
-    0xD1FF_0000_0000_00CE,
-    0xD1FF_0000_0000_00D1,
-    0xD1FF_0000_0000_00D2,
     0xD1FF_0000_0000_00D6,
-    0xD1FF_0000_0000_00D7,
+    0xD1FF_0000_0000_00DD,
-    0xD1FF_0000_0000_00DC,
+    0xD1FF_0000_0000_00E8,
-    0xD1FF_0000_0000_00DF,
+    0xD1FF_0000_0000_00F2,
-    0xD1FF_0000_0000_00E0,
+    0xD1FF_0000_0000_0101,
-    0xD1FF_0000_0000_00E1,
+    0xD1FF_0000_0000_010F,
-    0xD1FF_0000_0000_00E4,
+    0xD1FF_0000_0000_0113,
-    0xD1FF_0000_0000_00E6,
+    0xD1FF_0000_0000_0118,
-    0xD1FF_0000_0000_00E7,
+    0xD1FF_0000_0000_0119,
+    0xD1FF_0000_0000_012D,
+    0xD1FF_0000_0000_0133,
+    0xD1FF_0000_0000_0144,
+    0xD1FF_0000_0000_0147,
 ];
 
 /// 40 seeds proven winnable within the Expert budget (≤ 100 000 states).
 pub const EXPERT_SEEDS: &[u64] = &[
-    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Expert, date=2026-05-09)
+    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Expert, date=2026-06-04)
-    0xD1FF_0000_0000_0006,
+    0xD1FF_0000_0000_0000,
-    0xD1FF_0000_0000_000B,
+    0xD1FF_0000_0000_0002,
-    0xD1FF_0000_0000_0019,
+    0xD1FF_0000_0000_000A,
+    0xD1FF_0000_0000_0013,
+    0xD1FF_0000_0000_0017,
+    0xD1FF_0000_0000_001C,
+    0xD1FF_0000_0000_001F,
+    0xD1FF_0000_0000_0021,
+    0xD1FF_0000_0000_0024,
+    0xD1FF_0000_0000_0029,
+    0xD1FF_0000_0000_002E,
+    0xD1FF_0000_0000_0035,
+    0xD1FF_0000_0000_0045,
+    0xD1FF_0000_0000_0048,
+    0xD1FF_0000_0000_0049,
+    0xD1FF_0000_0000_004F,
+    0xD1FF_0000_0000_0062,
+    0xD1FF_0000_0000_006D,
+    0xD1FF_0000_0000_0074,
+    0xD1FF_0000_0000_0076,
     0xD1FF_0000_0000_0082,
-    0xD1FF_0000_0000_00CB,
+    0xD1FF_0000_0000_008F,
-    0xD1FF_0000_0000_00D5,
+    0xD1FF_0000_0000_0090,
-    0xD1FF_0000_0000_00D8,
+    0xD1FF_0000_0000_0097,
-    0xD1FF_0000_0000_00E8,
+    0xD1FF_0000_0000_009A,
-    0xD1FF_0000_0000_00EA,
+    0xD1FF_0000_0000_009F,
-    0xD1FF_0000_0000_00EB,
+    0xD1FF_0000_0000_00A5,
-    0xD1FF_0000_0000_00EC,
+    0xD1FF_0000_0000_00A8,
+    0xD1FF_0000_0000_00AD,
+    0xD1FF_0000_0000_00AE,
+    0xD1FF_0000_0000_00B8,
+    0xD1FF_0000_0000_00B9,
+    0xD1FF_0000_0000_00BC,
+    0xD1FF_0000_0000_00C5,
+    0xD1FF_0000_0000_00CA,
+    0xD1FF_0000_0000_00CE,
+    0xD1FF_0000_0000_00DE,
     0xD1FF_0000_0000_00ED,
-    0xD1FF_0000_0000_00F2,
+    0xD1FF_0000_0000_00EE,
-    0xD1FF_0000_0000_00F3,
+    0xD1FF_0000_0000_00EF,
-    0xD1FF_0000_0000_00F4,
-    0xD1FF_0000_0000_00FE,
-    0xD1FF_0000_0000_00FF,
-    0xD1FF_0000_0000_0102,
-    0xD1FF_0000_0000_0103,
-    0xD1FF_0000_0000_0104,
-    0xD1FF_0000_0000_0105,
-    0xD1FF_0000_0000_0106,
-    0xD1FF_0000_0000_0109,
-    0xD1FF_0000_0000_010B,
-    0xD1FF_0000_0000_010C,
-    0xD1FF_0000_0000_0110,
-    0xD1FF_0000_0000_0113,
-    0xD1FF_0000_0000_0114,
-    0xD1FF_0000_0000_011B,
-    0xD1FF_0000_0000_011C,
-    0xD1FF_0000_0000_011E,
-    0xD1FF_0000_0000_0120,
-    0xD1FF_0000_0000_0121,
-    0xD1FF_0000_0000_0122,
-    0xD1FF_0000_0000_0123,
-    0xD1FF_0000_0000_0124,
-    0xD1FF_0000_0000_0126,
-    0xD1FF_0000_0000_012B,
-    0xD1FF_0000_0000_012C,
-    0xD1FF_0000_0000_012E,
 ];
 
 /// 40 seeds proven winnable only within the Grandmaster budget (≤ 200 000 states).
 pub const GRANDMASTER_SEEDS: &[u64] = &[
-    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Grandmaster, date=2026-05-09)
+    // Generated by solitaire_assetgen::gen_difficulty_seeds (tier=Grandmaster, date=2026-06-04)
-    0xD1FF_0000_0000_0027,
+    0xD1FF_0000_0000_003C,
-    0xD1FF_0000_0000_00A0,
+    0xD1FF_0000_0000_0047,
-    0xD1FF_0000_0000_00C4,
+    0xD1FF_0000_0000_005A,
-    0xD1FF_0000_0000_00D4,
+    0xD1FF_0000_0000_009C,
-    0xD1FF_0000_0000_00DE,
+    0xD1FF_0000_0000_00D2,
-    0xD1FF_0000_0000_00F9,
+    0xD1FF_0000_0000_00F4,
-    0xD1FF_0000_0000_0107,
+    0xD1FF_0000_0000_00F6,
-    0xD1FF_0000_0000_0108,
+    0xD1FF_0000_0000_0104,
-    0xD1FF_0000_0000_0130,
+    0xD1FF_0000_0000_0106,
-    0xD1FF_0000_0000_0132,
+    0xD1FF_0000_0000_0111,
-    0xD1FF_0000_0000_0133,
+    0xD1FF_0000_0000_0112,
-    0xD1FF_0000_0000_0134,
+    0xD1FF_0000_0000_0116,
+    0xD1FF_0000_0000_0117,
+    0xD1FF_0000_0000_011A,
+    0xD1FF_0000_0000_0123,
+    0xD1FF_0000_0000_012B,
+    0xD1FF_0000_0000_012E,
     0xD1FF_0000_0000_0135,
-    0xD1FF_0000_0000_0137,
-    0xD1FF_0000_0000_0139,
     0xD1FF_0000_0000_013A,
-    0xD1FF_0000_0000_013D,
+    0xD1FF_0000_0000_013B,
-    0xD1FF_0000_0000_013F,
-    0xD1FF_0000_0000_0140,
     0xD1FF_0000_0000_0141,
-    0xD1FF_0000_0000_0142,
-    0xD1FF_0000_0000_0143,
-    0xD1FF_0000_0000_0145,
-    0xD1FF_0000_0000_0146,
     0xD1FF_0000_0000_014A,
     0xD1FF_0000_0000_014B,
-    0xD1FF_0000_0000_014C,
+    0xD1FF_0000_0000_014E,
-    0xD1FF_0000_0000_014D,
-    0xD1FF_0000_0000_014F,
     0xD1FF_0000_0000_0150,
-    0xD1FF_0000_0000_0151,
+    0xD1FF_0000_0000_0155,
-    0xD1FF_0000_0000_0152,
-    0xD1FF_0000_0000_0153,
     0xD1FF_0000_0000_0157,
     0xD1FF_0000_0000_0158,
-    0xD1FF_0000_0000_015B,
+    0xD1FF_0000_0000_0159,
+    0xD1FF_0000_0000_015A,
     0xD1FF_0000_0000_015C,
-    0xD1FF_0000_0000_015E,
+    0xD1FF_0000_0000_015D,
-    0xD1FF_0000_0000_0162,
+    0xD1FF_0000_0000_015F,
-    0xD1FF_0000_0000_0164,
+    0xD1FF_0000_0000_0166,
+    0xD1FF_0000_0000_0173,
+    0xD1FF_0000_0000_0174,
+    0xD1FF_0000_0000_0178,
+    0xD1FF_0000_0000_017D,
+    0xD1FF_0000_0000_0182,
+    0xD1FF_0000_0000_0187,
 ];
 
 // ---------------------------------------------------------------------------

solitaire_data/src/lib.rs

@@ -58,7 +58,7 @@ pub trait SyncProvider: Send + Sync {
     /// so backends without a server (e.g. `LocalOnlyProvider`) are
     /// silently no-op'd by the engine's push-on-win system, matching
     /// the same pattern `pull` / `push` follow.
-    async fn push_replay(&self, _replay: &crate::replay::Replay) -> Result<String, SyncError> {
+    async fn push_replay(&self, _replay: &Replay) -> Result<String, SyncError> {
         Err(SyncError::UnsupportedPlatform)
     }
 }
@@ -94,7 +94,7 @@ impl SyncProvider for Box<dyn SyncProvider + Send + Sync> {
     async fn delete_account(&self) -> Result<(), SyncError> {
         (**self).delete_account().await
     }
-    async fn push_replay(&self, replay: &crate::replay::Replay) -> Result<String, SyncError> {
+    async fn push_replay(&self, replay: &Replay) -> Result<String, SyncError> {
         (**self).push_replay(replay).await
     }
 }
@@ -118,8 +118,8 @@ pub use achievements::{
 
 pub mod progress;
 pub use progress::{
-    PlayerProgress, daily_seed_for, level_for_xp, load_progress_from, progress_file_path,
+    PlayerProgress, XpBreakdown, daily_seed_for, level_for_xp, load_progress_from,
-    save_progress_to, xp_for_win,
+    progress_file_path, save_progress_to, xp_breakdown, xp_for_win,
 };
 
 pub mod weekly;
@@ -143,27 +143,39 @@ pub use settings::{
     load_settings_from, save_settings_to, settings_file_path,
 };
 
+#[cfg(target_os = "android")]
+pub mod android_jni;
+
 #[cfg(target_os = "android")]
 mod android_keystore;
 
+#[cfg(not(target_arch = "wasm32"))]
 pub mod auth_tokens;
+#[cfg(not(target_arch = "wasm32"))]
 pub use auth_tokens::{
     TokenError, delete_tokens, load_access_token, load_refresh_token, store_tokens,
 };
 
 pub mod sync_client;
-pub use sync_client::{LocalOnlyProvider, SolitaireServerClient, provider_for_backend};
+pub use sync_client::LocalOnlyProvider;
+#[cfg(not(target_arch = "wasm32"))]
+pub use sync_client::{SolitaireServerClient, provider_for_backend};
 
 pub mod replay;
 pub use replay::{
     REPLAY_HISTORY_CAP, REPLAY_HISTORY_SCHEMA_VERSION, REPLAY_SCHEMA_VERSION, Replay,
-    ReplayHistory, ReplayMove, append_replay_to_history, load_replay_history_from,
+    ReplayHistory, append_replay_to_history, load_replay_history_from,
     migrate_legacy_latest_replay, replay_history_path, save_replay_history_to,
 };
+// `latest_replay_path` is still consumed by the engine's one-shot legacy
+// migration; `load_latest_replay_from`/`save_latest_replay_to` had no callers
+// outside `replay.rs` and were dropped from the public surface.
 #[allow(deprecated)]
-pub use replay::{latest_replay_path, load_latest_replay_from, save_latest_replay_to};
+pub use replay::latest_replay_path;
 
+#[cfg(not(target_arch = "wasm32"))]
 pub mod matomo_client;
+#[cfg(not(target_arch = "wasm32"))]
 pub use matomo_client::MatomoClient;
 
 pub mod platform;

solitaire_data/src/matomo_client.rs

@@ -114,3 +114,62 @@ fn url_encode(s: &str) -> String {
         })
         .collect()
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn pending(client: &MatomoClient) -> Vec<String> {
+        client.pending.lock().expect("pending lock").clone()
+    }
+
+    #[test]
+    fn event_buffers_encoded_matomo_query() {
+        let client = MatomoClient::new(
+            "https://analytics.example.com/",
+            7,
+            Some("alice bob".into()),
+        );
+
+        client.event("Game Flow", "Won+Fast", Some("draw three"), Some(42.5));
+
+        let pending = pending(&client);
+        assert_eq!(pending.len(), 1);
+        let query = &pending[0];
+        assert!(query.contains("idsite=7"));
+        assert!(query.contains("rec=1"));
+        assert!(query.contains("e_c=Game%20Flow"));
+        assert!(query.contains("e_a=Won%2BFast"));
+        assert!(query.contains("e_n=draw%20three"));
+        assert!(query.contains("e_v=42.5"));
+        assert!(query.contains("uid=alice%20bob"));
+    }
+
+    #[test]
+    fn event_buffer_drops_oldest_entries_when_capacity_exceeded() {
+        let client = MatomoClient::new("https://analytics.example.com", 1, None);
+
+        for idx in 0..101 {
+            client.event("Game", "Start", Some(&format!("event-{idx}")), None);
+        }
+
+        let pending = pending(&client);
+        assert_eq!(pending.len(), 51);
+        assert!(
+            pending[0].contains("event-50"),
+            "oldest retained event should be event-50, got {}",
+            pending[0]
+        );
+        assert!(
+            pending[50].contains("event-100"),
+            "newest retained event should be event-100, got {}",
+            pending[50]
+        );
+    }
+
+    #[test]
+    fn url_encode_leaves_unreserved_bytes_and_escapes_everything_else() {
+        assert_eq!(url_encode("AZaz09-_.~"), "AZaz09-_.~");
+        assert_eq!(url_encode("a b+c/d?"), "a%20b%2Bc%2Fd%3F");
+    }
+}

solitaire_data/src/platform.rs

@@ -55,7 +55,15 @@ pub fn data_dir() -> Option<PathBuf> {
     {
         Some(PathBuf::from(ANDROID_APP_FILES_DIR))
     }
-    #[cfg(not(target_os = "android"))]
+    #[cfg(target_arch = "wasm32")]
+    {
+        // No filesystem on the browser; all persistence goes through
+        // WasmStorage (localStorage-backed). Return None so every caller
+        // degrades gracefully (the same path they take on a
+        // misconfigured desktop environment).
+        None
+    }
+    #[cfg(all(not(target_os = "android"), not(target_arch = "wasm32")))]
     {
         dirs::data_dir()
     }

solitaire_data/src/progress.rs

@@ -25,12 +25,34 @@ pub fn daily_seed_for(date: NaiveDate) -> u64 {
     y * 10_000 + m * 100 + d
 }
 
-/// XP awarded for winning a game.
+/// Component breakdown of the XP awarded for a win.
+///
+/// This is the single source of truth for win-XP scoring: [`xp_for_win`] sums
+/// it for the total, and UI that displays the individual lines (the win-summary
+/// modal) reads the parts from here so the breakdown can never drift from the
+/// total.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct XpBreakdown {
+    /// Flat base XP granted for any win.
+    pub base: u64,
+    /// Scaled fast-win bonus (10..=50 for sub-2-minute wins, else 0).
+    pub speed_bonus: u64,
+    /// Bonus for winning without using undo (25, else 0).
+    pub no_undo_bonus: u64,
+}
+
+impl XpBreakdown {
+    /// Total XP awarded: `base + speed_bonus + no_undo_bonus`.
+    pub fn total(self) -> u64 {
+        self.base + self.speed_bonus + self.no_undo_bonus
+    }
+}
+
+/// Component breakdown of the XP awarded for a win.
 ///
 /// Base 50 + scaled fast-win bonus (10..=50 for sub-2-minute wins) + 25 if
 /// the player did not use undo.
-pub fn xp_for_win(time_seconds: u64, used_undo: bool) -> u64 {
+pub fn xp_breakdown(time_seconds: u64, used_undo: bool) -> XpBreakdown {
-    let base: u64 = 50;
     let speed_bonus: u64 = if time_seconds >= 120 {
         0
     } else {
@@ -39,8 +61,16 @@ pub fn xp_for_win(time_seconds: u64, used_undo: bool) -> u64 {
         let scaled = 50_u64.saturating_sub(time_seconds.saturating_mul(40) / 120);
         scaled.max(10)
     };
-    let no_undo_bonus: u64 = if used_undo { 0 } else { 25 };
+    XpBreakdown {
-    base + speed_bonus + no_undo_bonus
+        base: 50,
+        speed_bonus,
+        no_undo_bonus: if used_undo { 0 } else { 25 },
+    }
+}
+
+/// XP awarded for winning a game. See [`xp_breakdown`] for the components.
+pub fn xp_for_win(time_seconds: u64, used_undo: bool) -> u64 {
+    xp_breakdown(time_seconds, used_undo).total()
 }
 
 /// Platform-specific default path for `progress.json`.

solitaire_data/src/replay.rs

@@ -12,13 +12,22 @@
 //! carries any other version so older replays are silently dropped instead
 //! of crashing the loader.
 //!
-//! The recording is intentionally minimal — only [`ReplayMove`] entries
+//! The recording is intentionally minimal — only the
-//! that successfully advanced the game. `Undo` is **not** recorded: a
+//! [`KlondikeInstruction`](solitaire_core::KlondikeInstruction) inputs that
-//! replay represents the canonical path the player ultimately took to win,
+//! successfully advanced the game. `Undo` is **not** recorded: a replay
-//! so backed-out missteps simply do not appear in the move list. The
+//! represents the canonical path the player ultimately took to win, so
-//! starting deal is not stored either — the [`seed`](Replay::seed) +
+//! backed-out missteps simply do not appear in the move list. The starting
+//! deal is not stored either — the [`seed`](Replay::seed) +
 //! [`draw_mode`](Replay::draw_mode) + [`mode`](Replay::mode) are sufficient
 //! for `GameState::new_with_mode` to rebuild the identical layout.
+//!
+//! Each recorded move is the player's atomic *input*, not its outcome.
+//! `KlondikeInstruction::RotateStock` covers every click on the stock pile;
+//! the engine resolves draw-vs-recycle deterministically from the current
+//! stock state during playback, so the same input always produces the same
+//! effect on the same starting deal. Runtime-only pile-position types are
+//! never serialised — the instruction itself serialises via its compact
+//! upstream serde representation.
 
 use std::fs;
 use std::io;
@@ -26,8 +35,7 @@ use std::path::{Path, PathBuf};
 
 use chrono::NaiveDate;
 use serde::{Deserialize, Serialize};
-use solitaire_core::game_state::{DrawMode, GameMode};
+use solitaire_core::{DrawStockConfig, KlondikeInstruction, game_state::GameMode};
-use solitaire_core::pile::PileType;
 
 const LATEST_REPLAY_FILE_NAME: &str = "latest_replay.json";
 const REPLAY_HISTORY_FILE_NAME: &str = "replays.json";
@@ -65,14 +73,17 @@ fn history_schema_v0() -> u32 {
 /// seeing a broken one.
 ///
 /// History:
-/// - v1: initial release. `ReplayMove` had separate `Draw` and `Recycle`
+/// - v1: initial release. The move type had separate `Draw` and `Recycle`
 ///   variants which carried the *outcome* of a stock interaction rather
 ///   than the player's atomic input.
-/// - v2 (current): `Draw` + `Recycle` collapsed into a single `StockClick`
+/// - v2: `Draw` + `Recycle` collapsed into a single `StockClick` variant.
-///   variant. The engine resolves draw-vs-recycle deterministically from
+/// - v3 (current): the bespoke `ReplayMove` serde mirror was dropped. Moves
-///   the current stock state, so the input alone is sufficient and the
+///   are now stored directly as upstream
-///   replay model now stores atomic player inputs end-to-end.
+///   [`KlondikeInstruction`](solitaire_core::KlondikeInstruction) (compact
-pub const REPLAY_SCHEMA_VERSION: u32 = 2;
+///   int serde); `StockClick` is now `RotateStock`. Pile-position types are
+///   runtime-only and are never serialised. v1/v2 files fail to deserialise
+///   and are discarded by the loader.
+pub const REPLAY_SCHEMA_VERSION: u32 = 3;
 
 /// Default value for [`Replay::schema_version`] when deserialising files
 /// that pre-date the field. Any value other than [`REPLAY_SCHEMA_VERSION`]
@@ -81,32 +92,6 @@ fn schema_v0() -> u32 {
     0
 }
 
-/// One atomic player input recorded during a winning game, in the order
-/// it was applied to the live `GameState`.
-///
-/// `Undo` is intentionally absent — see the module-level docs.
-///
-/// The variants represent *inputs*, not outcomes. `StockClick` covers
-/// every player click on the stock pile; the engine then resolves
-/// draw-vs-recycle deterministically from the current state during both
-/// recording and playback, so the same input always produces the same
-/// effect on the same starting deal.
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub enum ReplayMove {
-    /// A successful `move_cards(from, to, count)` call.
-    Move {
-        /// Source pile.
-        from: PileType,
-        /// Destination pile.
-        to: PileType,
-        /// Number of cards moved.
-        count: usize,
-    },
-    /// A click on the stock pile. Resolves to a draw when stock is
-    /// non-empty and to a waste→stock recycle when stock is empty.
-    StockClick,
-}
-
 /// A complete recording of a single winning game.
 ///
 /// Replays are reconstructed by rebuilding a fresh
@@ -124,7 +109,7 @@ pub struct Replay {
     /// `GameState::new_with_mode(seed, draw_mode, mode)`.
     pub seed: u64,
     /// Draw mode the recorded game was played in.
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     /// Game mode the recorded game was played in.
     pub mode: GameMode,
     /// Total wall-clock seconds the win took. Used for the Stats UI
@@ -134,9 +119,11 @@ pub struct Replay {
     pub final_score: i32,
     /// ISO-8601 date the win was recorded.
     pub recorded_at: NaiveDate,
-    /// Ordered move list. Each entry is what the player did, replayable
+    /// Ordered move list. Each entry is the atomic
-    /// against a fresh `GameState` constructed from the seed.
+    /// [`KlondikeInstruction`](solitaire_core::KlondikeInstruction) the player
-    pub moves: Vec<ReplayMove>,
+    /// issued, replayable against a fresh `GameState` constructed from the
+    /// seed via `GameState::apply_instruction`.
+    pub moves: Vec<KlondikeInstruction>,
     /// Public share URL for this replay on the active sync backend, set
     /// by `sync_plugin::poll_replay_upload_result` when the upload
     /// task resolves. `None` when the player won on a local-only
@@ -180,12 +167,12 @@ impl Replay {
     /// latter directly when the upload task resolves.
     pub fn new(
         seed: u64,
-        draw_mode: DrawMode,
+        draw_mode: DrawStockConfig,
         mode: GameMode,
         time_seconds: u64,
         final_score: i32,
         recorded_at: NaiveDate,
-        moves: Vec<ReplayMove>,
+        moves: Vec<KlondikeInstruction>,
     ) -> Self {
         Self {
             schema_version: REPLAY_SCHEMA_VERSION,
@@ -442,6 +429,9 @@ pub fn migrate_legacy_latest_replay(latest_path: &Path, history_path: &Path) {
 #[allow(deprecated)]
 mod tests {
     use super::*;
+    use klondike::{
+        DstFoundation, DstTableau, Foundation, KlondikePile, KlondikePileStack, Tableau,
+    };
     use std::env;
 
     fn tmp_path(name: &str) -> PathBuf {
@@ -452,24 +442,22 @@ mod tests {
         let date = NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date");
         Replay::new(
             12345,
-            DrawMode::DrawThree,
+            DrawStockConfig::DrawThree,
             GameMode::Classic,
             134,
             5_120,
             date,
             vec![
-                ReplayMove::StockClick,
+                KlondikeInstruction::RotateStock,
-                ReplayMove::Move {
+                KlondikeInstruction::DstTableau(DstTableau {
-                    from: PileType::Waste,
+                    src: KlondikePileStack::Stock,
-                    to: PileType::Tableau(3),
+                    tableau: Tableau::Tableau4,
-                    count: 1,
+                }),
-                },
+                KlondikeInstruction::RotateStock,
-                ReplayMove::StockClick,
+                KlondikeInstruction::DstFoundation(DstFoundation {
-                ReplayMove::Move {
+                    src: KlondikePile::Tableau(Tableau::Tableau4),
-                    from: PileType::Tableau(3),
+                    foundation: Foundation::Foundation1,
-                    to: PileType::Foundation(0),
+                }),
-                    count: 1,
-                },
             ],
         )
     }
@@ -595,12 +583,12 @@ mod tests {
         let date = NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date");
         Replay::new(
             id as u64,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             60,
             id,
             date,
-            vec![ReplayMove::StockClick],
+            vec![KlondikeInstruction::RotateStock],
         )
     }
 
@@ -836,9 +824,11 @@ mod tests {
         let path = tmp_path("legacy_no_win_move_index");
         let _ = fs::remove_file(&path);
 
-        // Hand-rolled minimal v2 replay JSON with no win_move_index field.
+        // Hand-rolled minimal current-schema replay JSON with no
-        let v2_no_field = r#"{
+        // win_move_index field — the additive field must still default to None.
-            "schema_version": 2,
+        let no_field = format!(
+            r#"{{
+            "schema_version": {schema},
             "seed": 1,
             "draw_mode": "DrawOne",
             "mode": "Classic",
@@ -846,8 +836,10 @@ mod tests {
             "final_score": 100,
             "recorded_at": "2026-05-02",
             "moves": []
-        }"#;
+        }}"#,
-        fs::write(&path, v2_no_field).expect("write fixture");
+            schema = REPLAY_SCHEMA_VERSION,
+        );
+        fs::write(&path, no_field).expect("write fixture");
 
         let loaded = load_latest_replay_from(&path).expect("load");
         assert_eq!(loaded.win_move_index, None);

solitaire_data/src/settings.rs

@@ -9,7 +9,7 @@ use std::io;
 use std::path::{Path, PathBuf};
 
 use serde::{Deserialize, Serialize};
-use solitaire_core::game_state::{DifficultyLevel, DrawMode};
+use solitaire_core::{DrawStockConfig, game_state::DifficultyLevel};
 
 const SETTINGS_FILE_NAME: &str = "settings.json";
 
@@ -101,7 +101,7 @@ pub struct WindowGeometry {
 pub struct Settings {
     /// Draw mode selected for new games.
     #[serde(default = "default_draw_mode")]
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
     /// Linear SFX volume in `[0.0, 1.0]`. Applied to kira's SFX channel gain.
     #[serde(default = "default_sfx_volume")]
     pub sfx_volume: f32,
@@ -200,7 +200,7 @@ pub struct Settings {
     #[serde(default = "default_time_bonus_multiplier")]
     pub time_bonus_multiplier: f32,
     /// When `true`, the engine rejects new-game deals the
-    /// [`solitaire_core::solver`] cannot prove winnable, retrying
+    /// the solver cannot prove winnable, retrying
     /// fresh seeds up to [`SOLVER_DEAL_RETRY_CAP`] attempts before
     /// giving up and using the last tried seed. Off by default —
     /// the solver adds a few hundred milliseconds of latency on the
@@ -288,8 +288,8 @@ pub struct Settings {
     pub touch_input_mode: TouchInputMode,
 }
 
-fn default_draw_mode() -> DrawMode {
+fn default_draw_mode() -> DrawStockConfig {
-    DrawMode::DrawOne
+    DrawStockConfig::DrawOne
 }
 
 fn default_sfx_volume() -> f32 {
@@ -381,9 +381,9 @@ pub const REPLAY_MOVE_INTERVAL_STEP_SECS: f32 = 0.05;
 /// Maximum number of seed retries [`solitaire_engine::handle_new_game`]
 /// is willing to attempt before giving up and accepting the latest
 /// candidate seed when [`Settings::winnable_deals_only`] is on. If
-/// every retry comes back [`SolverResult::Unwinnable`] (which would
+/// every retry comes back provably unwinnable (`Ok(None)` from the
-/// be very unusual) we'd rather hand the player a possibly-unwinnable
+/// solver, which would be very unusual) we'd rather hand the player a
-/// deal than spin forever on the main thread.
+/// possibly-unwinnable deal than spin forever on the main thread.
 ///
 /// 50 attempts × ~50 ms median per solve = ~2.5 s worst-case stall —
 /// the upper bound on UI freeze when the toggle is on.
@@ -392,7 +392,7 @@ pub const SOLVER_DEAL_RETRY_CAP: u32 = 50;
 impl Default for Settings {
     fn default() -> Self {
         Self {
-            draw_mode: DrawMode::DrawOne,
+            draw_mode: DrawStockConfig::DrawOne,
             sfx_volume: default_sfx_volume(),
             music_volume: default_music_volume(),
             animation_speed: AnimSpeed::Normal,

solitaire_data/src/stats.rs

@@ -2,10 +2,10 @@
 //!
 //! [`StatsSnapshot`] is defined in `solitaire_sync` and re-exported here.
 //! This module adds the [`StatsExt`] extension trait, which supplies the
-//! `update_on_win` method that depends on [`DrawMode`] from `solitaire_core`.
+//! `update_on_win` method that depends on [`DrawStockConfig`] from `solitaire_core`.
 
 use chrono::Utc;
-use solitaire_core::game_state::{DrawMode, GameMode};
+use solitaire_core::{DrawStockConfig, game_state::GameMode};
 
 pub use solitaire_sync::StatsSnapshot;
 
@@ -18,9 +18,9 @@ pub trait StatsExt {
     ///
     /// Tracks lifetime totals only — per-mode best scores and times are
     /// updated separately via [`StatsExt::update_per_mode_bests`] so the
-    /// long-standing call sites that only know about [`DrawMode`] keep
+    /// long-standing call sites that only know about [`DrawStockConfig`] keep
     /// compiling.
-    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawMode);
+    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawStockConfig);
 
     /// Updates the per-mode best score and fastest-win-time fields for the
     /// given [`GameMode`]. Call alongside [`StatsExt::update_on_win`] from
@@ -37,7 +37,7 @@ pub trait StatsExt {
 }
 
 impl StatsExt for StatsSnapshot {
-    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawMode) {
+    fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawStockConfig) {
         let prev_wins = self.games_won;
         self.games_played += 1;
         self.games_won += 1;
@@ -64,8 +64,8 @@ impl StatsExt for StatsSnapshot {
         };
 
         match draw_mode {
-            DrawMode::DrawOne => self.draw_one_wins += 1,
+            DrawStockConfig::DrawOne => self.draw_one_wins += 1,
-            DrawMode::DrawThree => self.draw_three_wins += 1,
+            DrawStockConfig::DrawThree => self.draw_three_wins += 1,
         }
 
         self.last_modified = Utc::now();
@@ -135,7 +135,7 @@ mod tests {
     #[test]
     fn first_win_sets_all_fields() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(1500, 120, &DrawMode::DrawOne);
+        s.update_on_win(1500, 120, &DrawStockConfig::DrawOne);
         assert_eq!(s.games_played, 1);
         assert_eq!(s.games_won, 1);
         assert_eq!(s.win_streak_current, 1);
@@ -152,7 +152,7 @@ mod tests {
     fn streak_tracks_across_wins() {
         let mut s = StatsSnapshot::default();
         for _ in 0..3 {
-            s.update_on_win(100, 60, &DrawMode::DrawOne);
+            s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         }
         assert_eq!(s.win_streak_current, 3);
         assert_eq!(s.win_streak_best, 3);
@@ -161,8 +161,8 @@ mod tests {
     #[test]
     fn record_abandoned_resets_streak_and_increments_played() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.win_streak_current, 2);
         s.record_abandoned();
         assert_eq!(s.games_played, 3);
@@ -174,35 +174,35 @@ mod tests {
     #[test]
     fn fastest_win_takes_minimum() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 300, &DrawMode::DrawOne);
+        s.update_on_win(100, 300, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 120, &DrawMode::DrawOne);
+        s.update_on_win(100, 120, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 500, &DrawMode::DrawOne);
+        s.update_on_win(100, 500, &DrawStockConfig::DrawOne);
         assert_eq!(s.fastest_win_seconds, 120);
     }
 
     #[test]
     fn avg_time_is_correct_rolling_average() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 100, &DrawMode::DrawOne);
+        s.update_on_win(100, 100, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 200, &DrawMode::DrawOne);
+        s.update_on_win(100, 200, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 300, &DrawMode::DrawOne);
+        s.update_on_win(100, 300, &DrawStockConfig::DrawOne);
         assert_eq!(s.avg_time_seconds, 200);
     }
 
     #[test]
     fn best_score_updates_only_on_higher_score() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(500, 60, &DrawMode::DrawOne);
+        s.update_on_win(500, 60, &DrawStockConfig::DrawOne);
-        s.update_on_win(300, 60, &DrawMode::DrawOne);
+        s.update_on_win(300, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.best_single_score, 500);
-        s.update_on_win(800, 60, &DrawMode::DrawOne);
+        s.update_on_win(800, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.best_single_score, 800);
     }
 
     #[test]
     fn negative_score_treated_as_zero() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(-50, 60, &DrawMode::DrawOne);
+        s.update_on_win(-50, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.best_single_score, 0);
         assert_eq!(s.lifetime_score, 0);
     }
@@ -210,8 +210,8 @@ mod tests {
     #[test]
     fn draw_three_wins_tracked_separately() {
         let mut s = StatsSnapshot::default();
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
-        s.update_on_win(100, 60, &DrawMode::DrawThree);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawThree);
         assert_eq!(s.draw_one_wins, 1);
         assert_eq!(s.draw_three_wins, 1);
     }
@@ -221,7 +221,7 @@ mod tests {
         let mut s = StatsSnapshot::default();
         // Build a streak of 5.
         for _ in 0..5 {
-            s.update_on_win(100, 60, &DrawMode::DrawOne);
+            s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         }
         assert_eq!(s.win_streak_best, 5);
         // Lose (abandon), resetting current.
@@ -229,7 +229,7 @@ mod tests {
         assert_eq!(s.win_streak_current, 0);
         assert_eq!(s.win_streak_best, 5, "best must survive the loss");
         // Win once — current becomes 1, best must remain 5.
-        s.update_on_win(100, 60, &DrawMode::DrawOne);
+        s.update_on_win(100, 60, &DrawStockConfig::DrawOne);
         assert_eq!(s.win_streak_current, 1);
         assert_eq!(
             s.win_streak_best, 5,
@@ -243,7 +243,7 @@ mod tests {
             lifetime_score: u64::MAX - 100,
             ..Default::default()
         };
-        s.update_on_win(200, 60, &DrawMode::DrawOne);
+        s.update_on_win(200, 60, &DrawStockConfig::DrawOne);
         assert_eq!(
             s.lifetime_score,
             u64::MAX,

solitaire_data/src/storage.rs

@@ -3,13 +3,13 @@
 //! All saves go through `filename.json.tmp` → `rename()` so a crash or power
 //! loss during a write never corrupts the saved data.
 
+use chrono::Utc;
 use std::fs;
 use std::io;
 use std::path::{Path, PathBuf};
-use std::time::{SystemTime, UNIX_EPOCH};
 
 use serde::{Deserialize, Serialize};
-use solitaire_core::game_state::{GAME_STATE_SCHEMA_VERSION, GameState};
+use solitaire_core::game_state::GameState;
 
 use crate::stats::StatsSnapshot;
 
@@ -85,16 +85,13 @@ pub fn game_state_file_path() -> Option<PathBuf> {
 pub fn load_game_state_from(path: &Path) -> Option<GameState> {
     let data = fs::read(path).ok()?;
     let gs: GameState = serde_json::from_slice(&data).ok()?;
-    if gs.schema_version != GAME_STATE_SCHEMA_VERSION {
+    if gs.is_won() { None } else { Some(gs) }
-        return None;
-    }
-    if gs.is_won { None } else { Some(gs) }
 }
 
 /// Save an in-progress `GameState` atomically. Skips the write if `gs.is_won`
 /// because a completed game should not be resumed.
 pub fn save_game_state_to(path: &Path, gs: &GameState) -> io::Result<()> {
-    if gs.is_won {
+    if gs.is_won() {
         return Ok(());
     }
     if let Some(parent) = path.parent() {
@@ -234,9 +231,7 @@ pub fn load_time_attack_session_from_at(
 /// See [`load_time_attack_session_from_at`] for the rules under which
 /// the call returns `None` (missing file, corrupt JSON, expired window).
 pub fn load_time_attack_session_from(path: &Path) -> Option<TimeAttackSession> {
-    let now = SystemTime::now()
+    let now = Utc::now().timestamp().max(0) as u64;
-        .duration_since(UNIX_EPOCH)
-        .map_or(0, |d| d.as_secs());
     load_time_attack_session_from_at(path, now)
 }
 
@@ -254,9 +249,7 @@ pub fn delete_time_attack_session_at(path: &Path) -> io::Result<()> {
 /// current wall-clock time. Equivalent to constructing the struct
 /// manually and setting `saved_at_unix_secs` to `SystemTime::now()`.
 pub fn time_attack_session_with_now(remaining_secs: f32, wins: u32) -> TimeAttackSession {
-    let now = SystemTime::now()
+    let now = Utc::now().timestamp().max(0) as u64;
-        .duration_since(UNIX_EPOCH)
-        .map_or(0, |d| d.as_secs());
     TimeAttackSession {
         remaining_secs,
         wins,
@@ -286,7 +279,7 @@ fn cleanup_tmp_files_in(dir: &Path) {
 mod tests {
     use super::*;
     use crate::stats::{StatsExt, StatsSnapshot};
-    use solitaire_core::game_state::DrawMode;
+    use solitaire_core::DrawStockConfig;
     use std::env;
 
     fn tmp_path(name: &str) -> PathBuf {
@@ -299,7 +292,7 @@ mod tests {
         let _ = fs::remove_file(&path);
 
         let mut stats = StatsSnapshot::default();
-        stats.update_on_win(1000, 180, &DrawMode::DrawOne);
+        stats.update_on_win(1000, 180, &DrawStockConfig::DrawOne);
         save_stats_to(&path, &stats).expect("save");
 
         let loaded = load_stats_from(&path);
@@ -384,17 +377,17 @@ mod tests {
 
     #[test]
     fn game_state_round_trip() {
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::game_state::GameState;
         let path = gs_path("round_trip");
         let _ = fs::remove_file(&path);
 
-        let gs = GameState::new(12345, DrawMode::DrawOne);
+        let gs = GameState::new(12345, DrawStockConfig::DrawOne);
         save_game_state_to(&path, &gs).expect("save");
 
         let loaded = load_game_state_from(&path).expect("load");
         assert_eq!(loaded.seed, gs.seed);
-        assert_eq!(loaded.draw_mode, gs.draw_mode);
+        assert_eq!(loaded.draw_mode(), gs.draw_mode());
-        assert!(!loaded.is_won);
+        assert!(!loaded.is_won());
     }
 
     #[test]
@@ -413,12 +406,12 @@ mod tests {
 
     #[test]
     fn save_game_state_skips_won_games() {
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::game_state::GameState;
         let path = gs_path("won_skip");
         let _ = fs::remove_file(&path);
 
-        let mut gs = GameState::new(99, DrawMode::DrawOne);
+        let mut gs = GameState::new(99, DrawStockConfig::DrawOne);
-        gs.is_won = true;
+        gs.set_test_won(true);
         save_game_state_to(&path, &gs).expect("save should be no-op, not error");
         assert!(
             !path.exists(),
@@ -426,28 +419,11 @@ mod tests {
         );
     }
 
-    #[test]
-    fn load_game_state_ignores_won_games() {
-        use solitaire_core::game_state::{DrawMode, GameState};
-        let path = gs_path("won_load");
-        let _ = fs::remove_file(&path);
-
-        // Write a won game directly (bypassing save_game_state_to's guard).
-        let mut gs = GameState::new(77, DrawMode::DrawOne);
-        gs.is_won = true;
-        let json = serde_json::to_string_pretty(&gs).unwrap();
-        let tmp = path.with_extension("json.tmp");
-        fs::write(&tmp, json.as_bytes()).unwrap();
-        fs::rename(&tmp, &path).unwrap();
-
-        assert!(load_game_state_from(&path).is_none());
-    }
-
     #[test]
     fn delete_game_state_removes_file() {
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::game_state::GameState;
         let path = gs_path("delete");
-        let gs = GameState::new(1, DrawMode::DrawOne);
+        let gs = GameState::new(1, DrawStockConfig::DrawOne);
         save_game_state_to(&path, &gs).expect("save");
         assert!(path.exists());
         delete_game_state_at(&path).expect("delete");
@@ -463,9 +439,9 @@ mod tests {
 
     #[test]
     fn save_game_state_is_atomic() {
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::game_state::GameState;
         let path = gs_path("atomic");
-        let gs = GameState::new(55, DrawMode::DrawThree);
+        let gs = GameState::new(55, DrawStockConfig::DrawThree);
         save_game_state_to(&path, &gs).expect("save");
         let tmp = path.with_extension("json.tmp");
         assert!(!tmp.exists(), ".tmp must be cleaned up after rename");
@@ -516,6 +492,161 @@ mod tests {
         assert_eq!(loaded, StatsSnapshot::default());
     }
 
+    /// Schema v4 serialises the instruction history using upstream
+    /// `KlondikeInstruction` serde (named enum variants). The deserialiser
+    /// replays all `saved_moves` to reconstruct every pile.
+    ///
+    /// A fresh-game test (zero moves) never exercises that replay path, so this
+    /// test plays several real moves — including an undo — before saving.
+    ///
+    /// Since schema v5 no longer persists `score`/`undo_count`/`recycle_count`
+    /// (they are derived from the replayed session stats), round-trip fidelity is
+    /// verified by **re-save idempotency**: reloading the save and serialising it
+    /// again must reproduce byte-identical JSON. `undo_count` deliberately resets
+    /// to 0 on load because only the forward instruction history is persisted.
+    #[test]
+    fn game_state_v5_mid_game_round_trip() {
+        use solitaire_core::KlondikeInstruction;
+        use solitaire_core::game_state::GameState;
+
+        let path = gs_path("v4_mid_game");
+        let _ = fs::remove_file(&path);
+
+        let mut gs = GameState::new(42, DrawStockConfig::DrawOne);
+
+        // Draw several times to populate the instruction history with
+        // RotateStock entries and expose waste cards for further moves.
+        for _ in 0..6 {
+            if gs.draw().is_err() {
+                break;
+            }
+        }
+
+        // Execute the first available DstTableau or DstFoundation move so the
+        // instruction history contains a type other than RotateStock.
+        if let Some(instruction) = gs.possible_instructions().into_iter().find(|i| {
+            matches!(
+                i,
+                KlondikeInstruction::DstTableau(_) | KlondikeInstruction::DstFoundation(_)
+            )
+        }) {
+            let _ = gs.apply_instruction(instruction);
+        }
+
+        // Undo once: verifies that `undo_count` is persisted and that the
+        // truncated history (post-undo) replays back to the correct state.
+        if gs.undo_stack_len() > 0 {
+            let _ = gs.undo();
+        }
+
+        assert!(
+            gs.undo_stack_len() > 0,
+            "instruction history must be non-empty (seed 42 always produces draws)",
+        );
+
+        save_game_state_to(&path, &gs).expect("save");
+
+        // Verify the file carries the v5 schema marker.
+        let json = fs::read_to_string(&path).expect("read json");
+        assert!(
+            json.contains("\"schema_version\"") && json.contains('5'),
+            "saved file must use schema version 5",
+        );
+
+        let loaded = load_game_state_from(&path)
+            .expect("a valid in-progress game must load without error");
+
+        // The forward instruction history round-trips, so the reconstructed board
+        // re-serialises to byte-identical JSON.
+        let path_reload = gs_path("v5_mid_game_reload");
+        let _ = fs::remove_file(&path_reload);
+        save_game_state_to(&path_reload, &loaded).expect("re-save loaded");
+        assert_eq!(
+            fs::read_to_string(&path).expect("read original save"),
+            fs::read_to_string(&path_reload).expect("read re-saved"),
+            "re-saving the loaded game must reproduce the original save exactly",
+        );
+
+        // Derived board reads match the live game (move count + recycle count are
+        // both rebuilt from the replayed forward history).
+        assert_eq!(loaded.move_count(), gs.move_count(), "move_count round-trips");
+        assert_eq!(
+            loaded.recycle_count(),
+            gs.recycle_count(),
+            "recycle_count round-trips",
+        );
+        // undo_count is intentionally not persisted: it resets to 0 on load.
+        assert_eq!(
+            loaded.undo_count(),
+            0,
+            "undo_count resets across save/load under schema v5",
+        );
+    }
+
+    /// A schema v3 save (instruction history using the old u8-index mirror
+    /// types) is no longer loadable. The legacy migration path was dropped,
+    /// so any file claiming `schema_version: 3` must be rejected and the
+    /// player started on a fresh game.
+    #[test]
+    fn game_state_v3_is_rejected() {
+        let path = gs_path("v3_reject");
+        let _ = fs::remove_file(&path);
+
+        // Hand-crafted schema v3 JSON: one RotateStock (draw) instruction.
+        let v3_json = r#"{
+            "draw_mode": "DrawOne",
+            "mode": "Classic",
+            "score": 0,
+            "elapsed_seconds": 0,
+            "seed": 42,
+            "undo_count": 0,
+            "recycle_count": 0,
+            "take_from_foundation": true,
+            "schema_version": 3,
+            "saved_moves": ["RotateStock"]
+        }"#;
+        fs::write(&path, v3_json).expect("write v3 fixture");
+
+        assert!(
+            load_game_state_from(&path).is_none(),
+            "schema v3 must be rejected (no migration path)",
+        );
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Schema v2 stored raw pile arrays and undo snapshots (no instruction
+    /// history). Any file claiming `schema_version: 2` must be rejected so
+    /// players upgrading from an older build start with a fresh game rather
+    /// than a half-reconstructed state.
+    #[test]
+    fn save_format_v2_is_rejected() {
+        let path = gs_path("schema_v2");
+        let _ = fs::remove_file(&path);
+
+        // Structurally valid JSON for `PersistedGameState` but with
+        // `schema_version: 2`. The schema-version gate in
+        // `GameState::deserialize` must reject this before replay starts.
+        let v2_json = r#"{
+            "draw_mode": "DrawOne",
+            "mode": "Classic",
+            "score": 0,
+            "elapsed_seconds": 0,
+            "seed": 42,
+            "undo_count": 0,
+            "recycle_count": 0,
+            "take_from_foundation": true,
+            "schema_version": 2,
+            "saved_moves": []
+        }"#;
+        fs::write(&path, v2_json).expect("write v2 fixture");
+
+        assert!(
+            load_game_state_from(&path).is_none(),
+            "schema v2 game_state.json must be rejected — player must start a fresh game",
+        );
+    }
+
     // -----------------------------------------------------------------------
     // Time Attack session persistence
     //

solitaire_data/src/sync_client.rs

@@ -12,10 +12,14 @@
 //! without matching on [`SyncBackend`] anywhere else in the codebase.
 
 use async_trait::async_trait;
-use solitaire_sync::{ChallengeGoal, LeaderboardEntry, SyncPayload, SyncResponse};
+#[cfg(not(target_arch = "wasm32"))]
+use solitaire_sync::{ChallengeGoal, LeaderboardEntry};
+use solitaire_sync::{SyncPayload, SyncResponse};
 
+use crate::{SyncError, SyncProvider};
+
+#[cfg(not(target_arch = "wasm32"))]
 use crate::{
-    SyncError, SyncProvider,
     auth_tokens::{load_access_token, load_refresh_token, store_tokens},
     replay::Replay,
     settings::SyncBackend,
@@ -54,12 +58,17 @@ impl SyncProvider for LocalOnlyProvider {
 // ---------------------------------------------------------------------------
 // SolitaireServerClient
 // ---------------------------------------------------------------------------
+// Native-only: HTTP sync client and factory function.
+// On wasm32 these are gated out because reqwest uses native OS networking
+// (mio + hyper) which does not compile for wasm32-unknown-unknown.
+// ---------------------------------------------------------------------------
 
 /// HTTP sync client for the self-hosted Ferrous Solitaire server.
 ///
 /// Authenticates via JWT stored in the OS keychain. On a 401 response the
 /// client automatically attempts a token refresh and retries the request once
 /// before returning an error.
+#[cfg(not(target_arch = "wasm32"))]
 pub struct SolitaireServerClient {
     /// Base URL of the server, e.g. `"https://solitaire.example.com"`.
     /// Trailing slashes are stripped on construction.
@@ -70,6 +79,7 @@ pub struct SolitaireServerClient {
     client: reqwest::Client,
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 impl SolitaireServerClient {
     /// Construct a new client for the given server URL and username.
     ///
@@ -201,6 +211,7 @@ impl SolitaireServerClient {
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 #[async_trait]
 impl SyncProvider for SolitaireServerClient {
     /// Fetch the latest sync payload from the server.
@@ -486,6 +497,7 @@ impl SyncProvider for SolitaireServerClient {
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 impl SolitaireServerClient {
     /// Pulled out of `push_replay` so both the first attempt and the
     /// post-401-retry attempt go through the same parse path.
@@ -581,9 +593,10 @@ impl SolitaireServerClient {
 }
 
 // ---------------------------------------------------------------------------
-// Response extraction helpers
+// Response extraction helpers (native-only, use reqwest::Response)
 // ---------------------------------------------------------------------------
 
+#[cfg(not(target_arch = "wasm32"))]
 /// Deserialize a pull response body as [`SyncResponse`] and return its
 /// `merged` field, or map non-200 statuses to the appropriate [`SyncError`].
 ///
@@ -607,6 +620,7 @@ async fn extract_pull_body(resp: reqwest::Response) -> Result<SyncPayload, SyncE
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 /// Deserialize a leaderboard response body as `Vec<LeaderboardEntry>`.
 async fn extract_leaderboard_body(
     resp: reqwest::Response,
@@ -621,6 +635,7 @@ async fn extract_leaderboard_body(
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 /// Deserialize a push response body as [`SyncResponse`], or map non-200
 /// statuses to the appropriate [`SyncError`].
 ///
@@ -652,6 +667,7 @@ async fn extract_push_body(resp: reqwest::Response) -> Result<SyncResponse, Sync
 /// This is the **one** place in the codebase that matches on [`SyncBackend`]
 /// variants. All other code receives a `Box<dyn SyncProvider + Send + Sync>`
 /// and remains backend-agnostic.
+#[cfg(not(target_arch = "wasm32"))]
 pub fn provider_for_backend(backend: &SyncBackend) -> Box<dyn SyncProvider + Send + Sync> {
     match backend {
         SyncBackend::Local => Box::new(LocalOnlyProvider),

solitaire_data/src/weekly.rs

@@ -4,7 +4,7 @@
 //! increments matching counters in `PlayerProgress::weekly_goal_progress`.
 
 use chrono::{Datelike, NaiveDate};
-use solitaire_core::game_state::DrawMode;
+use solitaire_core::DrawStockConfig;
 
 /// XP awarded each time a weekly goal is just completed.
 pub const WEEKLY_GOAL_XP: u64 = 75;
@@ -36,7 +36,7 @@ pub struct WeeklyGoalDef {
 pub struct WeeklyGoalContext {
     pub time_seconds: u64,
     pub used_undo: bool,
-    pub draw_mode: DrawMode,
+    pub draw_mode: DrawStockConfig,
 }
 
 impl WeeklyGoalDef {
@@ -47,7 +47,7 @@ impl WeeklyGoalDef {
             WeeklyGoalKind::WinGame => true,
             WeeklyGoalKind::WinWithoutUndo => !ctx.used_undo,
             WeeklyGoalKind::WinUnder { seconds } => ctx.time_seconds < seconds,
-            WeeklyGoalKind::WinDrawThree => ctx.draw_mode == DrawMode::DrawThree,
+            WeeklyGoalKind::WinDrawThree => ctx.draw_mode == DrawStockConfig::DrawThree,
         }
     }
 }
@@ -106,7 +106,7 @@ mod tests {
         WeeklyGoalContext {
             time_seconds: time,
             used_undo: undo,
-            draw_mode: DrawMode::DrawOne,
+            draw_mode: DrawStockConfig::DrawOne,
         }
     }
 
@@ -114,7 +114,7 @@ mod tests {
         WeeklyGoalContext {
             time_seconds: time,
             used_undo: false,
-            draw_mode: DrawMode::DrawThree,
+            draw_mode: DrawStockConfig::DrawThree,
         }
     }
 

solitaire_engine/Cargo.toml

@@ -7,14 +7,11 @@ edition.workspace = true
 [dependencies]
 bevy           = { workspace = true }
 image          = { workspace = true }
-reqwest        = { workspace = true }
-kira           = { workspace = true }
 solitaire_core = { workspace = true }
 solitaire_data = { workspace = true }
 solitaire_sync = { workspace = true }
 chrono         = { workspace = true }
 uuid           = { workspace = true }
-tokio          = { workspace = true }
 serde          = { workspace = true }
 serde_json     = { workspace = true }
 thiserror      = { workspace = true }
@@ -22,17 +19,24 @@ usvg           = { workspace = true }
 resvg          = { workspace = true }
 tiny-skia      = { workspace = true }
 ron            = { workspace = true }
+
+# These deps are not available / not needed on wasm32:
+#   reqwest  — uses mio/hyper native networking (sync plugin is gated out)
+#   kira     — uses cpal OS audio (audio plugin is gated out)
+#   tokio    — multi-threaded runtime (TokioRuntimeResource is gated out)
+#   dirs     — platform data directories (storage uses WasmStorage instead)
+#   zip      — theme ZIP importer (importer is gated out on wasm32)
+#   arboard  — clipboard (no wasm backend; stats copy-link uses localStorage)
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+reqwest        = { workspace = true }
+kira           = { workspace = true }
+tokio          = { workspace = true }
 dirs           = { workspace = true }
 zip            = { workspace = true }
 
-# `arboard` provides clipboard access for the Stats overlay's
+# `arboard` has no Android backend and no wasm32 backend.  Gate it out for
-# "Copy share link" button. The crate has no Android backend
+# both; the copy-share-link button surfaces an informational toast instead.
-# (its `platform::Clipboard` module is unimplemented for the
+[target.'cfg(all(not(target_os = "android"), not(target_arch = "wasm32")))'.dependencies]
-# android target — `cargo apk build` fails with E0433 if this is
-# left unconditional). On Android the same button surfaces an
-# informational toast instead; see
-# `stats_plugin::handle_copy_share_link_button`.
-[target.'cfg(not(target_os = "android"))'.dependencies]
 arboard        = { workspace = true }
 
 [target.'cfg(target_os = "android")'.dependencies]
@@ -47,3 +51,7 @@ web-sys       = { version = "0.3", features = ["Storage", "Window"] }
 [dev-dependencies]
 async-trait = { workspace = true }
 tempfile    = { workspace = true }
+solitaire_core = { workspace = true, features = ["test-support"] }
+
+[lints]
+workspace = true

solitaire_engine/src/achievement_plugin.rs

@@ -116,7 +116,7 @@ impl Plugin for AchievementPlugin {
             // achievements-scroll system also runs cleanly under
             // `MinimalPlugins` in tests.
             .add_message::<MouseWheel>()
-            .add_message::<bevy::input::touch::TouchInput>()
+            .add_message::<TouchInput>()
             // Run after GameMutation (so GameWonEvent is available), after
             // StatsUpdate (so stats reflect this win), and after ProgressUpdate
             // (so daily_challenge_streak is up to date for daily_devotee).
@@ -176,9 +176,9 @@ fn evaluate_on_win(
             daily_challenge_streak: progress.0.daily_challenge_streak,
             last_win_score: ev.score,
             last_win_time_seconds: ev.time_seconds,
-            last_win_used_undo: game.0.undo_count > 0,
+            last_win_used_undo: game.0.undo_count() > 0,
             wall_clock_hour: Some(Local::now().hour()),
-            last_win_recycle_count: game.0.recycle_count,
+            last_win_recycle_count: game.0.recycle_count(),
             last_win_is_zen: game.0.mode == solitaire_core::game_state::GameMode::Zen,
         };
 
@@ -671,7 +671,7 @@ mod tests {
             .add_plugins(AchievementPlugin::headless());
         // StatsPlugin's UI toggle system reads ButtonInput<KeyCode>; under
         // MinimalPlugins it isn't auto-registered.
-        app.init_resource::<bevy::input::ButtonInput<KeyCode>>();
+        app.init_resource::<ButtonInput<KeyCode>>();
         app.update();
         app
     }
@@ -779,7 +779,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .undo_count = 1;
+            .force_test_undos(1);
 
         app.world_mut().write_message(GameWonEvent {
             score: 1000,
@@ -819,7 +819,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .draw_mode = solitaire_core::game_state::DrawMode::DrawThree;
+            .set_test_draw_mode(DrawStockConfig::DrawThree);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -868,7 +868,7 @@ mod tests {
         app.world_mut()
             .resource_mut::<GameStateResource>()
             .0
-            .draw_mode = solitaire_core::game_state::DrawMode::DrawThree;
+            .set_test_draw_mode(DrawStockConfig::DrawThree);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -912,7 +912,7 @@ mod tests {
         // Put the active game in Zen mode. evaluate_on_win reads
         // GameStateResource.mode directly to populate last_win_is_zen.
         app.world_mut().resource_mut::<GameStateResource>().0.mode =
-            solitaire_core::game_state::GameMode::Zen;
+            GameMode::Zen;
 
         app.world_mut().write_message(GameWonEvent {
             score: 0,
@@ -946,7 +946,7 @@ mod tests {
         // Default GameMode is Classic; assert and rely on it.
         assert_eq!(
             app.world().resource::<GameStateResource>().0.mode,
-            solitaire_core::game_state::GameMode::Classic
+            GameMode::Classic
         );
 
         app.world_mut().write_message(GameWonEvent {
@@ -1250,7 +1250,7 @@ mod tests {
             .add_plugins(crate::progress_plugin::ProgressPlugin::headless())
             .add_plugins(crate::settings_plugin::SettingsPlugin::headless())
             .add_plugins(AchievementPlugin::headless());
-        app.init_resource::<bevy::input::ButtonInput<KeyCode>>();
+        app.init_resource::<ButtonInput<KeyCode>>();
         app.update();
         app
     }
@@ -1393,8 +1393,8 @@ mod tests {
 
     use crate::replay_playback::ReplayPlaybackState;
     use chrono::NaiveDate;
-    use solitaire_core::game_state::{DrawMode, GameMode};
+    use solitaire_core::{DrawStockConfig, KlondikeInstruction, game_state::GameMode};
-    use solitaire_data::{Replay, ReplayMove};
+    use solitaire_data::Replay;
 
     /// Headless app variant that injects a default `ReplayPlaybackState`
     /// directly (no `ReplayPlaybackPlugin`) so we can drive the resource
@@ -1409,12 +1409,12 @@ mod tests {
     fn dummy_replay() -> Replay {
         Replay::new(
             1,
-            DrawMode::DrawOne,
+            DrawStockConfig::DrawOne,
             GameMode::Classic,
             10,
             100,
             NaiveDate::from_ymd_opt(2026, 5, 5).expect("valid date"),
-            vec![ReplayMove::StockClick],
+            vec![KlondikeInstruction::RotateStock],
         )
     }
 

solitaire_engine/src/analytics_plugin.rs

@@ -204,3 +204,61 @@ fn mode_str(mode: GameMode) -> &'static str {
         GameMode::Difficulty(_) => "difficulty",
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use solitaire_core::game_state::DifficultyLevel;
+
+    use super::*;
+
+    #[test]
+    fn client_for_requires_analytics_opt_in() {
+        let settings = Settings {
+            analytics_enabled: false,
+            matomo_url: Some("https://analytics.example.com".into()),
+            ..Settings::default()
+        };
+
+        assert!(client_for(&settings).is_none());
+    }
+
+    #[test]
+    fn client_for_requires_matomo_url() {
+        let settings = Settings {
+            analytics_enabled: true,
+            matomo_url: None,
+            ..Settings::default()
+        };
+
+        assert!(client_for(&settings).is_none());
+    }
+
+    #[test]
+    fn client_for_creates_client_when_enabled_and_configured() {
+        let settings = Settings {
+            analytics_enabled: true,
+            matomo_url: Some("https://analytics.example.com".into()),
+            matomo_site_id: 2,
+            sync_backend: SyncBackend::SolitaireServer {
+                url: "https://solitaire.example.com".into(),
+                username: "alice".into(),
+                avatar_url: None,
+            },
+            ..Settings::default()
+        };
+
+        assert!(client_for(&settings).is_some());
+    }
+
+    #[test]
+    fn mode_labels_match_analytics_payload_contract() {
+        assert_eq!(mode_str(GameMode::Classic), "classic");
+        assert_eq!(mode_str(GameMode::Zen), "zen");
+        assert_eq!(mode_str(GameMode::Challenge), "challenge");
+        assert_eq!(mode_str(GameMode::TimeAttack), "time_attack");
+        assert_eq!(
+            mode_str(GameMode::Difficulty(DifficultyLevel::Grandmaster)),
+            "difficulty"
+        );
+    }
+}

solitaire_engine/src/android_clipboard.rs

@@ -1,37 +1,19 @@
 /// Android clipboard bridge via JNI.
 ///
 /// Writes text to the system clipboard by calling into `ClipboardManager`
-/// through the JNI. Only compiled and linked on `target_os = "android"`.
+/// through the safe [`solitaire_data::android_jni`] bridge. Only compiled and
+/// linked on `target_os = "android"`.
 #[cfg(target_os = "android")]
 pub fn set_text(text: &str) -> Result<(), String> {
-    use bevy::android::ANDROID_APP;
+    use jni::objects::JValueOwned;
-    use jni::{
+    use solitaire_data::android_jni;
-        JavaVM,
-        objects::{JObject, JValueOwned},
-    };
 
-    let app = ANDROID_APP
+    android_jni::with_activity_env(|env, activity| {
-        .get()
-        .ok_or_else(|| "ANDROID_APP not initialized".to_string())?;
-
-    // SAFETY: vm_as_ptr() returns the raw JavaVM* set up by the Android runtime.
-    let vm = unsafe { JavaVM::from_raw(app.vm_as_ptr().cast()) }
-        .map_err(|e| format!("JavaVM::from_raw: {e}"))?;
-
-    let mut env = vm
-        .attach_current_thread_permanently()
-        .map_err(|e| format!("attach_current_thread: {e}"))?;
-
-    // SAFETY: activity_as_ptr() is the NativeActivity jobject pointer —
-    // valid for the lifetime of the process.
-    let activity = unsafe { JObject::from_raw(app.activity_as_ptr() as _) };
-
-    (|| -> jni::errors::Result<()> {
         // ClipboardManager cm = activity.getSystemService("clipboard")
         let svc_name = JValueOwned::from(env.new_string("clipboard")?);
         let cm = env
             .call_method(
-                &activity,
+                activity,
                 "getSystemService",
                 "(Ljava/lang/String;)Ljava/lang/Object;",
                 &[svc_name.borrow()],
@@ -60,6 +42,5 @@ pub fn set_text(text: &str) -> Result<(), String> {
             &[clip_val.borrow()],
         )?
         .v()
-    })()
+    })
-    .map_err(|e| format!("clipboard JNI: {e}"))
 }

solitaire_engine/src/animation_plugin.rs

@@ -13,6 +13,7 @@
 use std::collections::VecDeque;
 
 use bevy::prelude::*;
+use bevy::window::RequestRedraw;
 use solitaire_data::{AnimSpeed, Settings};
 
 use crate::achievement_plugin::display_name_for;
@@ -180,6 +181,7 @@ impl Plugin for AnimationPlugin {
             .add_message::<MoveRejectedEvent>()
             .add_message::<WarningToastEvent>()
             .add_message::<XpAwardedEvent>()
+            .add_message::<RequestRedraw>()
             .init_resource::<EffectiveSlideDuration>()
             .init_resource::<ToastQueue>()
             .init_resource::<ActiveToast>()
@@ -352,7 +354,7 @@ fn handle_win_cascade(
             end: target.truncate(),
             elapsed: 0.0,
             duration,
-            curve: crate::card_animation::MotionCurve::Expressive,
+            curve: MotionCurve::Expressive,
             delay: i as f32 * step,
             start_z: start.z,
             end_z: target.z,
@@ -1076,7 +1078,7 @@ mod tests {
         // Pairs the existing audio (`card_invalid.wav`) and visual
         // (`feedback_anim_plugin::queue_shake_for_rejected_move`) feedback
         // with an accessibility-focused readable text cue.
-        use solitaire_core::pile::PileType;
+        use solitaire_core::{KlondikePile, Tableau};
         let mut app = App::new();
         app.add_plugins(MinimalPlugins).add_plugins(AnimationPlugin);
 
@@ -1088,8 +1090,8 @@ mod tests {
             .count();
 
         app.world_mut().write_message(MoveRejectedEvent {
-            from: PileType::Tableau(0),
+            from: KlondikePile::Tableau(Tableau::Tableau1),
-            to: PileType::Tableau(1),
+            to: KlondikePile::Tableau(Tableau::Tableau2),
             count: 1,
         });
         app.update();

solitaire_engine/src/assets/card_face_svg.rs

@@ -22,7 +22,7 @@
 //! red/black colour split.
 
 use bevy::math::UVec2;
-use solitaire_core::card::{Rank, Suit};
+use solitaire_core::{Rank, Suit};
 
 /// Target rasterisation size in pixels (2:3 aspect, half the default
 /// `SvgLoaderSettings` resolution).

solitaire_engine/src/assets/sources.rs

@@ -47,12 +47,16 @@
 //! comments on each call out the pairing so a future reader doesn't
 //! accidentally drop one half.
 
+#[cfg(not(target_arch = "wasm32"))]
 use bevy::asset::AssetApp;
+#[cfg(not(target_arch = "wasm32"))]
 use bevy::asset::io::AssetSourceBuilder;
 use bevy::asset::io::embedded::EmbeddedAssetRegistry;
+#[cfg(not(target_arch = "wasm32"))]
 use bevy::asset::io::file::FileAssetReader;
 use bevy::prelude::*;
 
+#[cfg(not(target_arch = "wasm32"))]
 use crate::assets::user_dir::user_theme_dir;
 
 /// `AssetSourceId` of the user-themes asset source. Use it as
@@ -111,6 +115,10 @@ macro_rules! embed_classic_svg {
 }
 
 /// Every Dark-theme SVG file bundled into the binary.
+// The `as &[u8]` in `embed_dark_svg!` coerces each fixed-size
+// `&[u8; N]` (N varies per file) to a uniform `&[u8]` so the tuples fit
+// this array type. The cast is load-bearing, not trivial.
+#[allow(trivial_casts)]
 const DARK_THEME_SVGS: &[(&str, &[u8])] = &[
     embed_dark_svg!("back.svg"),
     embed_dark_svg!("clubs_ace.svg"),
@@ -168,6 +176,8 @@ const DARK_THEME_SVGS: &[(&str, &[u8])] = &[
 ];
 
 /// Every Classic-theme SVG file bundled into the binary.
+// See `DARK_THEME_SVGS`: the `as &[u8]` cast is load-bearing.
+#[allow(trivial_casts)]
 const CLASSIC_THEME_SVGS: &[(&str, &[u8])] = &[
     embed_classic_svg!("back.svg"),
     embed_classic_svg!("clubs_ace.svg"),
@@ -235,11 +245,16 @@ const CLASSIC_THEME_SVGS: &[(&str, &[u8])] = &[
 /// Returns the `&mut App` so the call can be chained from the binary
 /// entry point.
 pub fn register_theme_asset_sources(app: &mut App) -> &mut App {
+    // User themes are stored on the filesystem; wasm32 has no filesystem and
+    // `FileAssetReader` is not available on that target.
+    #[cfg(not(target_arch = "wasm32"))]
+    {
         let root = user_theme_dir();
         app.register_asset_source(
             USER_THEMES,
             AssetSourceBuilder::new(move || Box::new(FileAssetReader::new(root.clone()))),
         );
+    }
     app
 }
 

solitaire_engine/src/assets/svg_loader.rs

@@ -192,7 +192,7 @@ fn shared_fontdb() -> Arc<fontdb::Database> {
 fn bundled_font_resolver() -> usvg::FontResolver<'static> {
     use usvg::FontResolver;
 
-    usvg::FontResolver {
+    FontResolver {
         select_font: Box::new(|_font, db| db.faces().next().map(|face| face.id)),
         select_fallback: FontResolver::default_fallback_selector(),
     }
@@ -282,7 +282,7 @@ mod tests {
     /// tightens.
     #[test]
     fn settings_satisfies_loader_bounds() {
-        fn assert_loader_settings<T: Default + serde::Serialize + serde::de::DeserializeOwned>() {}
+        fn assert_loader_settings<T: Default + Serialize + serde::de::DeserializeOwned>() {}
         assert_loader_settings::<SvgLoaderSettings>();
     }
 }

solitaire_engine/src/assets/user_dir.rs

@@ -82,6 +82,15 @@ fn user_theme_dir_for(data_dir: PathBuf) -> PathBuf {
 /// the panic message names the supported workaround.
 fn detected_platform_data_dir() -> PathBuf {
     solitaire_data::data_dir().unwrap_or_else(|| {
+        // On wasm32, data_dir() always returns None — there is no filesystem.
+        // User themes are not supported in the browser build; return an empty
+        // path so callers produce a benign empty dir rather than panicking.
+        #[cfg(target_arch = "wasm32")]
+        {
+            PathBuf::new()
+        }
+        #[cfg(not(target_arch = "wasm32"))]
+        {
             panic!(
                 "user_theme_dir(): platform data directory is unavailable. \
                  On Linux check $XDG_DATA_HOME or $HOME; on macOS / Windows \
@@ -89,6 +98,7 @@ fn detected_platform_data_dir() -> PathBuf {
                  As a workaround call solitaire_engine::assets::user_dir::\
                  set_user_theme_dir() before App::run()."
             )
+        }
     })
 }
 

solitaire_engine/src/audio_plugin.rs

@@ -34,7 +34,6 @@ use crate::events::{
 use crate::pause_plugin::PausedResource;
 use crate::resources::GameStateResource;
 use crate::settings_plugin::{SettingsChangedEvent, SettingsResource};
-use solitaire_core::pile::PileType;
 
 /// Volume amplitude for the stock-recycle draw sound (half of normal 1.0).
 const RECYCLE_VOLUME: f64 = 0.5;
@@ -374,10 +373,7 @@ fn play_on_draw(
         // When the stock pile is empty the draw action recycles the waste pile
         // back to stock. Play the flip sound at half volume to give audible
         // feedback that distinguishes a recycle from a normal draw.
-        let stock_len = game
+        let stock_len = game.as_ref().map_or(1, |g| g.0.stock_cards().len()); // default > 0 → normal draw sound
-            .as_ref()
-            .and_then(|g| g.0.piles.get(&PileType::Stock))
-            .map_or(1, |p| p.cards.len()); // default > 0 → normal draw sound
 
         if is_recycle(stock_len) {
             let mut data = lib.flip.clone();

solitaire_engine/src/auto_complete_plugin.rs

@@ -9,7 +9,9 @@
 //! returns `None` (e.g. a transient state), the plugin retries next tick.
 
 use bevy::prelude::*;
+use bevy::window::RequestRedraw;
 
+#[cfg(not(target_arch = "wasm32"))]
 use crate::audio_plugin::{AudioState, SoundLibrary};
 use crate::events::{MoveRequestEvent, StateChangedEvent};
 use crate::game_plugin::GameMutation;
@@ -20,11 +22,18 @@ use crate::resources::GameStateResource;
 ///
 /// Plays the win fanfare at half volume so it is clearly distinguishable from
 /// both normal card-place sounds and the full win fanfare that fires later.
+#[cfg(not(target_arch = "wasm32"))]
 const AUTO_COMPLETE_CHIME_VOLUME: f64 = 0.5;
 
 /// Seconds between consecutive auto-complete moves.
 const STEP_INTERVAL: f32 = 0.12;
 
+/// Seconds to wait after detection before firing the first auto-complete move.
+///
+/// This pause gives the player a moment to register that the game is
+/// transitioning into auto-complete mode before cards start moving.
+const AUTO_COMPLETE_INITIAL_DELAY: f32 = 0.75;
+
 /// Tracks whether auto-complete is active and when the next move fires.
 #[derive(Resource, Default, Debug)]
 pub struct AutoCompleteState {
@@ -39,7 +48,9 @@ pub struct AutoCompletePlugin;
 
 impl Plugin for AutoCompletePlugin {
     fn build(&self, app: &mut App) {
-        app.init_resource::<AutoCompleteState>().add_systems(
+        app.init_resource::<AutoCompleteState>()
+            .add_message::<RequestRedraw>()
+            .add_systems(
                 Update,
                 (
                     detect_auto_complete,
@@ -65,21 +76,28 @@ fn detect_auto_complete(
     }
     changed.clear();
 
-    if game.0.is_won {
+    if game.0.is_won() {
         state.active = false;
         return;
     }
-    if game.0.is_auto_completable && !state.active {
+    if game.0.is_auto_completable() && !state.active {
         state.active = true;
-        state.cooldown = 0.0; // fire first move immediately
+        state.cooldown = AUTO_COMPLETE_INITIAL_DELAY;
+    } else if !game.0.is_auto_completable() && state.active {
+        // `is_auto_completable` only becomes false after an explicit undo
+        // (which puts a card back on the tableau or re-fills the stock/waste)
+        // or a new-game reset — never as a transient gap during a normal
+        // auto-complete sequence.  Deactivate here so `drive_auto_complete`
+        // does not keep retrying indefinitely after the player undoes out of
+        // the sequence.
+        //
+        // Note: the transient-`None` case mentioned in older versions of this
+        // comment referred to `next_auto_complete_move()` returning `None`, not
+        // to `is_auto_completable` being false.  Those are independent fields;
+        // `drive_auto_complete` still retries on a transient `None` return from
+        // `next_auto_complete_move` because that check happens there, not here.
+        state.active = false;
     }
-    // Intentionally no `else if !is_auto_completable` branch here.
-    // Deactivating on every frame where `is_auto_completable` is false
-    // would hard-stop the sequence mid-flight whenever `next_auto_complete_move`
-    // transiently returns `None` (e.g. while the previous move is still
-    // in-flight). The `is_won` check above already handles the definitive
-    // end-of-game case; `drive_auto_complete` simply retries next tick
-    // when no move is available yet.
 }
 
 /// Plays a distinct chime the moment auto-complete first activates.
@@ -88,6 +106,7 @@ fn detect_auto_complete(
 /// exactly once on the `false → true` edge. The win fanfare is played at half
 /// volume (`AUTO_COMPLETE_CHIME_VOLUME`) so it is clearly recognisable but does
 /// not overwhelm the card-place sounds that follow immediately.
+#[cfg(not(target_arch = "wasm32"))]
 fn on_auto_complete_start(
     state: Res<AutoCompleteState>,
     mut was_active: Local<bool>,
@@ -108,6 +127,12 @@ fn on_auto_complete_start(
     audio.play_sfx_at_volume(&lib.fanfare, AUTO_COMPLETE_CHIME_VOLUME);
 }
 
+// No audio on wasm — stub keeps the system registration unconditional.
+#[cfg(target_arch = "wasm32")]
+fn on_auto_complete_start(state: Res<AutoCompleteState>, mut was_active: Local<bool>) {
+    *was_active = state.active;
+}
+
 /// Fires one `MoveRequestEvent` per `STEP_INTERVAL` while auto-complete is active.
 fn drive_auto_complete(
     mut state: ResMut<AutoCompleteState>,
@@ -142,9 +167,9 @@ mod tests {
     use super::*;
     use crate::game_plugin::GamePlugin;
     use crate::table_plugin::TablePlugin;
-    use solitaire_core::card::{Card, Rank, Suit};
+    use solitaire_core::{Foundation, KlondikePile, Tableau};
-    use solitaire_core::game_state::{DrawMode, GameState};
+    use solitaire_core::{Deck, Rank, Suit};
-    use solitaire_core::pile::PileType;
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -152,36 +177,45 @@ mod tests {
             .add_plugins(GamePlugin)
             .add_plugins(TablePlugin)
             .add_plugins(AutoCompletePlugin);
-        app.init_resource::<bevy::input::ButtonInput<KeyCode>>();
+        app.init_resource::<ButtonInput<KeyCode>>();
         app.update();
         app
     }
 
-    /// Build a nearly-won game: one Ace of Clubs in Tableau(0), all other
+    fn seeded_state_with_auto_move() -> (GameState, (KlondikePile, KlondikePile)) {
-    /// tableau piles empty, stock/waste empty, Clubs foundation empty.
+        let mut g = GameState::new(1, DrawStockConfig::DrawOne);
-    fn nearly_won_state() -> GameState {
+        g.set_test_stock_cards(Vec::new());
-        let mut g = GameState::new(42, DrawMode::DrawOne);
+        g.set_test_waste_cards(Vec::new());
-        g.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        for foundation in [
-        g.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+            Foundation::Foundation1,
-        for i in 0..7 {
+            Foundation::Foundation2,
-            g.piles
+            Foundation::Foundation3,
-                .get_mut(&PileType::Tableau(i))
+            Foundation::Foundation4,
-                .unwrap()
+        ] {
-                .cards
+            g.set_test_foundation_cards(foundation, Vec::new());
-                .clear();
         }
-        g.piles
+        for tableau in [
-            .get_mut(&PileType::Tableau(0))
+            Tableau::Tableau1,
-            .unwrap()
+            Tableau::Tableau2,
-            .cards
+            Tableau::Tableau3,
-            .push(Card {
+            Tableau::Tableau4,
-                id: 99,
+            Tableau::Tableau5,
-                suit: Suit::Clubs,
+            Tableau::Tableau6,
-                rank: Rank::Ace,
+            Tableau::Tableau7,
-                face_up: true,
+        ] {
-            });
+            g.set_test_tableau_cards(tableau, Vec::new());
-        g.is_auto_completable = true;
+        }
-        g
+        g.set_test_tableau_cards(
+            Tableau::Tableau1,
+            vec![solitaire_core::Card::new(Deck::Deck1, Suit::Clubs, Rank::Ace)],
+        );
+        g.set_test_auto_completable(true);
+        let expected = (
+            KlondikePile::Tableau(Tableau::Tableau1),
+            KlondikePile::Foundation(Foundation::Foundation1),
+        );
+        assert_eq!(g.next_auto_complete_move(), Some(expected));
+        (g, expected)
     }
 
     #[test]
@@ -193,8 +227,9 @@ mod tests {
     #[test]
     fn detect_activates_when_auto_completable() {
         let mut app = headless_app();
-        // Install a nearly-won state and fire StateChangedEvent.
+        let mut g = GameState::new(42, DrawStockConfig::DrawOne);
-        app.world_mut().resource_mut::<GameStateResource>().0 = nearly_won_state();
+        g.set_test_auto_completable(true);
+        app.world_mut().resource_mut::<GameStateResource>().0 = g;
         app.world_mut().write_message(StateChangedEvent);
         app.update();
 
@@ -204,9 +239,14 @@ mod tests {
     #[test]
     fn drive_fires_move_request_when_active() {
         let mut app = headless_app();
-        app.world_mut().resource_mut::<GameStateResource>().0 = nearly_won_state();
+        let (g, (expected_from, expected_to)) = seeded_state_with_auto_move();
+        app.world_mut().resource_mut::<GameStateResource>().0 = g;
         app.world_mut().write_message(StateChangedEvent);
         app.update(); // detect runs, sets active
+
+        // Zero out the cooldown so drive fires on the next update regardless
+        // of the initial delay constant.
+        app.world_mut().resource_mut::<AutoCompleteState>().cooldown = 0.0;
         app.update(); // drive fires the move
 
         let events = app.world().resource::<Messages<MoveRequestEvent>>();
@@ -214,17 +254,16 @@ mod tests {
         let fired: Vec<_> = cursor.read(events).collect();
         // At least one MoveRequestEvent should have been fired.
         assert!(!fired.is_empty(), "expected at least one MoveRequestEvent");
-        assert_eq!(fired[0].from, PileType::Tableau(0));
+        assert_eq!(fired[0].from, expected_from);
-        // First empty foundation slot wins on a fresh nearly-won board.
+        assert_eq!(fired[0].to, expected_to);
-        assert_eq!(fired[0].to, PileType::Foundation(0));
     }
 
     #[test]
     fn drive_deactivates_on_win() {
         let mut app = headless_app();
         // Inject a won game state — active should not be set.
-        let mut gs = nearly_won_state();
+        let (mut gs, _) = seeded_state_with_auto_move();
-        gs.is_won = true;
+        gs.set_test_won(true);
         app.world_mut().resource_mut::<GameStateResource>().0 = gs;
         app.world_mut().write_message(StateChangedEvent);
         app.update();

solitaire_engine/src/avatar_plugin.rs

@@ -36,7 +36,7 @@ pub struct AvatarFetchEvent {
     pub url: String,
 }
 
-impl bevy::prelude::Message for AvatarFetchEvent {}
+impl Message for AvatarFetchEvent {}
 
 /// In-flight avatar download task. Returns the raw image bytes on success,
 /// or `None` on any network / decode error.

solitaire_engine/src/card_animation/interaction.rs

@@ -33,6 +33,7 @@ use std::collections::VecDeque;
 
 use bevy::prelude::*;
 use bevy::window::PrimaryWindow;
+use solitaire_core::Card;
 
 use super::animation::CardAnimation;
 use super::tuning::AnimationTuning;
@@ -72,7 +73,7 @@ pub struct HoverState {
 #[derive(Debug, Clone)]
 pub enum BufferedInput {
     Move {
-        from: crate::events::MoveRequestEvent,
+        from: MoveRequestEvent,
     },
     Draw,
     Undo,
@@ -210,12 +211,12 @@ pub(crate) fn apply_drag_visual(
 
     // Only lift cards that are in a *committed* drag. Pending drags (below
     // threshold) must stay at scale 1.0 to avoid visible premature lift.
-    let (dragged_ids, committed): (&[u32], bool) = drag
+    let (dragged_cards, committed): (&[Card], bool) = drag
         .as_ref()
         .map_or((&[], false), |d| (d.cards.as_slice(), d.committed));
 
     for (_, card, mut transform) in &mut cards {
-        let is_active_drag = committed && dragged_ids.contains(&card.card_id);
+        let is_active_drag = committed && dragged_cards.contains(&card.card);
         let target_scale = if is_active_drag { drag_scale } else { 1.0 };
         let current = transform.scale.x;
         let new_scale = current + (target_scale - current) * (DRAG_LERP_SPEED * dt).min(1.0);

solitaire_engine/src/card_animation/mod.rs

@@ -92,6 +92,7 @@ pub use timing::{
 pub use tuning::{AnimationTuning, InputPlatform};
 
 use bevy::prelude::*;
+use bevy::window::RequestRedraw;
 
 use crate::card_plugin::CardEntity;
 use crate::events::{DrawRequestEvent, GameWonEvent, MoveRequestEvent, UndoRequestEvent};
@@ -125,6 +126,7 @@ impl Plugin for CardAnimationPlugin {
             .add_message::<DrawRequestEvent>()
             .add_message::<UndoRequestEvent>()
             .add_message::<GameWonEvent>()
+            .add_message::<RequestRedraw>()
             .init_resource::<DragState>()
             .init_resource::<HoverState>()
             .init_resource::<InputBuffer>()

solitaire_engine/src/card_animation/tuning.rs

@@ -100,7 +100,7 @@ impl AnimationTuning {
             platform: InputPlatform::Mouse,
             duration_scale: 1.0,
             overshoot_scale: 1.0,
-            drag_threshold_px: 4.0,
+            drag_threshold_px: 6.0,
             drag_scale: 1.08,
             hover_scale: 1.04,
             hover_lerp_speed: 14.0,

solitaire_engine/src/card_plugin/anim.rs

@@ -0,0 +1,200 @@
+//! Card flip animation and drag shadows.
+
+use super::*;
+
+use std::collections::HashSet;
+
+use solitaire_core::Card;
+
+use crate::animation_plugin::EffectiveSlideDuration;
+use crate::events::{CardFaceRevealedEvent, CardFlippedEvent};
+use crate::layout::LayoutResource;
+use crate::resources::DragState;
+use crate::ui_theme::{
+    CARD_SHADOW_ALPHA_DRAG, CARD_SHADOW_COLOR, CARD_SHADOW_LOCAL_Z,
+};
+
+/// Listens for `CardFlippedEvent` and inserts a `CardFlipAnim` on the entity.
+///
+/// Skipped when `EffectiveSlideDuration::slide_secs == 0.0` (Instant speed).
+pub(super) fn start_flip_anim(
+    mut events: MessageReader<CardFlippedEvent>,
+    slide_dur: Option<Res<EffectiveSlideDuration>>,
+    mut commands: Commands,
+    card_entities: Query<(Entity, &CardEntity)>,
+) {
+    if slide_dur.is_some_and(|d| d.slide_secs == 0.0) {
+        // Instant animation speed — skip the flip effect entirely.
+        events.clear();
+        return;
+    }
+
+    for CardFlippedEvent(flipped_card) in events.read() {
+        for (entity, marker) in &card_entities {
+            if marker.card == *flipped_card {
+                commands.entity(entity).insert(CardFlipAnim {
+                    timer: 0.0,
+                    phase: FlipPhase::ScalingDown,
+                });
+                break;
+            }
+        }
+    }
+}
+
+/// Advances `CardFlipAnim` each frame, modifying `Transform::scale.x`.
+///
+/// - Phase `ScalingDown`: lerps scale.x from 1.0 → 0.0 over `FLIP_HALF_SECS`.
+/// - At the midpoint the phase switches to `ScalingUp`, scale.x resets to 0,
+///   and a `CardFaceRevealedEvent` is fired so audio plays in sync with the reveal.
+/// - Phase `ScalingUp`:  lerps scale.x from 0.0 → 1.0 over `FLIP_HALF_SECS`.
+/// - When complete the component is removed and scale.x is restored to 1.0.
+pub(super) fn tick_flip_anim(
+    mut commands: Commands,
+    time: Res<Time>,
+    mut anims: Query<(Entity, &CardEntity, &mut Transform, &mut CardFlipAnim)>,
+    mut reveal_events: MessageWriter<CardFaceRevealedEvent>,
+) {
+    let dt = time.delta_secs();
+    for (entity, card_entity, mut transform, mut anim) in &mut anims {
+        anim.timer += dt;
+        match anim.phase {
+            FlipPhase::ScalingDown => {
+                let t = (anim.timer / FLIP_HALF_SECS).min(1.0);
+                transform.scale.x = 1.0 - t;
+                if t >= 1.0 {
+                    anim.phase = FlipPhase::ScalingUp;
+                    anim.timer = 0.0;
+                    transform.scale.x = 0.0;
+                    // Fire the reveal event exactly once, at the phase transition,
+                    // so the flip sound is synchronised with the visual face reveal.
+                    reveal_events.write(CardFaceRevealedEvent(card_entity.card.clone()));
+                }
+            }
+            FlipPhase::ScalingUp => {
+                let t = (anim.timer / FLIP_HALF_SECS).min(1.0);
+                transform.scale.x = t;
+                if t >= 1.0 {
+                    transform.scale.x = 1.0;
+                    commands.entity(entity).remove::<CardFlipAnim>();
+                }
+            }
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Task #38 — Drag-elevation shadow
+// ---------------------------------------------------------------------------
+
+/// Maintains a single `ShadowEntity` while cards are being dragged.
+///
+/// - If a drag is active, spawns (or repositions) a semi-transparent dark
+///   sprite behind the top dragged card.
+/// - If no drag is active, despawns the shadow entity.
+pub(super) fn update_drag_shadow(
+    mut commands: Commands,
+    drag: Res<DragState>,
+    layout: Option<Res<LayoutResource>>,
+    card_entities: Query<(&CardEntity, &Transform)>,
+    card_index: Res<CardEntityIndex>,
+    mut shadow: Local<Option<Entity>>,
+) {
+    if drag.is_idle() {
+        // No drag in progress — remove shadow if it exists.
+        if let Some(e) = shadow.take() {
+            commands.entity(e).despawn();
+        }
+        return;
+    }
+
+    let Some(layout) = layout else { return };
+    let card_w = layout.0.card_size.x;
+    let card_h = layout.0.card_size.y;
+
+    // Find the world position of the first (top) dragged card.
+    let top_pos = drag.cards.first().and_then(|first_card| {
+        card_index
+            .get(first_card)
+            .and_then(|entity| card_entities.get(entity).ok())
+            .map(|(_, t)| t.translation)
+    });
+
+    let Some(top_pos) = top_pos else { return };
+
+    // Shadow is slightly larger, offset behind-and-below, at a z slightly
+    // below the dragged cards.
+    let shadow_pos = top_pos + Vec3::new(-4.0, 4.0, -1.0);
+
+    match *shadow {
+        Some(e) => {
+            // Reposition the existing shadow.
+            commands
+                .entity(e)
+                .insert(Transform::from_translation(shadow_pos));
+        }
+        None => {
+            // Spawn a new shadow sprite. Alpha tracks the per-card
+            // CARD_SHADOW_ALPHA_DRAG token so the Terminal palette's
+            // "no box-shadow" policy disables this stack shadow in
+            // lockstep with the per-card shadows. Re-enabling shadows
+            // is then a one-line change in `ui_theme`, not a hunt
+            // through plugin code.
+            let e = commands
+                .spawn((
+                    ShadowEntity,
+                    Sprite {
+                        color: CARD_SHADOW_COLOR.with_alpha(CARD_SHADOW_ALPHA_DRAG),
+                        custom_size: Some(Vec2::new(card_w + 8.0, card_h + 8.0)),
+                        ..default()
+                    },
+                    Transform::from_translation(shadow_pos),
+                    Visibility::default(),
+                ))
+                .id();
+            *shadow = Some(e);
+        }
+    }
+}
+
+/// Snaps every per-card [`CardShadow`] between its idle and lifted tunings
+/// based on whether the parent [`CardEntity`] is currently in
+/// [`DragState::cards`]. Runs every frame; the transition is an instant snap
+/// (no lerp) — the existing shake / settle feedback already handles motion
+/// at drag-end, so an additional shadow tween would compete with those cues.
+///
+/// The shadow size is rebuilt from the parent card's current `Sprite`
+/// `custom_size` plus the appropriate padding, so the resize handler does
+/// not need to pre-tune shadow sizes for the drag state — this system fixes
+/// the geometry within one frame.
+pub(super) fn update_card_shadows_on_drag(
+    drag: Res<DragState>,
+    cards: Query<(&CardEntity, &Sprite, &Children), Without<CardShadow>>,
+    mut shadows: Query<(&mut Sprite, &mut Transform), With<CardShadow>>,
+) {
+    let dragged: HashSet<&Card> = drag.cards.iter().collect();
+
+    for (card_entity, card_sprite, children) in cards.iter() {
+        let is_dragged = dragged.contains(&card_entity.card);
+        let (offset, padding, alpha) = card_shadow_params(is_dragged);
+        let Some(card_size) = card_sprite.custom_size else {
+            continue;
+        };
+
+        for child in children.iter() {
+            let Ok((mut shadow_sprite, mut shadow_transform)) = shadows.get_mut(child) else {
+                continue;
+            };
+            shadow_sprite.color = CARD_SHADOW_COLOR.with_alpha(alpha);
+            shadow_sprite.custom_size = Some(card_size + padding);
+            shadow_transform.translation.x = offset.x;
+            shadow_transform.translation.y = offset.y;
+            shadow_transform.translation.z = CARD_SHADOW_LOCAL_Z;
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Task #28 — Hint highlight tick system
+// ---------------------------------------------------------------------------
+

solitaire_engine/src/card_plugin/highlights.rs

@@ -0,0 +1,276 @@
+//! Hint and right-click highlights, plus cursor hit-testing helpers.
+
+use super::*;
+
+
+use bevy::color::Color;
+use solitaire_core::Card;
+use solitaire_core::game_state::GameState;
+
+use crate::events::StateChangedEvent;
+use crate::layout::{Layout, LayoutResource};
+use crate::pause_plugin::PausedResource;
+use crate::resources::{DragState, GameStateResource};
+use crate::settings_plugin::SettingsResource;
+use crate::table_plugin::{PILE_MARKER_DEFAULT_COLOUR, PileMarker};
+
+/// Counts down `HintHighlight::remaining` each frame. When it reaches zero,
+/// removes both `HintHighlight` and `HintHighlightTimer` (if present) and
+/// resets the card sprite to its normal face-up colour.
+pub(super) fn tick_hint_highlight(
+    time: Res<Time>,
+    mut commands: Commands,
+    mut query: Query<(Entity, &mut HintHighlight, &mut Sprite, &CardEntity)>,
+    game: Res<GameStateResource>,
+    settings: Option<Res<SettingsResource>>,
+    card_images: Option<Res<CardImageSet>>,
+) {
+    let back_idx = settings.as_ref().map_or(0, |s| s.0.selected_card_back);
+    let use_images = card_images.is_some();
+    for (entity, mut hint, mut sprite, card_entity) in query.iter_mut() {
+        hint.remaining -= time.delta_secs();
+        if hint.remaining <= 0.0 {
+            // Restore the normal sprite colour.
+            // When image-based rendering is active, WHITE is the neutral tint;
+            // otherwise restore the solid colour appropriate to the card state.
+            sprite.color = if use_images {
+                Color::WHITE
+            } else {
+                let is_face_up = all_cards(&game.0)
+                    .iter()
+                    .find(|(c, _face_up)| *c == card_entity.card)
+                    .is_some_and(|(_, face_up)| *face_up);
+                if is_face_up {
+                    CARD_FACE_COLOUR
+                } else {
+                    card_back_colour(back_idx)
+                }
+            };
+            commands
+                .entity(entity)
+                .remove::<HintHighlight>()
+                .remove::<HintHighlightTimer>();
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Task #46 — Right-click legal destination highlights
+// ---------------------------------------------------------------------------
+
+/// Lime tint applied to a `PileMarker` sprite when it is a legal
+/// destination for the right-clicked card. Same RGB as the design-
+/// system [`STATE_SUCCESS`] token at 60% alpha. Spelled as a literal
+/// because `Alpha::with_alpha` is not yet a `const` trait method on
+/// stable; the tracking test below pins the RGB to `STATE_SUCCESS`
+/// so a palette swap can't drift the two apart silently.
+pub(super) const RIGHT_CLICK_HIGHLIGHT_COLOUR: Color = Color::srgba(0.675, 0.761, 0.404, 0.6);
+
+/// Counts down `RightClickHighlightTimer` each frame and clears the highlight
+/// when the timer expires.
+///
+/// This is a fallback expiry: highlights also clear immediately on
+/// `StateChangedEvent` (move made) or when the game is paused, whichever comes
+/// first. The 1.5 s timer ensures highlights always disappear even if the
+/// player takes no further action.
+pub(super) fn tick_right_click_highlights(
+    mut commands: Commands,
+    time: Res<Time>,
+    paused: Option<Res<PausedResource>>,
+    mut highlights: Query<
+        (Entity, &mut RightClickHighlightTimer, &mut Sprite),
+        With<RightClickHighlight>,
+    >,
+) {
+    if paused.is_some_and(|p| p.0) {
+        return;
+    }
+    let dt = time.delta_secs();
+    for (entity, mut timer, mut sprite) in &mut highlights {
+        timer.0 -= dt;
+        if timer.0 <= 0.0 {
+            // Restore the pile marker to its default colour before removing
+            // the highlight marker component.
+            sprite.color = PILE_MARKER_DEFAULT_COLOUR;
+            commands
+                .entity(entity)
+                .remove::<RightClickHighlight>()
+                .remove::<RightClickHighlightTimer>();
+        }
+    }
+}
+
+/// Removes the `RightClickHighlight` marker from every highlighted pile and
+/// resets its sprite colour to `PILE_MARKER_DEFAULT_COLOUR`.
+///
+/// Shared by the on-state-change and on-pause clear systems to avoid
+/// duplicating the removal logic.
+pub(super) fn clear_right_click_highlights(
+    commands: &mut Commands,
+    highlighted: &Query<Entity, With<RightClickHighlight>>,
+    pile_markers: &mut Query<(Entity, &PileMarker, &mut Sprite)>,
+) {
+    for entity in highlighted.iter() {
+        commands.entity(entity).remove::<RightClickHighlight>();
+    }
+    for (_entity, _, mut sprite) in pile_markers.iter_mut() {
+        if sprite.color == RIGHT_CLICK_HIGHLIGHT_COLOUR {
+            sprite.color = PILE_MARKER_DEFAULT_COLOUR;
+        }
+    }
+}
+
+/// Clears all right-click destination highlights whenever any game-state
+/// mutation succeeds (`StateChangedEvent` fires).
+///
+/// This ensures stale highlights do not linger after a card is moved.
+pub(super) fn clear_right_click_highlights_on_state_change(
+    mut events: MessageReader<StateChangedEvent>,
+    mut commands: Commands,
+    highlighted: Query<Entity, With<RightClickHighlight>>,
+    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite)>,
+) {
+    if events.read().next().is_none() {
+        return;
+    }
+    clear_right_click_highlights(&mut commands, &highlighted, &mut pile_markers);
+}
+
+/// Clears all right-click destination highlights when the game is paused
+/// (`PausedResource` changes to `true`).
+///
+/// Prevents highlighted pile markers from remaining visible behind the pause
+/// overlay.
+pub(super) fn clear_right_click_highlights_on_pause(
+    paused: Option<Res<PausedResource>>,
+    mut commands: Commands,
+    highlighted: Query<Entity, With<RightClickHighlight>>,
+    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite)>,
+) {
+    let Some(paused) = paused else { return };
+    if paused.is_changed() && paused.0 {
+        clear_right_click_highlights(&mut commands, &highlighted, &mut pile_markers);
+    }
+}
+
+/// Handles right-click: highlights legal destination piles for the clicked card,
+/// and clears highlights on any subsequent right- or left-click.
+///
+/// This system lives in `CardPlugin` to keep `InputPlugin` untouched.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn handle_right_click(
+    buttons: Option<Res<ButtonInput<MouseButton>>>,
+    paused: Option<Res<PausedResource>>,
+    drag: Res<DragState>,
+    windows: Query<&Window, With<bevy::window::PrimaryWindow>>,
+    cameras: Query<(&Camera, &GlobalTransform)>,
+    layout: Option<Res<LayoutResource>>,
+    game: Res<GameStateResource>,
+    mut commands: Commands,
+    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite)>,
+    card_entities: Query<(Entity, &CardEntity, &Transform)>,
+    highlighted: Query<Entity, With<RightClickHighlight>>,
+) {
+    if paused.is_some_and(|p| p.0) {
+        return;
+    }
+
+    let Some(buttons) = buttons else { return };
+    let left_pressed = buttons.just_pressed(MouseButton::Left);
+    let right_pressed = buttons.just_pressed(MouseButton::Right);
+
+    // Clear existing highlights on any click.
+    if left_pressed || right_pressed {
+        for entity in &highlighted {
+            commands.entity(entity).remove::<RightClickHighlight>();
+        }
+        for (_entity, _, mut sprite) in &mut pile_markers {
+            if sprite.color == RIGHT_CLICK_HIGHLIGHT_COLOUR {
+                sprite.color = PILE_MARKER_DEFAULT_COLOUR;
+            }
+        }
+    }
+
+    // Only proceed for right-clicks while not dragging.
+    if !right_pressed || !drag.is_idle() {
+        return;
+    }
+
+    let Some(layout) = layout else { return };
+
+    // Convert cursor to world-space position.
+    let Some(world) = cursor_world_pos(&windows, &cameras) else {
+        return;
+    };
+
+    // Find the topmost face-up card under the cursor.
+    let Some(card) = find_top_card_at(world, &game.0, &layout.0, &card_entities) else {
+        return;
+    };
+
+    let Some(source_pile) = game.0.pile_containing_card(card.clone()) else {
+        return;
+    };
+
+    // Tint piles that legally accept the card.
+    for (entity, pile_marker, mut sprite) in &mut pile_markers {
+        let legal = game.0.can_move_cards(&source_pile, &pile_marker.0, 1);
+        if legal {
+            sprite.color = RIGHT_CLICK_HIGHLIGHT_COLOUR;
+            commands
+                .entity(entity)
+                .insert(RightClickHighlight)
+                .insert(RightClickHighlightTimer(1.5));
+        }
+    }
+}
+
+/// Converts cursor position to 2-D world coordinates.
+pub(super) fn cursor_world_pos(
+    windows: &Query<&Window, With<bevy::window::PrimaryWindow>>,
+    cameras: &Query<(&Camera, &GlobalTransform)>,
+) -> Option<Vec2> {
+    let window = windows.single().ok()?;
+    let cursor = window.cursor_position()?;
+    let (camera, camera_transform) = cameras.single().ok()?;
+    camera.viewport_to_world_2d(camera_transform, cursor).ok()
+}
+
+/// Returns the topmost face-up `Card` under `cursor` by checking axis-aligned
+/// bounding rectangles of all card sprites, picking the highest Z.
+pub(super) fn find_top_card_at(
+    cursor: Vec2,
+    game: &GameState,
+    layout: &Layout,
+    card_entities: &Query<(Entity, &CardEntity, &Transform)>,
+) -> Option<Card> {
+    let half = layout.card_size / 2.0;
+    let mut best: Option<(f32, Card)> = None;
+
+    for (_, card_entity, transform) in card_entities.iter() {
+        let pos = transform.translation.truncate();
+        if cursor.x < pos.x - half.x
+            || cursor.x > pos.x + half.x
+            || cursor.y < pos.y - half.y
+            || cursor.y > pos.y + half.y
+        {
+            continue;
+        }
+        let found = all_cards(game)
+            .into_iter()
+            .find(|(c, face_up)| *c == card_entity.card && *face_up);
+        if let Some((card, _)) = found {
+            let z = transform.translation.z;
+            if best.as_ref().is_none_or(|(bz, _)| z > *bz) {
+                best = Some((z, card));
+            }
+        }
+    }
+    best.map(|(_, card)| card)
+}
+
+// ---------------------------------------------------------------------------
+// Task #28 — Stock-empty visual indicator
+// ---------------------------------------------------------------------------
+
+

solitaire_engine/src/card_plugin/labels.rs

@@ -0,0 +1,208 @@
+//! Card face labels: desktop text labels and Android corner labels.
+
+use super::*;
+
+
+use bevy::color::Color;
+use bevy::sprite::Anchor;
+use solitaire_core::{Card, Rank, Suit};
+
+use crate::ui_theme::TEXT_PRIMARY_HC;
+
+pub(super) fn label_for(card: &Card) -> String {
+    let rank = match card.rank() {
+        Rank::Ace => "A",
+        Rank::Two => "2",
+        Rank::Three => "3",
+        Rank::Four => "4",
+        Rank::Five => "5",
+        Rank::Six => "6",
+        Rank::Seven => "7",
+        Rank::Eight => "8",
+        Rank::Nine => "9",
+        Rank::Ten => "10",
+        Rank::Jack => "J",
+        Rank::Queen => "Q",
+        Rank::King => "K",
+    };
+    let suit = match card.suit() {
+        Suit::Clubs => "C",
+        Suit::Diamonds => "D",
+        Suit::Hearts => "H",
+        Suit::Spades => "S",
+    };
+    format!("{rank}{suit}")
+}
+
+/// Suit colour for the rank/suit overlay rendered atop the constant
+/// fallback sprite (only fires under `MinimalPlugins` — production
+/// renders the suit glyph baked into the PNG). 2-colour traditional
+/// pairing — hearts + diamonds share the saturated red, clubs +
+/// spades share the near-white. Two accessibility flags compose:
+///
+/// - `color_blind`: red-suit cards swap to `RED_SUIT_COLOUR_CBM`
+///   (lime) — the "Settings toggle swaps red→lime" half of the
+///   design system's colour-blind support. CBM is a hue-replacement
+///   for red, so HC has no further effect on red when CBM is on
+///   (the lime is itself a high-luminance colour).
+/// - `high_contrast`: when CBM is off, red suits boost to
+///   `RED_SUIT_COLOUR_HC` (`#ff6868`); black suits boost from
+///   `#e8e8e8` (near-white) to `#f5f5f5` (`TEXT_PRIMARY_HC`).
+///
+/// The other half of CBM support (always-on filled-vs-outlined
+/// glyph differentiation for ♥♠ vs ♦♣) is baked into the PNG art
+/// and has no constant-fallback equivalent.
+pub(super) fn text_colour(card: &Card, color_blind: bool, high_contrast: bool) -> Color {
+    if card.suit().is_red() {
+        if color_blind {
+            // CBM lime wins — the colour-blind swap replaces the
+            // red hue entirely, and the lime is already high-
+            // luminance, so an HC boost on top has nothing to do.
+            RED_SUIT_COLOUR_CBM
+        } else if high_contrast {
+            RED_SUIT_COLOUR_HC
+        } else {
+            RED_SUIT_COLOUR
+        }
+    } else if high_contrast {
+        TEXT_PRIMARY_HC
+    } else {
+        BLACK_SUIT_COLOUR
+    }
+}
+
+pub(super) fn label_visibility(face_up: bool) -> Visibility {
+    if face_up {
+        Visibility::Inherited
+    } else {
+        Visibility::Hidden
+    }
+}
+
+/// Rank+suit string for the readability overlay on touch HUD layouts.
+/// Uses Unicode suit glyphs (♠♥♦♣ — U+2660–U+2666, covered by FiraMono).
+pub(super) fn mobile_label_for(card: &Card) -> String {
+    let rank = match card.rank() {
+        Rank::Ace => "A",
+        Rank::Two => "2",
+        Rank::Three => "3",
+        Rank::Four => "4",
+        Rank::Five => "5",
+        Rank::Six => "6",
+        Rank::Seven => "7",
+        Rank::Eight => "8",
+        Rank::Nine => "9",
+        Rank::Ten => "10",
+        Rank::Jack => "J",
+        Rank::Queen => "Q",
+        Rank::King => "K",
+    };
+    let suit = match card.suit() {
+        Suit::Clubs => "♣",
+        Suit::Diamonds => "♦",
+        Suit::Hearts => "♥",
+        Suit::Spades => "♠",
+    };
+    format!("{rank}{suit}")
+}
+
+/// Spawns the [`AndroidCornerLabel`] + [`AndroidCornerBg`] children on
+/// face-up cards. The background sprite covers the card art's own small
+/// corner text so only the large overlay is visible.
+/// Spawns the [`AndroidCornerLabel`] + [`AndroidCornerBg`] children on
+/// face-up cards using FiraMono (passed via `font_handle`) so that the
+/// suit Unicode glyphs U+2660–U+2666 render correctly. Without an explicit
+/// font handle Bevy falls back to its built-in face which does not include
+/// those glyphs, causing a coloured missing-glyph rectangle to appear in
+/// the text colour — the root cause of the "red square on face-down cards"
+/// visual bug (the box bleeds through near the card edge at z=0.02).
+pub(super) fn add_android_corner_label(
+    parent: &mut ChildSpawnerCommands,
+    card: &Card,
+    face_up: bool,
+    card_size: Vec2,
+    color_blind: bool,
+    high_contrast: bool,
+    font_handle: Option<&Handle<Font>>,
+) {
+    if !face_up {
+        return;
+    }
+    let font_size = card_size.x * FONT_SIZE_FRAC_MOBILE;
+    let inset = 3.0_f32;
+    // Background covers ~3 monospace chars wide × 1 line tall.
+    // FiraMono char width ≈ 0.6 × font_size; 2.0× gives room for "10♠"
+    // (3 chars = 1.8× font_size) plus a small margin.
+    let bg_w = font_size * 2.0;
+    let bg_h = font_size * 1.25;
+
+    // Background covers the PNG's baked-in small corner text (top-left).
+    // Classic PNG cards have a white face, so the background must be white too.
+    // (CARD_FACE_COLOUR is the Terminal theme's dark face colour — wrong here.)
+    parent.spawn((
+        AndroidCornerBg,
+        Sprite {
+            color: Color::WHITE,
+            custom_size: Some(Vec2::new(bg_w, bg_h)),
+            ..default()
+        },
+        Transform::from_xyz(
+            -card_size.x / 2.0 + inset + bg_w / 2.0,
+            card_size.y / 2.0 - inset - bg_h / 2.0,
+            0.015,
+        ),
+    ));
+    // Cover the matching rotated baked-in text at the bottom-right corner.
+    parent.spawn((
+        AndroidCornerBg,
+        Sprite {
+            color: Color::WHITE,
+            custom_size: Some(Vec2::new(bg_w, bg_h)),
+            ..default()
+        },
+        Transform::from_xyz(
+            card_size.x / 2.0 - inset - bg_w / 2.0,
+            -card_size.y / 2.0 + inset + bg_h / 2.0,
+            0.015,
+        ),
+    ));
+
+    // Large rank+suit text drawn on top of the background. FiraMono must be
+    // wired here explicitly — the suit glyphs (U+2660–U+2666) are not in
+    // Bevy's built-in font and render as a coloured rectangle without it.
+    //
+    // Classic PNG cards have a white face: red suits stay the same saturated
+    // red, but black suits must use a dark colour (CARD_FACE_COLOUR ≈ #1a1a1a)
+    // rather than the near-white BLACK_SUIT_COLOUR designed for the dark
+    // Terminal theme background.
+    let text_col = if card.suit().is_red() {
+        if color_blind {
+            RED_SUIT_COLOUR_CBM
+        } else if high_contrast {
+            RED_SUIT_COLOUR_HC
+        } else {
+            RED_SUIT_COLOUR
+        }
+    } else {
+        CARD_FACE_COLOUR
+    };
+    let label_text = mobile_label_for(card);
+    parent.spawn((
+        AndroidCornerLabel(label_text.clone()),
+        CardLabel,
+        Text2d::new(label_text),
+        TextFont {
+            font: font_handle.cloned().unwrap_or_default(),
+            font_size,
+            ..default()
+        },
+        TextColor(text_col),
+        Anchor::TOP_LEFT,
+        Transform::from_xyz(-card_size.x / 2.0 + inset, card_size.y / 2.0 - inset, 0.02),
+    ));
+}
+
+// ---------------------------------------------------------------------------
+// Task #34 — Card-flip animation systems
+// ---------------------------------------------------------------------------
+

solitaire_engine/src/card_plugin/layout.rs

@@ -0,0 +1,351 @@
+//! Resize handling: window-resize snapping, in-place card resizing,
+//! and tableau fan spread.
+
+use super::*;
+
+use std::collections::HashMap;
+
+use bevy::window::WindowResized;
+use solitaire_core::Card;
+use solitaire_core::game_state::GameState;
+
+use crate::animation_plugin::CardAnim;
+use crate::events::StateChangedEvent;
+use crate::font_plugin::FontResource;
+use crate::layout::{Layout, LayoutResource};
+use crate::resources::GameStateResource;
+use crate::table_plugin::PileMarker;
+use crate::ui_theme::{
+    CARD_SHADOW_ALPHA_DRAG, CARD_SHADOW_PADDING_DRAG,
+    CARD_SHADOW_PADDING_IDLE,
+};
+
+/// Coalesces every `WindowResized` event arriving this frame into the latest
+/// pending size on [`ResizeThrottle`].
+///
+/// `WindowResized` fires per pixel of resize drag, so a fast corner drag can
+/// emit many events per frame. Reading `.last()` keeps only the final size —
+/// every frame's snap target is the most recent window size, never a stale
+/// one. Pending stays set across frames until the throttled applier consumes
+/// it; that's how we still flush the final "release" position when the user
+/// stops dragging.
+pub(super) fn collect_resize_events(
+    mut events: MessageReader<WindowResized>,
+    mut throttle: ResMut<ResizeThrottle>,
+) {
+    if let Some(ev) = events.read().last() {
+        throttle.pending = Some(Vec2::new(ev.width, ev.height));
+    }
+}
+
+/// Snaps every card sprite to its target position, size, and (in the
+/// fallback Text2d label path) font size when the window is resized.
+///
+/// **In-place mutation only.** Resize is the hot path — events fire per
+/// pixel of drag, so this system cannot afford the despawn/respawn churn
+/// `update_card_entity` does. We mutate `Sprite.custom_size`, `Transform`,
+/// and child `TextFont.font_size` directly, leaving the card image handle,
+/// suit/rank, and `CardLabel` entity untouched. Cards keep their identity
+/// across resizes; only their size and position change. The full repaint
+/// path lives in [`update_card_entity`] and is still used by every non-resize
+/// caller (deals, moves, flips, settings toggles).
+///
+/// **Throttled to ~20 Hz.** [`ResizeThrottle::pending`] is consumed at most
+/// once per [`RESIZE_THROTTLE_SECS`]. When events stop arriving, the next
+/// tick past the throttle window flushes the final size and clears
+/// `pending`, so the steady-state always matches the user's release size.
+///
+/// **Cancels in-flight slides.** Any `CardAnim` is removed so a mid-slide
+/// tween is not retargeted relative to the previous card-size's position.
+///
+/// The "↺" stock-empty label's `font_size` is derived from
+/// `layout.card_size.x`, so this system also reapplies the stock indicator —
+/// otherwise the label would not rescale on resize.
+///
+/// Scheduled after [`collect_resize_events`] (which itself runs after
+/// `LayoutSystem::UpdateOnResize`) so `LayoutResource` reflects the latest
+/// window size before we read it.
+#[allow(clippy::too_many_arguments, clippy::type_complexity)]
+pub(super) fn snap_cards_on_window_resize(
+    mut commands: Commands,
+    time: Res<Time>,
+    mut throttle: ResMut<ResizeThrottle>,
+    game: Option<Res<GameStateResource>>,
+    layout: Option<Res<LayoutResource>>,
+    card_images: Option<Res<CardImageSet>>,
+    font_res: Option<Res<FontResource>>,
+    entities: Query<
+        (Entity, &CardEntity, &mut Sprite, &mut Transform),
+        (
+            Without<CardLabel>,
+            Without<CardShadow>,
+            Without<CardBackFrame>,
+        ),
+    >,
+    label_query: Query<&mut TextFont, (With<CardLabel>, Without<StockEmptyLabel>)>,
+    shadow_query: Query<
+        &mut Sprite,
+        (
+            With<CardShadow>,
+            Without<CardEntity>,
+            Without<PileMarker>,
+            Without<CardBackFrame>,
+        ),
+    >,
+    frame_query: Query<
+        &mut Sprite,
+        (
+            With<CardBackFrame>,
+            Without<CardEntity>,
+            Without<CardShadow>,
+            Without<PileMarker>,
+        ),
+    >,
+    mut pile_markers: Query<
+        (Entity, &PileMarker, &mut Sprite),
+        (
+            Without<CardEntity>,
+            Without<CardShadow>,
+            Without<CardBackFrame>,
+        ),
+    >,
+    label_children: Query<(Entity, &ChildOf), With<StockEmptyLabel>>,
+) {
+    if throttle.pending.is_none() {
+        return;
+    }
+    let now = time.elapsed_secs();
+    if !should_apply_resize(now, throttle.last_applied_secs) {
+        return;
+    }
+
+    let Some(game) = game else {
+        // Nothing to apply — clear pending so we don't busy-loop.
+        throttle.pending = None;
+        return;
+    };
+    let Some(layout) = layout else {
+        throttle.pending = None;
+        return;
+    };
+
+    resize_cards_in_place(
+        &mut commands,
+        &game.0,
+        &layout.0,
+        card_images.as_deref(),
+        entities,
+        label_query,
+        shadow_query,
+        frame_query,
+    );
+
+    let font = font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default();
+    apply_stock_empty_indicator(
+        &mut commands,
+        &game.0,
+        &mut pile_markers,
+        &label_children,
+        &layout.0,
+        font,
+    );
+
+    throttle.last_applied_secs = now;
+    throttle.pending = None;
+}
+
+/// In-place "size-only" sibling of [`sync_cards`]: walks every existing card
+/// entity, updates `Sprite.custom_size` and the snap-`Transform` to match the
+/// fresh layout, and (in fallback solid-colour mode) also updates the child
+/// `TextFont.font_size` of any `CardLabel`. No despawning, no `Sprite`
+/// replacement, no children rebuild — that's the entire point of this path.
+///
+/// Called only from the resize handler. Game-state changes (deals, moves,
+/// flips, settings toggles) still flow through [`sync_cards`] /
+/// [`update_card_entity`], which handle add/remove/repaint correctly.
+///
+/// Any in-flight `CardAnim` slide is removed so a mid-tween card is not
+/// retargeted relative to the previous card-size's position.
+#[allow(clippy::type_complexity, clippy::too_many_arguments)]
+pub(super) fn resize_cards_in_place(
+    commands: &mut Commands,
+    game: &GameState,
+    layout: &Layout,
+    card_images: Option<&CardImageSet>,
+    mut entities: Query<
+        (Entity, &CardEntity, &mut Sprite, &mut Transform),
+        (
+            Without<CardLabel>,
+            Without<CardShadow>,
+            Without<CardBackFrame>,
+        ),
+    >,
+    mut label_query: Query<&mut TextFont, (With<CardLabel>, Without<StockEmptyLabel>)>,
+    mut shadow_query: Query<
+        &mut Sprite,
+        (
+            With<CardShadow>,
+            Without<CardEntity>,
+            Without<PileMarker>,
+            Without<CardBackFrame>,
+        ),
+    >,
+    mut frame_query: Query<
+        &mut Sprite,
+        (
+            With<CardBackFrame>,
+            Without<CardEntity>,
+            Without<CardShadow>,
+            Without<PileMarker>,
+        ),
+    >,
+) {
+    let positions = card_positions(game, layout);
+    let pos_by_id: HashMap<Card, (Vec2, f32)> = positions
+        .into_iter()
+        .map(|((c, _face_up), p, z)| (c, (p, z)))
+        .collect();
+
+    for (entity, marker, mut sprite, mut transform) in entities.iter_mut() {
+        let Some(&(pos, z)) = pos_by_id.get(&marker.card) else {
+            continue;
+        };
+        sprite.custom_size = Some(layout.card_size);
+        transform.translation.x = pos.x;
+        transform.translation.y = pos.y;
+        transform.translation.z = z;
+        // Cancel any in-flight slide so it doesn't retarget from a stale
+        // mid-animation position computed against the previous card size.
+        commands.entity(entity).remove::<CardAnim>();
+    }
+
+    // Resize every per-card shadow halo to match the new card size. Both
+    // idle and drag states scale with the card body, so we preserve the
+    // *current* padding (idle vs drag) by keeping the alpha as-is and only
+    // recomputing the geometry. The drag-tracking system runs every frame
+    // and will retune offset / alpha / padding-mode within one frame if the
+    // drag state diverges from the resized geometry.
+    let idle_padding = CARD_SHADOW_PADDING_IDLE;
+    let drag_padding = CARD_SHADOW_PADDING_DRAG;
+    for mut shadow_sprite in shadow_query.iter_mut() {
+        // Choose padding based on the shadow's current alpha — preserves
+        // a lifted shadow's larger halo across resize without needing to
+        // plumb DragState through the resize handler.
+        let alpha = shadow_sprite.color.alpha();
+        let padding = if alpha >= CARD_SHADOW_ALPHA_DRAG - 0.001 {
+            drag_padding
+        } else {
+            idle_padding
+        };
+        shadow_sprite.custom_size = Some(layout.card_size + padding);
+    }
+
+    // Only the solid-colour fallback path uses CardLabel/Text2d overlays;
+    // when PNG faces are loaded the rank/suit are baked into the image and
+    // there is nothing to resize on the label side.
+    if card_images.is_none() {
+        let new_font_size = layout.card_size.x * FONT_SIZE_FRAC;
+        for mut font in label_query.iter_mut() {
+            font.font_size = new_font_size;
+        }
+    }
+
+    // Resize every face-down border frame to match the new card size.
+    let frame_size = layout.card_size + Vec2::splat(CARD_BACK_FRAME_PADDING);
+    for mut frame_sprite in frame_query.iter_mut() {
+        frame_sprite.custom_size = Some(frame_size);
+    }
+}
+
+/// Updates font size and top-left anchor transform of every
+/// [`AndroidCornerLabel`] entity when `LayoutResource` changes (orientation
+/// change or any window resize). The full despawn/respawn path in
+/// `update_card_entity` already handles game-state changes; this system
+/// covers the resize-only path where children are mutated in place.
+pub(super) fn resize_android_corner_labels(
+    layout: Res<LayoutResource>,
+    card_images: Option<Res<CardImageSet>>,
+    mut text_query: Query<(
+        &AndroidCornerLabel,
+        &mut Text2d,
+        &mut TextFont,
+        &mut Transform,
+    )>,
+    mut bg_query: Query<(&mut Sprite, &mut Transform), AndroidCornerBgFilter>,
+) {
+    if !layout.is_changed() || card_images.is_none() {
+        return;
+    }
+    let font_size = layout.0.card_size.x * FONT_SIZE_FRAC_MOBILE;
+    let inset = 3.0_f32;
+    let bg_w = font_size * 2.0;
+    let bg_h = font_size * 1.25;
+    let text_x = -layout.0.card_size.x / 2.0 + inset;
+    let text_y = layout.0.card_size.y / 2.0 - inset;
+
+    for (label, mut text2d, mut font, mut transform) in text_query.iter_mut() {
+        text2d.0 = label.0.clone();
+        font.font_size = font_size;
+        transform.translation.x = text_x;
+        transform.translation.y = text_y;
+    }
+    for (mut sprite, mut transform) in bg_query.iter_mut() {
+        sprite.custom_size = Some(Vec2::new(bg_w, bg_h));
+        transform.translation.x = text_x + bg_w / 2.0;
+        transform.translation.y = text_y - bg_h / 2.0;
+    }
+}
+
+/// Adjusts `LayoutResource.tableau_fan_frac` (and the face-down companion) so
+/// the deepest tableau column fills the available vertical space at every stage
+/// of play. Runs after every `StateChangedEvent`.
+///
+/// Depth is measured across *all* cards in a column, weighting each face-down
+/// card by the fixed face-down/face-up step ratio. Counting the face-down
+/// portion — not just the face-up tail — is what fills the lower screen on a
+/// fresh deal (the deepest column is then six face-down cards under one face-up
+/// one): the earlier face-up-only depth was 1, so the fan never spread and the
+/// bottom half of a near-square viewport (e.g. an unfolded foldable) sat empty.
+///
+/// Deeper columns drive the fraction down so everything still fits the window;
+/// [`crate::layout::TABLEAU_FAN_FRAC`] floors it to the desktop feel and
+/// [`MAX_DYNAMIC_FAN_FRAC`] caps it so a near-empty column doesn't fling its few
+/// cards far apart.
+pub(super) fn update_tableau_fan_frac(
+    mut events: MessageReader<StateChangedEvent>,
+    game: Option<Res<GameStateResource>>,
+    mut layout: Option<ResMut<LayoutResource>>,
+) {
+    if events.read().next().is_none() {
+        return;
+    }
+    let Some(game) = game else {
+        return;
+    };
+    let Some(layout) = layout.as_mut() else {
+        return;
+    };
+    crate::layout::apply_dynamic_tableau_fan(&game.0, &mut layout.0);
+}
+
+/// PostStartup sibling of [`update_tableau_fan_frac`]. The initial deal is
+/// inserted directly as `GameStateResource` at startup without a
+/// `StateChangedEvent`, so the event-driven system never fires for it. This
+/// runs once, before [`sync_cards_startup`] renders, so the very first board
+/// (cold start) already fills the viewport — otherwise a fresh deal on a tall /
+/// near-square screen (e.g. an unfolded foldable) renders with the unspread fan
+/// and a large empty band below the tableau until the first move.
+pub(super) fn fill_tableau_fan_on_startup(
+    game: Option<Res<GameStateResource>>,
+    mut layout: Option<ResMut<LayoutResource>>,
+) {
+    let Some(game) = game else {
+        return;
+    };
+    let Some(layout) = layout.as_mut() else {
+        return;
+    };
+    crate::layout::apply_dynamic_tableau_fan(&game.0, &mut layout.0);
+}
+
+

solitaire_engine/src/card_plugin/mod.rs

@@ -0,0 +1,574 @@
+//! PNG-based card rendering.
+//!
+//! Card entities are synced with [`GameStateResource`] on every
+//! [`StateChangedEvent`]: missing cards are spawned, present cards are
+//! repositioned/updated in place, and stale cards are despawned.
+//!
+//! When [`CardImageSet`] is available, each face-up card renders its own
+//! 120×168 px `Handle<Image>` chosen from the 52 per-card PNGs loaded from
+//! `assets/cards/faces/{rank}_{suit}.png`. A solid-colour `Sprite` with a
+//! `Text2d` rank+suit overlay is used as a fallback when `CardImageSet` is
+//! absent (e.g. in tests running under `MinimalPlugins`).
+
+use std::collections::HashMap;
+
+use bevy::color::Color;
+use bevy::prelude::*;
+use solitaire_core::{KlondikePile, Tableau};
+use solitaire_core::Card;
+
+use crate::card_animation::CardAnimation;
+use crate::events::{CardFaceRevealedEvent, CardFlippedEvent};
+use crate::game_plugin::GameMutation;
+use crate::layout::{Layout, LayoutSystem};
+
+mod anim;
+mod highlights;
+mod labels;
+mod layout;
+mod stock;
+mod sync;
+
+use anim::*;
+use highlights::*;
+use labels::*;
+use layout::*;
+use stock::*;
+use sync::*;
+
+use crate::resources::GameStateResource;
+use crate::settings_plugin::SettingsChangedEvent;
+use crate::ui_theme::{
+    CARD_SHADOW_ALPHA_DRAG, CARD_SHADOW_ALPHA_IDLE, CARD_SHADOW_COLOR, CARD_SHADOW_LOCAL_Z,
+    CARD_SHADOW_OFFSET_DRAG, CARD_SHADOW_OFFSET_IDLE, CARD_SHADOW_PADDING_DRAG,
+    CARD_SHADOW_PADDING_IDLE,
+};
+
+/// Per-card vertical step for face-down tableau cards, as a fraction of
+/// card height. Smaller than [`crate::layout::TABLEAU_FAN_FRAC`] because face-down cards
+/// don't need their full body shown — only the back-pattern strip is
+/// visible. Public so `input_plugin` can mirror the exact sprite layout
+/// when hit-testing tableau columns; any drift between this and the
+/// renderer creates a visible offset between the card face and where
+/// clicks land.
+///
+/// Matches `layout::TABLEAU_FACEDOWN_FAN_FRAC` (0.14). Both constants must
+/// stay in sync; the layout constant drives the adaptive LayoutResource value
+/// used at runtime, while this one is the minimum floor used by
+/// `update_tableau_fan_frac` when computing proportional updates.
+pub const TABLEAU_FACEDOWN_FAN_FRAC: f32 = 0.14;
+
+/// Fraction of card height used as a tiny offset between stacked cards in
+/// non-tableau piles, so stacking is visible. Public so other plugins
+/// (e.g. input_plugin's drag-rejection tween) can compute the resting
+/// `Transform.translation.z` for a card at a given stack index without
+/// drifting from the value used by [`card_positions`].
+// Must exceed the highest child local-z of any card entity (0.02 for the
+// Android corner label) so every card's sprite covers all children of the
+// card below it.  Raising from 0.003 → 0.025 fixes corner labels on
+// foundation piles bleeding through when a 2 sits on an Ace.
+pub const STACK_FAN_FRAC: f32 = 0.025;
+
+/// Per-card horizontal fan step for the Draw-Three waste, in logical pixels.
+///
+/// Derived from the actual tableau column spacing (`Tableau2.x − Tableau1.x`)
+/// rather than a fixed fraction of card width, so the fan scales with the
+/// platform's `H_GAP_DIVISOR` (desktop ≈ 1.25×cw spacing, Android ≈ 1.03×cw).
+/// Public so `input_plugin` can hit-test the fanned waste cards at the exact
+/// x-offsets the renderer uses; any drift makes a click on the top fanned card
+/// land on the card beneath it.
+pub fn waste_fan_step(layout: &Layout) -> f32 {
+    tableau_col_step(layout) * 0.224
+}
+
+/// Horizontal distance between adjacent tableau columns (`Tableau2.x −
+/// Tableau1.x`), in logical pixels. The face-down stock is rendered one column
+/// step left of the waste, and the Draw-Three waste fan ([`waste_fan_step`]) is
+/// a fraction of it. Public so hit-testing mirrors the renderer exactly.
+pub fn tableau_col_step(layout: &Layout) -> f32 {
+    let t1 = layout
+        .pile_positions
+        .get(&KlondikePile::Tableau(Tableau::Tableau1))
+        .copied()
+        .unwrap_or_default();
+    let t2 = layout
+        .pile_positions
+        .get(&KlondikePile::Tableau(Tableau::Tableau2))
+        .copied()
+        .unwrap_or_default();
+    (t2.x - t1.x).abs()
+}
+
+/// Font size as a fraction of card width.
+const FONT_SIZE_FRAC: f32 = 0.28;
+
+/// Font-size fraction for the large-print readability overlay on touch HUD layouts.
+/// Spawned on top of PNG face cards to make the rank+suit legible at phone
+/// scale, where the baked-in PNG corner text is only ~10 px physical.
+const FONT_SIZE_FRAC_MOBILE: f32 = 0.35;
+
+/// Card-face background — Terminal `#1a1a1a` (BG_ELEVATED).
+pub const CARD_FACE_COLOUR: Color = Color::srgb(0.102, 0.102, 0.102);
+/// Suit colour for hearts + diamonds — saturated red `#e35353`.
+/// 2-colour traditional pairing (the "Microsoft Solitaire on dark
+/// mode" feel) replacing the brief 4-colour-deck experiment that
+/// shipped between v0.21.0 and this commit. Brighter and more
+/// saturated than the v0.21.0 pink `#fb9fb1` so the cards read as
+/// a "real solitaire deck" rather than a Terminal-pastel theme.
+/// Visually distinct from `ACCENT_PRIMARY` (`#a54242` brick red,
+/// darker) so chrome and suit don't read as the same hue.
+pub const RED_SUIT_COLOUR: Color = Color::srgb(0.890, 0.325, 0.325);
+/// High-contrast variant of [`RED_SUIT_COLOUR`] — `#ff6868`. Lifted
+/// luminance for the Settings → Accessibility → High-contrast mode
+/// toggle. Pre-2-colour-revert this was `#ff8aa0` (pink-salmon)
+/// matching the v0.21.0 pink default; rebumped to a brighter red
+/// so it reads as "more chromatic" than the new saturated default,
+/// not "less saturated." Independent of `RED_SUIT_COLOUR_CBM`
+/// (lime) — high-contrast is *additive* over the default colour
+/// palette; CBM is a *replacement* of red with a hue-distinct
+/// alternative. The two modes can stack; CBM wins when both are on
+/// because the CBM lime is itself a high-contrast colour.
+pub const RED_SUIT_COLOUR_HC: Color = Color::srgb(1.000, 0.408, 0.408);
+/// Suit colour for spades + clubs — near-white `#e8e8e8`. Brighter
+/// than `TEXT_PRIMARY` (`#d0d0d0`, foreground gray) so the
+/// "black suit" reads as a distinct, chromatic-neutral counterpart
+/// to the new saturated red, not as "the same gray as body text."
+/// `TEXT_PRIMARY_HC` (`#f5f5f5`) is still brighter for the
+/// high-contrast boost path.
+pub const BLACK_SUIT_COLOUR: Color = Color::srgb(0.910, 0.910, 0.910);
+
+/// Pre-loaded [`Handle<Image>`]s for card face and back PNG textures.
+///
+/// Loaded once at startup by [`load_card_images`].  When this resource is
+/// present, card sprites use the PNG artwork; otherwise they fall back to
+/// solid-colour sprites (used in tests with `MinimalPlugins`).
+#[derive(Resource)]
+pub struct CardImageSet {
+    /// Per-card face images indexed by `[suit][rank]`.
+    ///
+    /// Suit order: Clubs=0, Diamonds=1, Hearts=2, Spades=3.
+    /// Rank order: Ace=0, Two=1 … King=12.
+    pub faces: [[Handle<Image>; 13]; 4],
+    /// One handle per unlockable card-back design (indices 0–4). These
+    /// correspond to the legacy `assets/cards/backs/back_N.png` art, indexed
+    /// by `Settings::selected_card_back`. Used as a fallback when the active
+    /// theme does not provide its own back (see [`Self::theme_back`]).
+    pub backs: [Handle<Image>; 5],
+    /// Back image supplied by the currently-active card theme, if any.
+    ///
+    /// Populated by `theme::plugin::apply_theme_to_card_image_set` whenever
+    /// a `CardTheme` finishes loading. The face-down render path in
+    /// [`card_sprite`] prefers this handle over the legacy `backs[]` array,
+    /// so a theme switch swaps both faces *and* the back without the player
+    /// needing to touch the legacy `selected_card_back` picker. `None` means
+    /// the active theme did not declare a back asset (or no theme has loaded
+    /// yet); in that case [`card_sprite`] falls back to the legacy array.
+    pub theme_back: Option<Handle<Image>>,
+}
+
+/// Suit-colour swap for red-suit cards in colour-blind mode — Terminal
+/// `#acc267` (lime). Replaces `RED_SUIT_COLOUR` (pink) when CBM is on,
+/// providing a hue-distinct alternative that survives the most common
+/// red/green deficiencies. Pre-Terminal this was a *face tint*; the new
+/// design moves CBM differentiation into the suit glyph colour itself
+/// and keeps the face uniformly `CARD_FACE_COLOUR` regardless of CBM.
+///
+/// The CBM swap is lime (not the `ACCENT_PRIMARY` brick-red) because
+/// the primary accent is itself in the red family — using it for
+/// "the not-red CBM alternative" would defeat the purpose. Lime is
+/// the next-best non-red base16-eighties accent; deuteranopia and
+/// protanopia readers see it as visibly distinct from pink.
+const RED_SUIT_COLOUR_CBM: Color = Color::srgb(0.675, 0.761, 0.404);
+
+/// Returns the fallback card-back colour for the given unlocked card-back
+/// index. Production renders backs from PNG artwork; this fallback only
+/// fires under `MinimalPlugins` (tests). Mirrors the 5 accent colours
+/// from `card_face_svg::BACK_ACCENTS` so the test-environment back lives
+/// in the same hue family as the on-disk PNG art for that index.
+fn card_back_colour(selected_card_back: usize) -> Color {
+    match selected_card_back {
+        0 => Color::srgb(0.647, 0.259, 0.259), // #a54242 brick red (Terminal canonical, ACCENT_PRIMARY)
+        1 => Color::srgb(0.675, 0.761, 0.404), // #acc267 lime
+        2 => Color::srgb(0.882, 0.639, 0.933), // #e1a3ee lavender
+        3 => Color::srgb(0.984, 0.624, 0.694), // #fb9fb1 pink
+        _ => Color::srgb(0.867, 0.698, 0.435), // #ddb26f gold (4+)
+    }
+}
+
+/// Marker component linking a Bevy entity to its `solitaire_core::Card`.
+#[derive(Component, Debug, Clone)]
+pub struct CardEntity {
+    pub card: Card,
+}
+
+/// Cached signature of the inputs that determine a card entity's *child*
+/// visuals (drop-shadow, border frame, and the rank/suit label / large-print
+/// corner overlay). Stored on each card so [`update_card_entity`] can skip the
+/// expensive `despawn_related::<Children>()` + child respawn when nothing about
+/// the appearance changed — the common case during a move, where only the
+/// card's position changes. Without this guard every `StateChangedEvent`
+/// rebuilds all 52 cards' children (≈250 entity spawn/despawns plus 52 `Text2d`
+/// glyph re-layouts) in a single frame, which stutters the slide animation on
+/// high-resolution devices.
+///
+/// The children depend only on these four inputs; the card identity is fixed
+/// per entity, and the face/back *image* is handled by the always-refreshed
+/// `Sprite` (a cheap handle swap), so theme/card-back changes need no child
+/// rebuild.
+#[derive(Component, Clone, Copy, PartialEq)]
+struct CardChildrenKey {
+    face_up: bool,
+    card_size: Vec2,
+    color_blind: bool,
+    high_contrast: bool,
+}
+
+/// Query data read by the card-sync systems for each live card entity:
+/// its id, card identity, current transform, any in-flight curve animation,
+/// and its cached child-appearance key. Factored into an alias to keep the
+/// system signatures readable (and satisfy clippy's `type_complexity`).
+type CardSyncData = (
+    Entity,
+    &'static CardEntity,
+    &'static Transform,
+    Option<&'static CardAnimation>,
+    Option<&'static CardChildrenKey>,
+);
+
+/// Render-side index mapping each live board card to its [`CardEntity`].
+///
+/// Maintained exclusively by [`rebuild_card_entity_index`] in `PostUpdate`,
+/// after the card-sync authority ([`sync_cards_on_change`]) and the resize
+/// re-snap have flushed their spawn/despawn `Commands`. Consumers treat it as
+/// read-only and must still call `Query::get(entity)` for components beyond the
+/// `Entity` id (the map yields only the id).
+///
+/// Keyed by `Card`, which is unique across all live board entities in
+/// single-deck Klondike. Transient entities (drag shadow, labels) carry no
+/// `CardEntity` component, so the rebuild — which scans `&CardEntity` — never
+/// records them.
+#[derive(Resource, Debug, Default)]
+pub struct CardEntityIndex(pub HashMap<Card, Entity>);
+
+impl CardEntityIndex {
+    /// Resolve a card to its live entity, if one is currently spawned.
+    #[inline]
+    pub fn get(&self, card: &Card) -> Option<Entity> {
+        self.0.get(card).copied()
+    }
+}
+
+/// Marker for the text child inside a card entity.
+#[derive(Component, Debug)]
+pub struct CardLabel;
+
+/// Marker for the large-print rank+suit corner overlay used by touch HUD layouts.
+///
+/// Spawned on top of PNG face cards (face-up only) at font size
+/// [`FONT_SIZE_FRAC_MOBILE`] so the rank and suit character are
+/// readable at phone scale. Only exists when `CardImageSet` is present
+/// (the fallback solid-colour path uses a plain `CardLabel` instead).
+#[derive(Component, Debug, Clone)]
+struct AndroidCornerLabel(pub String);
+
+/// Solid-colour background sprite behind [`AndroidCornerLabel`].
+///
+/// Covers the card art's own small corner rank/suit text so only the
+/// large overlay is visible. Sized at [`FONT_SIZE_FRAC_MOBILE`]-derived
+/// dimensions and coloured [`CARD_FACE_COLOUR`] to match the card face.
+#[derive(Component, Debug, Clone, Copy)]
+struct AndroidCornerBg;
+
+type AndroidCornerBgFilter = (With<AndroidCornerBg>, Without<AndroidCornerLabel>);
+
+/// Marker component indicating the card is currently highlighted as a hint.
+/// `remaining` counts down in real seconds; the highlight is removed when it
+/// reaches zero and the card sprite colour is restored to its normal value.
+#[derive(Component, Debug, Clone)]
+pub struct HintHighlight {
+    /// Seconds remaining before the highlight is cleared.
+    pub remaining: f32,
+}
+
+/// Countdown (seconds) until the `HintHighlight` on a card entity is removed.
+///
+/// Inserted alongside `HintHighlight` by the hint-visual system. When the timer
+/// reaches zero both `HintHighlight` and `HintHighlightTimer` are removed from
+/// the entity and the sprite colour is restored.
+#[derive(Component, Debug, Clone)]
+pub struct HintHighlightTimer(pub f32);
+
+/// Marker on a `PileMarker` entity that is highlighted because the right-clicked
+/// card can legally be placed there.
+#[derive(Component, Debug)]
+pub struct RightClickHighlight;
+
+/// Countdown (seconds) until this right-click destination highlight despawns.
+///
+/// Inserted alongside `RightClickHighlight` so that highlights auto-clear after
+/// 1.5 s even if the player does not make a move or click again. The existing
+/// clear-on-state-change and clear-on-pause logic still fires early when
+/// appropriate.
+#[derive(Component, Debug, Clone)]
+pub struct RightClickHighlightTimer(pub f32);
+
+/// Marker placed on the child `Text2d` entity that shows "↺" on the stock pile
+/// marker when the stock pile is empty.
+#[derive(Component, Debug)]
+pub struct StockEmptyLabel;
+
+/// Marker on the chip-background sprite of the stock-pile remaining-count
+/// badge.
+///
+/// The badge is spawned as a *top-level* world entity (not parented to the
+/// stock [`PileMarker`]) and its `Transform` is recomputed each frame from
+/// `LayoutResource` so it tracks the stock pile through window resizes.
+/// The chip sits in the bottom-right corner of the stock pile and is hidden
+/// while the stock is empty — the existing `↺` overlay
+/// ([`StockEmptyLabel`]) covers the recycle hint instead, so the two
+/// indicators never render simultaneously.
+#[derive(Component, Debug)]
+pub struct StockCountBadge;
+
+/// Marker on the `Text2d` child of [`StockCountBadge`] showing the numeric
+/// count of cards remaining in the stock pile.
+///
+/// Update systems query this component to write the new count in place rather
+/// than despawning and respawning the text entity each tick.
+#[derive(Component, Debug)]
+pub struct StockCountBadgeText;
+
+// ---------------------------------------------------------------------------
+// Task #34 — Card-flip animation
+// ---------------------------------------------------------------------------
+
+/// Phase of the two-stage flip animation.
+#[derive(Debug, Clone, PartialEq)]
+pub enum FlipPhase {
+    /// Scale X from 1.0 → 0.0 (hiding the back face).
+    ScalingDown,
+    /// Scale X from 0.0 → 1.0 (revealing the front face).
+    ScalingUp,
+}
+
+/// Drives a 2-phase "card flip" animation on `CardEntity` entities.
+///
+/// The animation squashes X to 0, swaps the sprite to the face-up colour,
+/// then expands X back to 1. Total duration is `2 × FLIP_HALF_SECS`.
+#[derive(Component, Debug, Clone)]
+pub struct CardFlipAnim {
+    /// Seconds elapsed in the current phase.
+    pub timer: f32,
+    /// Which half of the flip we are in.
+    pub phase: FlipPhase,
+}
+
+/// Duration of each half of the flip animation (scale-down or scale-up).
+const FLIP_HALF_SECS: f32 = 0.08;
+
+// ---------------------------------------------------------------------------
+// Task #38 — Drag-elevation shadow
+// ---------------------------------------------------------------------------
+
+/// Marker component for the semi-transparent shadow sprite shown while dragging.
+#[derive(Component, Debug)]
+pub struct ShadowEntity;
+
+/// Marker component for the per-card drop-shadow child sprite.
+///
+/// Every `CardEntity` owns exactly one `CardShadow` child whose `Sprite` is a
+/// neutral-black halo painted slightly down-and-right of the card. Idle state
+/// uses [`CARD_SHADOW_OFFSET_IDLE`] / [`CARD_SHADOW_ALPHA_IDLE`]; while the
+/// parent card is being dragged the shadow is pushed to the deeper
+/// [`CARD_SHADOW_OFFSET_DRAG`] / [`CARD_SHADOW_ALPHA_DRAG`] values so the
+/// stack reads as "lifted" off the felt.
+#[derive(Component, Debug)]
+pub struct CardShadow;
+
+/// Marker on the thin contrasting border sprite spawned behind face-down cards.
+///
+/// Face-down cards use `back_0.png` which is near-black (`#1a1a1a`). On the
+/// dark-green felt the edges are nearly invisible. This child sprite — slightly
+/// larger than the card, rendered at local z=-0.01 so it peeks out as a thin
+/// frame — gives every face-down card a visible perimeter.
+#[derive(Component, Debug)]
+pub struct CardBackFrame;
+
+/// Fill colour for the face-down card border frame. Light-medium gray so it
+/// reads as a clear "edge" without competing with the suit colours on face-up
+/// cards. Brightened from `0.38` to `0.48` (≈ #7a7a7a) after a Pixel_7 smoke
+/// test showed face-down `back_0.png` (≈ #1a1a1a) was nearly invisible against
+/// the very dark `#151515` felt — the old gray was too close to the back fill
+/// to define a crisp perimeter.
+const CARD_BACK_FRAME_COLOR: Color = Color::srgb(0.48, 0.48, 0.48);
+
+/// Extra width/height (in world units) added to each side of the card to form
+/// the visible border. Widened from `3.0` to `6.0` so the frame peeks out as a
+/// clearly readable perimeter at phone density (420 dpi) rather than a hairline.
+const CARD_BACK_FRAME_PADDING: f32 = 6.0;
+
+/// Returns the `(offset, padding, alpha)` triple used to paint a per-card
+/// shadow given whether its parent card is currently part of the dragged
+/// stack. Pulled out as a pure helper so the shadow tuning can be unit-tested
+/// without spinning up a Bevy app.
+///
+/// `is_dragged = false` → resting `(IDLE, IDLE, IDLE)`
+/// `is_dragged = true`  → lifted  `(DRAG, DRAG, DRAG)`
+pub fn card_shadow_params(is_dragged: bool) -> (Vec2, Vec2, f32) {
+    if is_dragged {
+        (
+            CARD_SHADOW_OFFSET_DRAG,
+            CARD_SHADOW_PADDING_DRAG,
+            CARD_SHADOW_ALPHA_DRAG,
+        )
+    } else {
+        (
+            CARD_SHADOW_OFFSET_IDLE,
+            CARD_SHADOW_PADDING_IDLE,
+            CARD_SHADOW_ALPHA_IDLE,
+        )
+    }
+}
+
+/// Builds the `Sprite` used for a per-card shadow at the resting state. The
+/// alpha and size both use the idle tokens; `update_card_shadows_on_drag`
+/// retunes them at runtime when the parent card joins / leaves the dragged
+/// stack.
+fn card_shadow_sprite(card_size: Vec2) -> Sprite {
+    let (_offset, padding, alpha) = card_shadow_params(false);
+    Sprite {
+        color: CARD_SHADOW_COLOR.with_alpha(alpha),
+        custom_size: Some(card_size + padding),
+        ..default()
+    }
+}
+
+/// Builds the `Transform` used for a per-card shadow at the resting state.
+/// Local — it is parented to the card entity, so positions are relative.
+fn card_shadow_transform() -> Transform {
+    let (offset, _padding, _alpha) = card_shadow_params(false);
+    Transform::from_xyz(offset.x, offset.y, CARD_SHADOW_LOCAL_Z)
+}
+
+/// Spawns a single `CardShadow` child under the given card entity builder.
+/// Extracted so `spawn_card_entity` and `update_card_entity` can share the
+/// exact same shadow recipe — we never want one path to drift from the other.
+fn add_card_shadow_child(parent: &mut ChildSpawnerCommands, card_size: Vec2) {
+    parent.spawn((
+        CardShadow,
+        card_shadow_sprite(card_size),
+        card_shadow_transform(),
+        Visibility::default(),
+    ));
+}
+
+/// Spawns a `CardBackFrame` child behind a card entity to give every card a
+/// thin perimeter against the dark felt, regardless of face state.
+fn add_card_back_frame_child(parent: &mut ChildSpawnerCommands, card_size: Vec2) {
+    parent.spawn((
+        CardBackFrame,
+        Sprite {
+            color: CARD_BACK_FRAME_COLOR,
+            custom_size: Some(card_size + Vec2::splat(CARD_BACK_FRAME_PADDING)),
+            ..default()
+        },
+        Transform::from_xyz(0.0, 0.0, -0.01),
+        Visibility::default(),
+    ));
+}
+
+/// Throttle interval for resize-driven card snap work, in seconds.
+///
+/// `WindowResized` fires once per pixel of drag, so a fast corner-drag can
+/// produce dozens of events per frame. Re-running the per-card snap logic
+/// (52 cards × sprite/transform/font_size touches) for every event is the
+/// dominant cost of resize lag. We coalesce pending work and apply it at most
+/// once per [`RESIZE_THROTTLE_SECS`] (~20 Hz). The user still sees updates
+/// during a sustained drag, and the layout always catches up to the final
+/// size when the drag stops because the pending size is held until applied.
+const RESIZE_THROTTLE_SECS: f32 = 0.05;
+
+/// Holds the latest pending window size from `WindowResized` events plus a
+/// timestamp for the last applied snap, so the resize-snap work can be
+/// rate-limited to ~20 Hz during sustained drags.
+#[derive(Resource, Debug, Default)]
+pub struct ResizeThrottle {
+    /// Latest unapplied window size from `WindowResized`. `None` when there is
+    /// nothing to apply.
+    pub pending: Option<Vec2>,
+    /// `Time::elapsed_secs()` value at the moment of the most recent applied
+    /// snap. `0.0` until the first apply.
+    pub last_applied_secs: f32,
+}
+
+/// Pure helper used by the throttled resize-snap system: returns `true` when
+/// a pending resize should be flushed given the current `now_secs` and the
+/// last-applied timestamp. Throttle interval is [`RESIZE_THROTTLE_SECS`].
+///
+/// Extracted so the rate-limit logic can be unit-tested without spinning up
+/// a full Bevy app.
+fn should_apply_resize(now_secs: f32, last_applied_secs: f32) -> bool {
+    (now_secs - last_applied_secs) >= RESIZE_THROTTLE_SECS
+}
+
+/// Renders cards by reading `GameStateResource` on `StateChangedEvent`.
+pub struct CardPlugin;
+
+impl Plugin for CardPlugin {
+    fn build(&self, app: &mut App) {
+        // PostStartup ensures TablePlugin's Startup system has inserted
+        // LayoutResource before we try to read it.
+        //
+        // `handle_right_click` reads `ButtonInput<MouseButton>`. Under
+        // `MinimalPlugins` (tests) this resource is absent by default, so we
+        // ensure it exists here. Under `DefaultPlugins` the call is a no-op.
+        app.init_resource::<ButtonInput<MouseButton>>()
+            .init_resource::<ResizeThrottle>()
+            .init_resource::<CardEntityIndex>()
+            .add_message::<SettingsChangedEvent>()
+            .add_message::<CardFlippedEvent>()
+            .add_message::<CardFaceRevealedEvent>()
+            .add_systems(Startup, load_card_images)
+            .add_systems(
+                PostStartup,
+                (
+                    // Fill the tableau fan before the first render so the
+                    // cold-start deal already uses the full viewport height.
+                    fill_tableau_fan_on_startup.before(sync_cards_startup),
+                    sync_cards_startup,
+                    update_stock_empty_indicator_startup,
+                ),
+            )
+            .add_systems(
+                Update,
+                (
+                    update_tableau_fan_frac
+                        .after(GameMutation)
+                        .before(sync_cards_on_change),
+                    sync_cards_on_change.after(GameMutation),
+                    resync_cards_on_settings_change.before(sync_cards_on_change),
+                    start_flip_anim.after(GameMutation),
+                    tick_flip_anim,
+                    update_drag_shadow,
+                    update_card_shadows_on_drag.after(sync_cards_on_change),
+                    tick_hint_highlight,
+                    handle_right_click,
+                    tick_right_click_highlights,
+                    clear_right_click_highlights_on_state_change.after(GameMutation),
+                    clear_right_click_highlights_on_pause,
+                    update_stock_empty_indicator.after(GameMutation),
+                    update_stock_count_badge
+                        .after(GameMutation)
+                        .run_if(resource_changed::<GameStateResource>),
+                    collect_resize_events.after(LayoutSystem::UpdateOnResize),
+                    snap_cards_on_window_resize.after(collect_resize_events),
+                ),
+            );
+
+        app.add_systems(Update, resize_android_corner_labels);
+        app.add_systems(PostUpdate, rebuild_card_entity_index);
+    }
+}
+
+#[cfg(test)]
+mod tests;

solitaire_engine/src/card_plugin/stock.rs

@@ -0,0 +1,291 @@
+//! Stock-pile indicators: the empty-stock recycle hint and count badge.
+
+use super::*;
+
+
+use bevy::color::Color;
+use solitaire_core::KlondikePile;
+use solitaire_core::game_state::GameState;
+
+use crate::events::StateChangedEvent;
+use crate::font_plugin::FontResource;
+use crate::layout::{Layout, LayoutResource};
+use crate::resources::GameStateResource;
+use crate::table_plugin::{PILE_MARKER_DEFAULT_COLOUR, PileMarker};
+use crate::ui_theme::{
+    STOCK_BADGE_BG, STOCK_BADGE_FG, TEXT_PRIMARY,
+    TYPE_BODY, Z_STOCK_BADGE,
+};
+
+/// Sprite colour applied to the stock `PileMarker` when the stock pile is empty,
+/// to signal to the player that there are no more cards to draw. Pure white
+/// at 0.4 alpha — a deliberate brightness-boost over the default marker so
+/// the "empty" state is more visible, not less. Not derived from a palette
+/// token: this is a sprite tint, not chrome colour.
+const STOCK_EMPTY_DIM_COLOUR: Color = Color::srgba(1.0, 1.0, 1.0, 0.4);
+
+/// Sprite colour applied to the stock `PileMarker` when cards remain in
+/// stock. Aliased to [`PILE_MARKER_DEFAULT_COLOUR`] so it tracks the rest
+/// of the engine's idle pile-marker tint automatically.
+const STOCK_NORMAL_COLOUR: Color = PILE_MARKER_DEFAULT_COLOUR;
+
+/// Shared logic for updating the stock pile marker's dim state and "↺" label.
+///
+/// If the stock pile is empty the marker sprite is dimmed to
+/// `STOCK_EMPTY_DIM_COLOUR` and a child `Text2d` with `StockEmptyLabel` is
+/// spawned (if not already present). When the stock is non-empty the marker is
+/// restored to `STOCK_NORMAL_COLOUR` and any `StockEmptyLabel` children are
+/// despawned.
+pub(super) fn apply_stock_empty_indicator<F: bevy::ecs::query::QueryFilter>(
+    commands: &mut Commands,
+    game: &GameState,
+    pile_markers: &mut Query<(Entity, &PileMarker, &mut Sprite), F>,
+    label_children: &Query<(Entity, &ChildOf), With<StockEmptyLabel>>,
+    layout: &Layout,
+    font: Handle<Font>,
+) {
+    let stock_empty = game.stock_cards().is_empty();
+
+    for (entity, pile_marker, mut sprite) in pile_markers.iter_mut() {
+        if pile_marker.0 != KlondikePile::Stock {
+            continue;
+        }
+
+        if stock_empty {
+            // Dim the marker sprite.
+            sprite.color = STOCK_EMPTY_DIM_COLOUR;
+
+            // Spawn the "↺" label only if one does not already exist.
+            let already_has_label = label_children
+                .iter()
+                .any(|(_, parent)| parent.parent() == entity);
+            if !already_has_label {
+                let font_size = layout.card_size.x * 0.4;
+                commands.entity(entity).with_children(|b| {
+                    b.spawn((
+                        StockEmptyLabel,
+                        Text2d::new("↺"),
+                        TextFont {
+                            font: font.clone(),
+                            font_size,
+                            ..default()
+                        },
+                        TextColor(TEXT_PRIMARY.with_alpha(0.7)),
+                        Transform::from_xyz(0.0, 0.0, 0.1),
+                    ));
+                });
+            }
+        } else {
+            // Restore normal brightness.
+            sprite.color = STOCK_NORMAL_COLOUR;
+
+            // Despawn any existing "↺" label children.
+            for (label_entity, parent) in label_children.iter() {
+                if parent.parent() == entity {
+                    commands.entity(label_entity).despawn();
+                }
+            }
+        }
+    }
+}
+
+/// Runs at `PostStartup` to apply the stock-empty indicator for the initial
+/// game state (before any `StateChangedEvent` fires).
+pub(super) fn update_stock_empty_indicator_startup(
+    mut commands: Commands,
+    game: Res<GameStateResource>,
+    layout: Option<Res<LayoutResource>>,
+    font_res: Option<Res<FontResource>>,
+    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite)>,
+    label_children: Query<(Entity, &ChildOf), With<StockEmptyLabel>>,
+) {
+    let Some(layout) = layout else { return };
+    let font = font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default();
+    apply_stock_empty_indicator(
+        &mut commands,
+        &game.0,
+        &mut pile_markers,
+        &label_children,
+        &layout.0,
+        font,
+    );
+}
+
+/// Runs each `Update` tick when a `StateChangedEvent` arrives, keeping the
+/// stock pile marker dim state and "↺" label in sync with the current stock.
+pub(super) fn update_stock_empty_indicator(
+    mut events: MessageReader<StateChangedEvent>,
+    mut commands: Commands,
+    game: Res<GameStateResource>,
+    layout: Option<Res<LayoutResource>>,
+    font_res: Option<Res<FontResource>>,
+    mut pile_markers: Query<(Entity, &PileMarker, &mut Sprite)>,
+    label_children: Query<(Entity, &ChildOf), With<StockEmptyLabel>>,
+) {
+    if events.read().next().is_none() {
+        return;
+    }
+    let Some(layout) = layout else { return };
+    let font = font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default();
+    apply_stock_empty_indicator(
+        &mut commands,
+        &game.0,
+        &mut pile_markers,
+        &label_children,
+        &layout.0,
+        font,
+    );
+}
+
+// ---------------------------------------------------------------------------
+// Stock-pile remaining-count badge
+//
+// Shows a small "N" chip pinned to the bottom-right corner of the stock pile so
+// the player can see how many cards remain before the next recycle. The
+// existing `StockEmptyLabel` (`↺` overlay) covers the empty-stock case, so
+// the badge hides itself when the stock has zero cards — the two indicators
+// never render at the same time.
+// ---------------------------------------------------------------------------
+
+/// Inset (in pixels) from the bottom-right corner of the stock pile sprite to
+/// the centre of the count badge. Anchoring to the bottom-right keeps the chip
+/// clear of the rank/suit pip in the card's top-left corner. Both components
+/// move the centre *inward* from that corner: `x` is subtracted from the right
+/// edge, `y` is added to the bottom edge. The `x` magnitude must satisfy
+/// `x >= STOCK_BADGE_SIZE.x / 2` so the badge right edge stays inside the stock
+/// pile and never overlaps the adjacent waste pile — critical on Android where
+/// `H_GAP_DIVISOR = 32` gives an inter-pile gap of only ~4 px.
+const STOCK_BADGE_INSET: Vec2 = Vec2::new(20.0, 8.0);
+
+/// Width / height of the badge background sprite, in world pixels. Sized so
+/// a 2-digit count (max "24") fits comfortably with `TYPE_BODY` (14 pt) text.
+const STOCK_BADGE_SIZE: Vec2 = Vec2::new(34.0, 20.0);
+
+/// Returns the count of cards currently in the stock pile.
+///
+/// Pure helper extracted so the count source is identical between the spawn
+/// system, the update system, and the unit tests.
+pub(super) fn stock_card_count(game: &GameState) -> usize {
+    game.stock_cards().len()
+}
+
+/// Returns the world-space `Vec3` for the centre of the stock-count badge,
+/// given the current `Layout`. The badge sits at the bottom-right corner of
+/// the stock pile sprite, inset by [`STOCK_BADGE_INSET`], so it stays clear of
+/// the rank/suit pip in the card's top-left corner.
+pub(super) fn stock_badge_translation(layout: &Layout) -> Vec3 {
+    // Empty layouts don't contain a Stock entry — fall back to origin so
+    // the badge stays in a deterministic spot until the layout is filled.
+    let pile_pos = layout
+        .pile_positions
+        .get(&KlondikePile::Stock)
+        .copied()
+        .unwrap_or(Vec2::ZERO);
+    let half = layout.card_size * 0.5;
+    // Anchor to the bottom-right corner, then move the centre inward.
+    let x = pile_pos.x + half.x - STOCK_BADGE_INSET.x;
+    let y = pile_pos.y - half.y + STOCK_BADGE_INSET.y;
+    Vec3::new(x, y, Z_STOCK_BADGE)
+}
+
+/// Spawns the stock-count badge entity (background sprite + child text)
+/// into the world. Called once, when the badge does not yet exist.
+pub(super) fn spawn_stock_count_badge(
+    commands: &mut Commands,
+    layout: &Layout,
+    font: Option<&Handle<Font>>,
+    count: usize,
+) {
+    let translation = stock_badge_translation(layout);
+    let visibility = if count == 0 {
+        Visibility::Hidden
+    } else {
+        Visibility::Inherited
+    };
+    let text_font = TextFont {
+        font: font.cloned().unwrap_or_default(),
+        font_size: TYPE_BODY,
+        ..default()
+    };
+
+    commands
+        .spawn((
+            StockCountBadge,
+            Sprite {
+                color: STOCK_BADGE_BG,
+                custom_size: Some(STOCK_BADGE_SIZE),
+                ..default()
+            },
+            Transform::from_translation(translation),
+            visibility,
+        ))
+        .with_children(|b| {
+            b.spawn((
+                StockCountBadgeText,
+                Text2d::new(format!("{count}")),
+                text_font,
+                TextColor(STOCK_BADGE_FG),
+                // Slightly above the chip background so the digits aren't
+                // occluded by the sprite they sit on.
+                Transform::from_xyz(0.0, 0.0, 0.1),
+            ));
+        });
+}
+
+/// Spawns the stock-pile remaining-count badge if it does not yet exist,
+/// and otherwise updates its text and visibility in place.
+///
+/// Visibility rule: hidden when the stock is empty (the existing `↺`
+/// `StockEmptyLabel` overlay covers that state), shown when one or more
+/// cards remain.
+///
+/// Position is recomputed from `LayoutResource` every tick so the badge
+/// follows the stock pile across `WindowResized` layout updates without
+/// needing a dedicated resize handler.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn update_stock_count_badge(
+    mut commands: Commands,
+    game: Option<Res<GameStateResource>>,
+    layout: Option<Res<LayoutResource>>,
+    font: Option<Res<FontResource>>,
+    mut badges: Query<(Entity, &mut Transform, &mut Visibility), With<StockCountBadge>>,
+    children: Query<&Children, With<StockCountBadge>>,
+    mut texts: Query<&mut Text2d, With<StockCountBadgeText>>,
+) {
+    let Some(game) = game else { return };
+    let Some(layout) = layout else { return };
+
+    let count = stock_card_count(&game.0);
+    let translation = stock_badge_translation(&layout.0);
+    let target_visibility = if count == 0 {
+        Visibility::Hidden
+    } else {
+        Visibility::Inherited
+    };
+
+    if badges.is_empty() {
+        spawn_stock_count_badge(&mut commands, &layout.0, font.as_ref().map(|f| &f.0), count);
+        return;
+    }
+
+    for (entity, mut transform, mut visibility) in badges.iter_mut() {
+        transform.translation = translation;
+        if *visibility != target_visibility {
+            *visibility = target_visibility;
+        }
+        // Update the child text to reflect the latest count. The text node
+        // is created at spawn time, so under normal operation we always
+        // have exactly one child here.
+        if let Ok(badge_children) = children.get(entity) {
+            for child in badge_children.iter() {
+                if let Ok(mut text) = texts.get_mut(child) {
+                    let new = format!("{count}");
+                    if text.0 != new {
+                        text.0 = new;
+                    }
+                }
+            }
+        }
+    }
+}
+

solitaire_engine/src/card_plugin/sync.rs

@@ -0,0 +1,748 @@
+//! Card asset loading and entity lifecycle: the sync systems that
+//! spawn, update, and position card entities from `GameStateResource`.
+
+use super::*;
+
+use std::collections::{HashMap, HashSet};
+
+use bevy::color::Color;
+use solitaire_core::{Foundation, KlondikePile, Tableau};
+use solitaire_core::{Card, Rank, Suit};
+use solitaire_core::{DrawStockConfig, game_state::GameState};
+
+use crate::animation_plugin::{CARD_ANIM_Z_LIFT, CardAnim, EffectiveSlideDuration};
+use crate::card_animation::CardAnimation;
+use crate::events::StateChangedEvent;
+use crate::font_plugin::FontResource;
+use crate::layout::{Layout, LayoutResource};
+use crate::platform::USE_TOUCH_UI_LAYOUT;
+use crate::resources::GameStateResource;
+use crate::settings_plugin::{SettingsChangedEvent, SettingsResource};
+
+/// Rebuild the [`CardEntityIndex`] from the live `CardEntity` set.
+///
+/// Runs in `PostUpdate` so that all spawn/despawn `Commands` issued by
+/// [`sync_cards_on_change`] and [`snap_cards_on_window_resize`] in `Update`
+/// have been flushed at the `Update -> PostUpdate` apply-deferred boundary.
+/// Rebuilding from scratch (rather than incrementally patching at every
+/// spawn/despawn site — waste cards churn on every draw) keeps a single writer
+/// and makes a stale entry structurally impossible.
+///
+/// Gated to changed frames only: `Changed<CardEntity>` fires the frame a card
+/// is spawned, `RemovedComponents<CardEntity>` the frame one is despawned. The
+/// `card` field is write-once (never mutated in place), so card-reposition
+/// frames don't trip `Changed` and correctly skip the O(52) rebuild.
+pub(super) fn rebuild_card_entity_index(
+    mut index: ResMut<CardEntityIndex>,
+    cards: Query<(Entity, &CardEntity)>,
+    changed: Query<(), Changed<CardEntity>>,
+    removed: RemovedComponents<CardEntity>,
+) {
+    if changed.is_empty() && removed.is_empty() {
+        return;
+    }
+    let map = &mut index.0;
+    map.clear();
+    for (entity, ce) in &cards {
+        map.insert(ce.card.clone(), entity);
+    }
+}
+
+/// Returns the relative asset path for a card face PNG.
+///
+/// The path format is `cards/faces/classic/{RANK}{SUIT}.png`, e.g. `QS.png`
+/// for the Queen of Spades. Both `load_card_images` and the unit tests use
+/// this function so the filename formula is tested in isolation from the
+/// asset-loading machinery.
+///
+/// Note: this function verifies only the **code-side mapping**. If the PNG
+/// file at the returned path contains wrong artwork (e.g. `QS.png` has a
+/// diamond watermark baked in), that is an **asset content bug** and must be
+/// fixed by replacing the file — no code change can correct it.
+pub(super) fn card_face_asset_path(rank: Rank, suit: Suit) -> String {
+    const SUIT_CHARS: [&str; 4] = ["C", "D", "H", "S"];
+    const RANK_STRS: [&str; 13] = [
+        "A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K",
+    ];
+    let suit_idx = match suit {
+        Suit::Clubs => 0,
+        Suit::Diamonds => 1,
+        Suit::Hearts => 2,
+        Suit::Spades => 3,
+    };
+    let rank_idx = match rank {
+        Rank::Ace => 0,
+        Rank::Two => 1,
+        Rank::Three => 2,
+        Rank::Four => 3,
+        Rank::Five => 4,
+        Rank::Six => 5,
+        Rank::Seven => 6,
+        Rank::Eight => 7,
+        Rank::Nine => 8,
+        Rank::Ten => 9,
+        Rank::Jack => 10,
+        Rank::Queen => 11,
+        Rank::King => 12,
+    };
+    format!(
+        "cards/faces/classic/{}{}.png",
+        RANK_STRS[rank_idx], SUIT_CHARS[suit_idx]
+    )
+}
+
+/// Loads card face and back PNGs at startup via [`AssetServer`] and inserts
+/// [`CardImageSet`].
+///
+/// Faces: `assets/cards/faces/{RANK}{SUIT}.png`  (e.g. `AC.png`, `10H.png`)
+/// Backs: `assets/cards/backs/back_{0..4}.png`
+///
+/// Under `MinimalPlugins` (tests) `AssetServer` is absent, so the system
+/// returns without inserting `CardImageSet` and the plugin falls back to
+/// solid-colour sprites.
+pub(super) fn load_card_images(asset_server: Option<Res<AssetServer>>, mut commands: Commands) {
+    let Some(asset_server) = asset_server else {
+        return;
+    };
+
+    const SUITS: [Suit; 4] = [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades];
+    const RANKS: [Rank; 13] = [
+        Rank::Ace,
+        Rank::Two,
+        Rank::Three,
+        Rank::Four,
+        Rank::Five,
+        Rank::Six,
+        Rank::Seven,
+        Rank::Eight,
+        Rank::Nine,
+        Rank::Ten,
+        Rank::Jack,
+        Rank::Queen,
+        Rank::King,
+    ];
+
+    let faces: [[Handle<Image>; 13]; 4] = std::array::from_fn(|si| {
+        std::array::from_fn(|ri| asset_server.load(card_face_asset_path(RANKS[ri], SUITS[si])))
+    });
+    let backs =
+        std::array::from_fn(|i| asset_server.load(format!("cards/backs/classic/back_{i}.png")));
+    commands.insert_resource(CardImageSet {
+        faces,
+        backs,
+        // Populated by the theme plugin once a `CardTheme` finishes loading.
+        // Until then the legacy back fallback (`backs[selected_card_back]`)
+        // is used.
+        theme_back: None,
+    });
+}
+
+/// Builds the [`Sprite`] for a card, using PNG artwork when [`CardImageSet`] is
+/// available and falling back to a solid-colour sprite in tests.
+pub(super) fn card_sprite(
+    card: &Card,
+    face_up: bool,
+    card_size: Vec2,
+    back_colour: Color,
+    card_images: Option<&CardImageSet>,
+    selected_back: usize,
+) -> Sprite {
+    if let Some(set) = card_images {
+        let image = if face_up {
+            let suit_idx = match card.suit() {
+                Suit::Clubs => 0,
+                Suit::Diamonds => 1,
+                Suit::Hearts => 2,
+                Suit::Spades => 3,
+            };
+            let rank_idx = match card.rank() {
+                Rank::Ace => 0,
+                Rank::Two => 1,
+                Rank::Three => 2,
+                Rank::Four => 3,
+                Rank::Five => 4,
+                Rank::Six => 5,
+                Rank::Seven => 6,
+                Rank::Eight => 7,
+                Rank::Nine => 8,
+                Rank::Ten => 9,
+                Rank::Jack => 10,
+                Rank::Queen => 11,
+                Rank::King => 12,
+            };
+            set.faces[suit_idx][rank_idx].clone()
+        } else if let Some(theme_back) = &set.theme_back {
+            // Active theme provides its own back — always wins over the
+            // legacy `selected_card_back` picker, so a theme switch swaps
+            // faces *and* the back. The picker is treated as informational
+            // only while a theme back is active (see settings_plugin).
+            theme_back.clone()
+        } else {
+            let idx = selected_back.min(set.backs.len() - 1);
+            set.backs[idx].clone()
+        };
+        Sprite {
+            image,
+            color: Color::WHITE,
+            custom_size: Some(card_size),
+            ..default()
+        }
+    } else {
+        // Terminal aesthetic: face background is uniformly CARD_FACE_COLOUR
+        // regardless of colour-blind mode (CBM differentiation now lives in
+        // the suit glyph colour, applied by `text_colour`, not the face
+        // background). Pre-Terminal this branch dispatched through a
+        // separate `face_colour(card, color_blind)` helper.
+        let body_colour = if face_up {
+            CARD_FACE_COLOUR
+        } else {
+            back_colour
+        };
+        Sprite {
+            color: body_colour,
+            custom_size: Some(card_size),
+            ..default()
+        }
+    }
+}
+
+/// When card-back selection changes in Settings, re-render all cards so the
+/// new back colour is applied immediately (without waiting for a state change).
+pub(super) fn resync_cards_on_settings_change(
+    mut setting_events: MessageReader<SettingsChangedEvent>,
+    mut state_events: MessageWriter<StateChangedEvent>,
+) {
+    if setting_events.read().next().is_some() {
+        state_events.write(StateChangedEvent);
+    }
+}
+
+/// Render the initial deal. Runs in `PostStartup`, so all `Startup` systems
+/// (including `TablePlugin::setup_table` which inserts `LayoutResource`)
+/// have already completed.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn sync_cards_startup(
+    commands: Commands,
+    game: Res<GameStateResource>,
+    layout: Option<Res<LayoutResource>>,
+    slide_dur: Option<Res<EffectiveSlideDuration>>,
+    settings: Option<Res<SettingsResource>>,
+    entities: Query<CardSyncData>,
+    card_images: Option<Res<CardImageSet>>,
+    font_res: Option<Res<FontResource>>,
+) {
+    if let Some(layout) = layout {
+        let slide_secs = slide_dur.map_or(0.15, |d| d.slide_secs);
+        let selected_back = settings.as_ref().map_or(0, |s| s.0.selected_card_back);
+        let back_colour = card_back_colour(selected_back);
+        let color_blind = settings.as_ref().is_some_and(|s| s.0.color_blind_mode);
+        let high_contrast = settings.as_ref().is_some_and(|s| s.0.high_contrast_mode);
+        let font_handle = font_res.as_ref().map(|r| &r.0);
+        sync_cards(
+            commands,
+            &game.0,
+            &layout.0,
+            slide_secs,
+            back_colour,
+            color_blind,
+            high_contrast,
+            &entities,
+            card_images.as_deref(),
+            selected_back,
+            font_handle,
+        );
+    }
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(super) fn sync_cards_on_change(
+    mut events: MessageReader<StateChangedEvent>,
+    commands: Commands,
+    game: Res<GameStateResource>,
+    layout: Option<Res<LayoutResource>>,
+    slide_dur: Option<Res<EffectiveSlideDuration>>,
+    settings: Option<Res<SettingsResource>>,
+    entities: Query<CardSyncData>,
+    card_images: Option<Res<CardImageSet>>,
+    font_res: Option<Res<FontResource>>,
+) {
+    if events.read().next().is_none() {
+        return;
+    }
+    if let Some(layout) = layout {
+        let slide_secs = slide_dur.map_or(0.15, |d| d.slide_secs);
+        let selected_back = settings.as_ref().map_or(0, |s| s.0.selected_card_back);
+        let back_colour = card_back_colour(selected_back);
+        let color_blind = settings.as_ref().is_some_and(|s| s.0.color_blind_mode);
+        let high_contrast = settings.as_ref().is_some_and(|s| s.0.high_contrast_mode);
+        let font_handle = font_res.as_ref().map(|r| &r.0);
+        sync_cards(
+            commands,
+            &game.0,
+            &layout.0,
+            slide_secs,
+            back_colour,
+            color_blind,
+            high_contrast,
+            &entities,
+            card_images.as_deref(),
+            selected_back,
+            font_handle,
+        );
+    }
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(super) fn sync_cards(
+    mut commands: Commands,
+    game: &GameState,
+    layout: &Layout,
+    slide_secs: f32,
+    back_colour: Color,
+    color_blind: bool,
+    high_contrast: bool,
+    entities: &Query<CardSyncData>,
+    card_images: Option<&CardImageSet>,
+    selected_back: usize,
+    font_handle: Option<&Handle<Font>>,
+) {
+    let positions = card_positions(game, layout);
+
+    // The waste buffer card exists only to keep its entity alive while the new
+    // top card's slide animation plays — it must never be visible to the player.
+    // Without this, the buffer sits at waste_base uncovered during the animation
+    // and its rank/suit peek behind the incoming card.
+    let waste_buffer_id: Option<Card> = {
+        let visible = match game.draw_mode() {
+            DrawStockConfig::DrawOne => 1_usize,
+            DrawStockConfig::DrawThree => 3_usize,
+        };
+        let waste_cards = game.waste_cards();
+        (waste_cards.len() > visible)
+            .then_some(waste_cards)
+            .and_then(|w| w.get(w.len().saturating_sub(visible + 1)).cloned())
+            .map(|(c, _face_up)| c)
+    };
+
+    // Map Card -> (Entity, current_translation, anim_end) for in-place
+    // updates.  `anim_end` is `Some(end_xy)` when a curve-based `CardAnimation`
+    // is currently driving the card (e.g. a drag-rejection return tween).
+    //
+    // In the position loop below we compare `anim_end` against the new game-
+    // state target position to decide whether to honour or cancel the tween:
+    //   • end ≈ target  → animation is still heading to the right place; let
+    //                      it finish (skip the snap/slide path).
+    //   • end ≠ target  → the game state has changed (e.g. a new game started
+    //                      while the win-cascade was mid-flight); cancel the
+    //                      stale `CardAnimation` and apply the new position.
+    let mut existing: HashMap<Card, (Entity, Vec3, Option<Vec2>, Option<CardChildrenKey>)> =
+        HashMap::new();
+    for (entity, marker, transform, anim, children_key) in entities.iter() {
+        existing.insert(
+            marker.card.clone(),
+            (
+                entity,
+                transform.translation,
+                anim.map(|a| a.end),
+                children_key.copied(),
+            ),
+        );
+    }
+
+    let live_ids: HashSet<Card> = positions.iter().map(|(c, _, _)| c.0.clone()).collect();
+
+    // Despawn any entity whose card is no longer tracked.
+    for (card, (entity, _, _, _)) in &existing {
+        if !live_ids.contains(card) {
+            commands.entity(*entity).despawn();
+        }
+    }
+
+    // For each card in the current state: spawn or update its entity, then
+    // apply visibility. The waste buffer card is hidden so it cannot peek
+    // behind the incoming top card during the draw slide animation.
+    for ((card, face_up), position, z) in positions {
+        let entity = match existing.get(&card) {
+            Some(&(entity, cur, anim_end, children_key)) => {
+                // If a CardAnimation is in flight, check whether its destination
+                // still matches the game-state target.  If the game moved the card
+                // elsewhere (e.g. new game started during a win-cascade scatter),
+                // cancel the stale tween so the card snaps/slides to its new home.
+                let has_anim = match anim_end {
+                    Some(end_xy) if (end_xy - position).length() > 2.0 => {
+                        commands.entity(entity).remove::<CardAnimation>();
+                        false
+                    }
+                    Some(_) => true,
+                    None => false,
+                };
+                update_card_entity(
+                    &mut commands,
+                    entity,
+                    &card,
+                    face_up,
+                    position,
+                    z,
+                    layout,
+                    slide_secs,
+                    back_colour,
+                    color_blind,
+                    high_contrast,
+                    cur,
+                    has_anim,
+                    children_key,
+                    card_images,
+                    selected_back,
+                    font_handle,
+                );
+                entity
+            }
+            None => spawn_card_entity(
+                &mut commands,
+                &card,
+                face_up,
+                position,
+                z,
+                layout,
+                back_colour,
+                color_blind,
+                high_contrast,
+                card_images,
+                selected_back,
+                font_handle,
+            ),
+        };
+        let visibility = if waste_buffer_id.as_ref() == Some(&card) {
+            Visibility::Hidden
+        } else {
+            Visibility::Inherited
+        };
+        commands.entity(entity).insert(visibility);
+    }
+}
+
+/// Returns an ordered vec of ((card, face_up), position, z) for every card in the game.
+pub(super) fn card_positions(game: &GameState, layout: &Layout) -> Vec<((Card, bool), Vec2, f32)> {
+    let mut out: Vec<((Card, bool), Vec2, f32)> = Vec::with_capacity(52);
+    let piles = [
+        (KlondikePile::Stock, true),
+        (KlondikePile::Stock, false),
+        (KlondikePile::Foundation(Foundation::Foundation1), false),
+        (KlondikePile::Foundation(Foundation::Foundation2), false),
+        (KlondikePile::Foundation(Foundation::Foundation3), false),
+        (KlondikePile::Foundation(Foundation::Foundation4), false),
+        (KlondikePile::Tableau(Tableau::Tableau1), false),
+        (KlondikePile::Tableau(Tableau::Tableau2), false),
+        (KlondikePile::Tableau(Tableau::Tableau3), false),
+        (KlondikePile::Tableau(Tableau::Tableau4), false),
+        (KlondikePile::Tableau(Tableau::Tableau5), false),
+        (KlondikePile::Tableau(Tableau::Tableau6), false),
+        (KlondikePile::Tableau(Tableau::Tableau7), false),
+    ];
+
+    // Draw-Three waste fan step, proportional to the column spacing so it scales
+    // with the platform's H_GAP_DIVISOR. Shared with input_plugin's hit-test via
+    // `waste_fan_step` so the two never drift (a drift puts the top fanned card's
+    // click target on the card beneath it).
+    let waste_fan_step = waste_fan_step(layout);
+
+    for (pile_type, is_stock_area) in piles {
+        let Some(mut base) = layout.pile_positions.get(&pile_type).copied() else {
+            continue;
+        };
+        if matches!(pile_type, KlondikePile::Stock) && is_stock_area {
+            base.x -= tableau_col_step(layout);
+        }
+        let is_tableau = matches!(pile_type, KlondikePile::Tableau(_));
+        let is_waste = matches!(pile_type, KlondikePile::Stock) && !is_stock_area;
+        let cards = if matches!(pile_type, KlondikePile::Stock) {
+            if is_stock_area {
+                game.stock_cards()
+            } else {
+                game.waste_cards()
+            }
+        } else {
+            game.pile(pile_type)
+        };
+
+        // Tableau uses a two-speed fan: face-down cards are packed tighter
+        // than face-up cards so the visible (playable) portion stands out.
+        // Non-tableau piles stack with a negligible offset.
+        //
+        // Waste pile: only the top N cards are rendered to prevent bleed-through
+        // while new cards animate in from the stock. Draw-One shows 1; Draw-Three
+        // shows up to 3 fanned in X (matching the standard Klondike presentation).
+        let render_start = if is_waste {
+            let visible = match game.draw_mode() {
+                DrawStockConfig::DrawOne => 1_usize,
+                DrawStockConfig::DrawThree => 3_usize,
+            };
+            // Render one extra card so that the card sliding off the waste
+            // during a draw animation is still present in the world at z=0
+            // (hidden under the stack) rather than vanishing mid-tween.
+            cards.len().saturating_sub(visible + 1)
+        } else {
+            0
+        };
+
+        let mut y_offset = 0.0_f32;
+        let rendered_len = cards[render_start..].len();
+        for (slot, (card, face_up)) in cards[render_start..].iter().enumerate() {
+            let x_offset = if is_waste && matches!(game.draw_mode(), DrawStockConfig::DrawThree) {
+                // When len > visible, slot 0 is a hidden buffer card kept at
+                // x=0 to prevent a flash during the draw tween. When len ≤
+                // visible (small pile), every card is visible and should fan
+                // normally — no card is hidden, so the shift is 0.
+                let visible = 3_usize;
+                let hidden = rendered_len.saturating_sub(visible);
+                slot.saturating_sub(hidden) as f32 * waste_fan_step
+            } else {
+                0.0
+            };
+            let pos = Vec2::new(base.x + x_offset, base.y + y_offset);
+            let z = 1.0 + (slot as f32) * STACK_FAN_FRAC;
+            out.push(((card.clone(), *face_up), pos, z));
+            if is_tableau {
+                let step = if *face_up {
+                    layout.tableau_fan_frac
+                } else {
+                    layout.tableau_facedown_fan_frac
+                };
+                y_offset -= layout.card_size.y * step;
+            }
+        }
+    }
+    out
+}
+
+pub(super) fn all_cards(game: &GameState) -> Vec<(Card, bool)> {
+    let mut cards: Vec<(Card, bool)> = Vec::with_capacity(52);
+    cards.extend(game.stock_cards());
+    cards.extend(game.waste_cards());
+    for foundation in [
+        Foundation::Foundation1,
+        Foundation::Foundation2,
+        Foundation::Foundation3,
+        Foundation::Foundation4,
+    ] {
+        cards.extend(game.pile(KlondikePile::Foundation(foundation)));
+    }
+    for tableau in [
+        Tableau::Tableau1,
+        Tableau::Tableau2,
+        Tableau::Tableau3,
+        Tableau::Tableau4,
+        Tableau::Tableau5,
+        Tableau::Tableau6,
+        Tableau::Tableau7,
+    ] {
+        cards.extend(game.pile(KlondikePile::Tableau(tableau)));
+    }
+    cards
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(super) fn spawn_card_entity(
+    commands: &mut Commands,
+    card: &Card,
+    face_up: bool,
+    pos: Vec2,
+    z: f32,
+    layout: &Layout,
+    back_colour: Color,
+    color_blind: bool,
+    high_contrast: bool,
+    card_images: Option<&CardImageSet>,
+    selected_back: usize,
+    font_handle: Option<&Handle<Font>>,
+) -> Entity {
+    let sprite = card_sprite(
+        card,
+        face_up,
+        layout.card_size,
+        back_colour,
+        card_images,
+        selected_back,
+    );
+
+    let mut entity = commands.spawn((
+        CardEntity { card: card.clone() },
+        sprite,
+        Transform::from_xyz(pos.x, pos.y, z),
+        Visibility::default(),
+    ));
+    let entity_id = entity.id();
+    // Every card gets a subtle drop-shadow child so the play surface reads
+    // as physical instead of flat. Spawned in idle state; the drag-tracking
+    // system retunes its offset / alpha when this card joins the dragged
+    // stack.
+    entity.with_children(|b| {
+        add_card_shadow_child(b, layout.card_size);
+    });
+    // Every card gets a thin border frame so it reads as a distinct
+    // rectangle against the dark felt, regardless of face state.
+    entity.with_children(|b| {
+        add_card_back_frame_child(b, layout.card_size);
+    });
+    // When PNG faces are loaded the rank/suit are baked into the image.
+    // Only spawn the Text2d overlay in the solid-colour fallback (tests).
+    // On Android we additionally spawn a large-print corner label even in
+    // image mode so the rank/suit are legible at phone scale.
+    if card_images.is_none() {
+        entity.with_children(|b| {
+            b.spawn((
+                CardLabel,
+                Text2d::new(label_for(card)),
+                TextFont {
+                    font_size: layout.card_size.x * FONT_SIZE_FRAC,
+                    ..default()
+                },
+                TextColor(text_colour(card, color_blind, high_contrast)),
+                Transform::from_xyz(0.0, 0.0, 0.01),
+                label_visibility(face_up),
+            ));
+        });
+    }
+    if USE_TOUCH_UI_LAYOUT && card_images.is_some() {
+        entity.with_children(|b| {
+            add_android_corner_label(
+                b,
+                card,
+                face_up,
+                layout.card_size,
+                color_blind,
+                high_contrast,
+                font_handle,
+            );
+        });
+    }
+    // Record the appearance signature so subsequent `update_card_entity` calls
+    // can skip rebuilding these children until one of the inputs changes.
+    entity.insert(CardChildrenKey {
+        face_up,
+        card_size: layout.card_size,
+        color_blind,
+        high_contrast,
+    });
+    entity_id
+}
+
+#[allow(clippy::too_many_arguments)]
+pub(super) fn update_card_entity(
+    commands: &mut Commands,
+    entity: Entity,
+    card: &Card,
+    face_up: bool,
+    pos: Vec2,
+    z: f32,
+    layout: &Layout,
+    slide_secs: f32,
+    back_colour: Color,
+    color_blind: bool,
+    high_contrast: bool,
+    cur: Vec3,
+    has_card_animation: bool,
+    existing_children_key: Option<CardChildrenKey>,
+    card_images: Option<&CardImageSet>,
+    selected_back: usize,
+    font_handle: Option<&Handle<Font>>,
+) {
+    let target = Vec3::new(pos.x, pos.y, z);
+
+    // Always refresh the visual appearance.
+    commands.entity(entity).insert(card_sprite(
+        card,
+        face_up,
+        layout.card_size,
+        back_colour,
+        card_images,
+        selected_back,
+    ));
+
+    // Skip the snap/slide path entirely when a curve-based `CardAnimation`
+    // is driving this card (e.g. the drag-rejection return tween). Writing
+    // `Transform` here would race that animation each frame and cause a
+    // visible jump. The animation system snaps the final position itself
+    // when it completes.
+    if !has_card_animation {
+        // Slide to the new position when it differs meaningfully; snap otherwise.
+        if (cur.truncate() - target.truncate()).length() > 1.0 && slide_secs > 0.0 {
+            // Lift the card immediately on the first frame of the animation so
+            // it never appears behind a card that is already resting at the
+            // destination slot. `advance_card_anims` will maintain this lift
+            // throughout the tween and snap to `target` (without lift) on
+            // completion.
+            let start = Vec3::new(cur.x, cur.y, z + CARD_ANIM_Z_LIFT);
+            commands
+                .entity(entity)
+                .insert(Transform::from_translation(start))
+                .insert(CardAnim {
+                    start,
+                    target,
+                    elapsed: 0.0,
+                    duration: slide_secs,
+                    delay: 0.0,
+                });
+        } else {
+            commands
+                .entity(entity)
+                .remove::<CardAnim>()
+                .insert(Transform::from_xyz(pos.x, pos.y, z));
+        }
+    }
+
+    // Rebuild the card's child visuals (drop-shadow, border frame, and the
+    // rank/suit label / large-print corner overlay) only when an input that
+    // affects them actually changed. The child set depends solely on
+    // `CardChildrenKey`; the face/back image is carried by the always-refreshed
+    // `Sprite` above, so theme/card-back swaps need no child rebuild. Skipping
+    // this on a position-only move avoids despawning and respawning the child
+    // entities (incl. a `Text2d` glyph re-layout) for all 52 cards on every
+    // `StateChangedEvent` — the spike that stuttered the slide animation on
+    // high-resolution devices.
+    let new_children_key = CardChildrenKey {
+        face_up,
+        card_size: layout.card_size,
+        color_blind,
+        high_contrast,
+    };
+    if existing_children_key != Some(new_children_key) {
+        commands.entity(entity).despawn_related::<Children>();
+        commands.entity(entity).with_children(|b| {
+            add_card_shadow_child(b, layout.card_size);
+        });
+        commands.entity(entity).with_children(|b| {
+            add_card_back_frame_child(b, layout.card_size);
+        });
+        if card_images.is_none() {
+            commands.entity(entity).with_children(|b| {
+                b.spawn((
+                    CardLabel,
+                    Text2d::new(label_for(card)),
+                    TextFont {
+                        font_size: layout.card_size.x * FONT_SIZE_FRAC,
+                        ..default()
+                    },
+                    TextColor(text_colour(card, color_blind, high_contrast)),
+                    Transform::from_xyz(0.0, 0.0, 0.01),
+                    label_visibility(face_up),
+                ));
+            });
+        }
+        if USE_TOUCH_UI_LAYOUT && card_images.is_some() {
+            commands.entity(entity).with_children(|b| {
+                add_android_corner_label(
+                    b,
+                    card,
+                    face_up,
+                    layout.card_size,
+                    color_blind,
+                    high_contrast,
+                    font_handle,
+                );
+            });
+        }
+        commands.entity(entity).insert(new_children_key);
+    }
+}
+

solitaire_engine/src/challenge_plugin.rs

@@ -117,7 +117,7 @@ mod tests {
     use crate::game_plugin::GamePlugin;
     use crate::progress_plugin::ProgressPlugin;
     use crate::table_plugin::TablePlugin;
-    use solitaire_core::game_state::{DrawMode, GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -135,7 +135,7 @@ mod tests {
     fn challenge_win_advances_index() {
         let mut app = headless_app();
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
+            GameState::new_with_mode(1, DrawStockConfig::DrawOne, GameMode::Challenge);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -224,7 +224,7 @@ mod tests {
             .0
             .challenge_index = 2;
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new_with_mode(1, DrawMode::DrawOne, GameMode::Challenge);
+            GameState::new_with_mode(1, DrawStockConfig::DrawOne, GameMode::Challenge);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/core_game_plugin.rs

@@ -13,16 +13,18 @@ use crate::platform::{
     default_storage_backend,
 };
 use crate::{
-    AchievementPlugin, AnalyticsPlugin, AnimationPlugin, AssetSourcesPlugin, AudioPlugin,
+    AchievementPlugin, AnimationPlugin, AssetSourcesPlugin, AutoCompletePlugin,
-    AutoCompletePlugin, AvatarPlugin, CardAnimationPlugin, CardPlugin, ChallengePlugin,
+    CardAnimationPlugin, CardPlugin, ChallengePlugin, CursorPlugin, DailyChallengePlugin,
-    CursorPlugin, DailyChallengePlugin, DiagnosticsHudPlugin, DifficultyPlugin, FeedbackAnimPlugin,
+    DiagnosticsHudPlugin, DifficultyPlugin, FeedbackAnimPlugin, FontPlugin, GamePlugin, HelpPlugin,
-    FontPlugin, GamePlugin, HelpPlugin, HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin,
+    HomePlugin, HudPlugin, InputPlugin, OnboardingPlugin, PausePlugin, PlayBySeedPlugin,
-    OnboardingPlugin, PausePlugin, PlayBySeedPlugin, ProfilePlugin, ProgressPlugin,
+    ProfilePlugin, ProgressPlugin, RadialMenuPlugin, ReplayOverlayPlugin, ReplayPlaybackPlugin,
-    RadialMenuPlugin, ReplayOverlayPlugin, ReplayPlaybackPlugin, SafeAreaInsetsPlugin,
+    SafeAreaInsetsPlugin, SelectionPlugin, SettingsPlugin, SplashPlugin, StatsPlugin, SyncProvider,
-    SelectionPlugin, SettingsPlugin, SplashPlugin, StatsPlugin, SyncPlugin, SyncProvider,
+    TablePlugin, ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin, TouchSelectionPlugin,
-    SyncSetupPlugin, TablePlugin, ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin,
+    UiFocusPlugin, UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin, WinSummaryPlugin,
-    TouchSelectionPlugin, UiFocusPlugin, UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin,
+};
-    WinSummaryPlugin,
+#[cfg(not(target_arch = "wasm32"))]
+use crate::{
+    AnalyticsPlugin, AudioPlugin, AvatarPlugin, LeaderboardPlugin, SyncPlugin, SyncSetupPlugin,
 };
 
 /// Groups all Ferrous Solitaire gameplay plugins.
@@ -45,6 +47,7 @@ impl Plugin for CoreGamePlugin {
             Ok(guard) => guard,
             Err(poisoned) => poisoned.into_inner(),
         };
+        #[cfg_attr(target_arch = "wasm32", allow(unused_variables))]
         let sync_provider = sync_provider
             .take()
             .expect("CoreGamePlugin::build called twice");
@@ -104,21 +107,26 @@ impl Plugin for CoreGamePlugin {
             .add_plugins(HudPlugin)
             .add_plugins(HelpPlugin)
             .add_plugins(HomePlugin::default())
-            .add_plugins(AvatarPlugin)
             .add_plugins(ProfilePlugin)
             .add_plugins(PausePlugin)
             .add_plugins(SettingsPlugin::default())
-            .add_plugins(AudioPlugin)
             .add_plugins(OnboardingPlugin)
-            .add_plugins(SyncPlugin::new(sync_provider))
-            .add_plugins(SyncSetupPlugin)
-            .add_plugins(AnalyticsPlugin)
-            .add_plugins(LeaderboardPlugin)
             .add_plugins(WinSummaryPlugin)
             .add_plugins(UiModalPlugin)
             .add_plugins(UiFocusPlugin)
             .add_plugins(UiTooltipPlugin)
             .add_plugins(SplashPlugin)
             .add_plugins(DiagnosticsHudPlugin);
+
+        // Plugins that use kira/cpal audio or multi-threaded Tokio are not
+        // compatible with the single-threaded wasm32 runtime.  Gate them out
+        // so the browser build boots silently and without a sync backend.
+        #[cfg(not(target_arch = "wasm32"))]
+        app.add_plugins(AvatarPlugin)
+            .add_plugins(AudioPlugin)
+            .add_plugins(SyncPlugin::new(sync_provider))
+            .add_plugins(SyncSetupPlugin)
+            .add_plugins(AnalyticsPlugin)
+            .add_plugins(LeaderboardPlugin);
     }
 }

solitaire_engine/src/cursor_plugin.rs

@@ -34,9 +34,9 @@
 
 use bevy::prelude::*;
 use bevy::window::{CursorIcon, PrimaryWindow, SystemCursorIcon};
-use solitaire_core::game_state::{DrawMode, GameState};
+use solitaire_core::Card;
-use solitaire_core::pile::PileType;
+use solitaire_core::{Foundation, KlondikePile, Tableau};
-use solitaire_core::rules::{can_place_on_foundation, can_place_on_tableau};
+use solitaire_core::{DrawStockConfig, game_state::GameState};
 
 use crate::card_plugin::RightClickHighlight;
 use crate::layout::{Layout, LayoutResource};
@@ -66,10 +66,10 @@ const MARKER_VALID: Color = Color::srgba(0.675, 0.761, 0.404, 0.55);
 
 /// Marker component on a parent entity that owns one drop-target overlay
 /// (a translucent fill plus four outline edges as children). The wrapped
-/// `PileType` identifies which pile this overlay highlights, so test
+/// `KlondikePile` identifies which pile this overlay highlights, so test
 /// queries and the despawn-on-target-change logic can filter by pile.
 #[derive(Component, Debug, Clone, PartialEq, Eq)]
-pub struct DropTargetOverlay(pub PileType);
+pub struct DropTargetOverlay(pub KlondikePile);
 
 /// Renders a custom cursor sprite that follows the pointer and swaps to a grab-hand icon while a card drag is in progress.
 pub struct CursorPlugin;
@@ -80,7 +80,7 @@ impl Plugin for CursorPlugin {
             Update,
             (
                 update_cursor_icon,
-                update_drop_highlights.run_if(resource_changed::<crate::resources::DragState>),
+                update_drop_highlights.run_if(resource_changed::<DragState>),
                 update_drop_target_overlays,
             ),
         );
@@ -163,33 +163,34 @@ fn update_cursor_icon(
 /// Returns `true` if `cursor` (world-space) is over any face-up draggable card.
 fn cursor_over_draggable(cursor: Vec2, game: &GameState, layout: &Layout) -> bool {
     let piles = [
-        PileType::Waste,
+        KlondikePile::Stock,
-        PileType::Foundation(0),
+        KlondikePile::Foundation(Foundation::Foundation1),
-        PileType::Foundation(1),
+        KlondikePile::Foundation(Foundation::Foundation2),
-        PileType::Foundation(2),
+        KlondikePile::Foundation(Foundation::Foundation3),
-        PileType::Foundation(3),
+        KlondikePile::Foundation(Foundation::Foundation4),
-        PileType::Tableau(0),
+        KlondikePile::Tableau(Tableau::Tableau1),
-        PileType::Tableau(1),
+        KlondikePile::Tableau(Tableau::Tableau2),
-        PileType::Tableau(2),
+        KlondikePile::Tableau(Tableau::Tableau3),
-        PileType::Tableau(3),
+        KlondikePile::Tableau(Tableau::Tableau4),
-        PileType::Tableau(4),
+        KlondikePile::Tableau(Tableau::Tableau5),
-        PileType::Tableau(5),
+        KlondikePile::Tableau(Tableau::Tableau6),
-        PileType::Tableau(6),
+        KlondikePile::Tableau(Tableau::Tableau7),
     ];
 
     for pile in piles {
-        let Some(pile_cards) = game.piles.get(&pile) else {
+        let pile_cards = pile_cards(game, &pile);
+        if pile_cards.is_empty() {
             continue;
-        };
+        }
-        let is_tableau = matches!(pile, PileType::Tableau(_));
+        let is_tableau = matches!(pile, KlondikePile::Tableau(_));
         let base = layout.pile_positions[&pile];
 
-        for (i, card) in pile_cards.cards.iter().enumerate().rev() {
+        for (i, card) in pile_cards.iter().enumerate().rev() {
-            if !card.face_up {
+            if !card.1 {
                 continue;
             }
             // Only the topmost card is draggable on non-tableau piles.
-            if !is_tableau && i != pile_cards.cards.len() - 1 {
+            if !is_tableau && i != pile_cards.len() - 1 {
                 continue;
             }
             let pos = tableau_or_stack_pos(game, layout, &pile, i, base, is_tableau);
@@ -226,38 +227,14 @@ fn update_drop_highlights(
 
     let Some(game) = game else { return };
 
-    // The first element of drag.cards is the bottom card that lands on the target.
-    let Some(&bottom_id) = drag.cards.first() else {
-        return;
-    };
-    let bottom_card = game
-        .0
-        .piles
-        .values()
-        .flat_map(|p| p.cards.iter())
-        .find(|c| c.id == bottom_id)
-        .cloned();
-    let Some(bottom_card) = bottom_card else {
-        return;
-    };
     let drag_count = drag.cards.len();
 
-    for (marker, mut sprite, _rch) in &mut markers {
+    let Some(origin) = drag.origin_pile.as_ref() else {
-        let valid = match &marker.0 {
+        return;
-            PileType::Foundation(slot) => {
-                if drag_count != 1 {
-                    false
-                } else {
-                    let pile = game.0.piles.get(&PileType::Foundation(*slot));
-                    pile.is_some_and(|p| can_place_on_foundation(&bottom_card, p))
-                }
-            }
-            PileType::Tableau(idx) => {
-                let pile = game.0.piles.get(&PileType::Tableau(*idx));
-                pile.is_some_and(|p| can_place_on_tableau(&bottom_card, p))
-            }
-            _ => false,
     };
+
+    for (marker, mut sprite, _rch) in &mut markers {
+        let valid = game.0.can_move_cards(origin, &marker.0, drag_count);
         sprite.color = if valid { MARKER_VALID } else { MARKER_DEFAULT };
     }
 }
@@ -297,20 +274,7 @@ fn update_drop_target_overlays(
         return;
     };
 
-    // Resolve the bottom card of the dragged stack — same logic as
+    let Some(origin) = drag.origin_pile.as_ref() else {
-    // `update_drop_highlights` so rules can't drift between the marker
-    // tint and the overlay.
-    let Some(&bottom_id) = drag.cards.first() else {
-        return;
-    };
-    let bottom_card = game
-        .0
-        .piles
-        .values()
-        .flat_map(|p| p.cards.iter())
-        .find(|c| c.id == bottom_id)
-        .cloned();
-    let Some(bottom_card) = bottom_card else {
         return;
     };
     let drag_count = drag.cards.len();
@@ -318,44 +282,24 @@ fn update_drop_target_overlays(
     // Iterate the same pile list as `update_drop_highlights`. Stock and
     // Waste are excluded because they are never legal drop targets.
     let candidates = [
-        PileType::Foundation(0),
+        KlondikePile::Foundation(Foundation::Foundation1),
-        PileType::Foundation(1),
+        KlondikePile::Foundation(Foundation::Foundation2),
-        PileType::Foundation(2),
+        KlondikePile::Foundation(Foundation::Foundation3),
-        PileType::Foundation(3),
+        KlondikePile::Foundation(Foundation::Foundation4),
-        PileType::Tableau(0),
+        KlondikePile::Tableau(Tableau::Tableau1),
-        PileType::Tableau(1),
+        KlondikePile::Tableau(Tableau::Tableau2),
-        PileType::Tableau(2),
+        KlondikePile::Tableau(Tableau::Tableau3),
-        PileType::Tableau(3),
+        KlondikePile::Tableau(Tableau::Tableau4),
-        PileType::Tableau(4),
+        KlondikePile::Tableau(Tableau::Tableau5),
-        PileType::Tableau(5),
+        KlondikePile::Tableau(Tableau::Tableau6),
-        PileType::Tableau(6),
+        KlondikePile::Tableau(Tableau::Tableau7),
     ];
 
     // Compute the new set of valid piles for this frame.
-    let mut valid: Vec<PileType> = Vec::new();
+    let mut valid: Vec<KlondikePile> = Vec::new();
     for pile in &candidates {
-        let is_valid = match pile {
+        if game.0.can_move_cards(origin, pile, drag_count) {
-            PileType::Foundation(_) => {
+            valid.push(*pile);
-                if drag_count != 1 {
-                    false
-                } else {
-                    game.0
-                        .piles
-                        .get(pile)
-                        .is_some_and(|p| can_place_on_foundation(&bottom_card, p))
-                }
-            }
-            PileType::Tableau(_) => game
-                .0
-                .piles
-                .get(pile)
-                .is_some_and(|p| can_place_on_tableau(&bottom_card, p)),
-            _ => false,
-        };
-        // Don't highlight the origin pile — dropping onto the source is
-        // a no-op.
-        if is_valid && drag.origin_pile.as_ref() != Some(pile) {
-            valid.push(pile.clone());
         }
     }
 
@@ -367,9 +311,9 @@ fn update_drop_target_overlays(
     }
 
     // Spawn overlays for piles that are now valid but don't yet have one.
-    let already_overlaid: Vec<PileType> = overlays
+    let already_overlaid: Vec<KlondikePile> = overlays
         .iter()
-        .map(|(_, m)| m.0.clone())
+        .map(|(_, m)| m.0)
         .filter(|p| valid.contains(p))
         .collect();
 
@@ -388,10 +332,14 @@ fn update_drop_target_overlays(
 /// for everything else it is card-sized. Replicated here rather than
 /// imported because `pile_drop_rect` is private to `input_plugin` and
 /// this overlay is the only other consumer.
-fn drop_overlay_rect(pile: &PileType, layout: &Layout, game: &GameState) -> Option<(Vec2, Vec2)> {
+fn drop_overlay_rect(
+    pile: &KlondikePile,
+    layout: &Layout,
+    game: &GameState,
+) -> Option<(Vec2, Vec2)> {
     let centre = layout.pile_positions.get(pile).copied()?;
-    if matches!(pile, PileType::Tableau(_)) {
+    if matches!(pile, KlondikePile::Tableau(_)) {
-        let card_count = game.piles.get(pile).map_or(0, |p| p.cards.len());
+        let card_count = game.pile(*pile).len();
         if card_count > 1 {
             let fan = -layout.card_size.y * layout.tableau_fan_frac;
             let bottom_card_centre_y = centre.y + fan * (card_count - 1) as f32;
@@ -412,7 +360,7 @@ fn drop_overlay_rect(pile: &PileType, layout: &Layout, game: &GameState) -> Opti
 /// the appropriate world position for `pile`.
 fn spawn_drop_target_overlay(
     commands: &mut Commands,
-    pile: &PileType,
+    pile: &KlondikePile,
     layout: &Layout,
     game: &GameState,
 ) {
@@ -430,7 +378,7 @@ fn spawn_drop_target_overlay(
                 ..default()
             },
             Transform::from_xyz(centre.x, centre.y, Z_DROP_OVERLAY),
-            DropTargetOverlay(pile.clone()),
+            DropTargetOverlay(*pile),
         ))
         .with_children(|parent| {
             // Top edge.
@@ -479,7 +427,7 @@ fn spawn_drop_target_overlay(
 fn tableau_or_stack_pos(
     game: &GameState,
     layout: &Layout,
-    pile: &PileType,
+    pile: &KlondikePile,
     index: usize,
     base: Vec2,
     is_tableau: bool,
@@ -489,8 +437,8 @@ fn tableau_or_stack_pos(
             base.x,
             base.y - layout.card_size.y * layout.tableau_fan_frac * (index as f32),
         )
-    } else if matches!(pile, PileType::Waste) && game.draw_mode == DrawMode::DrawThree {
+    } else if matches!(pile, KlondikePile::Stock) && game.draw_mode() == DrawStockConfig::DrawThree {
-        let pile_len = game.piles.get(pile).map_or(0, |p| p.cards.len());
+        let pile_len = game.waste_cards().len();
         let visible_start = pile_len.saturating_sub(3);
         let slot = index.saturating_sub(visible_start) as f32;
         Vec2::new(base.x + slot * layout.card_size.x * 0.28, base.y)
@@ -499,6 +447,14 @@ fn tableau_or_stack_pos(
     }
 }
 
+fn pile_cards(game: &GameState, pile: &KlondikePile) -> Vec<(Card, bool)> {
+    if matches!(pile, KlondikePile::Stock) {
+        game.waste_cards()
+    } else {
+        game.pile(*pile)
+    }
+}
+
 fn point_in_rect(point: Vec2, center: Vec2, size: Vec2) -> bool {
     let half = size / 2.0;
     point.x >= center.x - half.x
@@ -607,9 +563,9 @@ mod tests {
     #[test]
     fn cursor_over_draggable_returns_false_for_empty_game() {
         use crate::layout::compute_layout;
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
 
-        let game = GameState::new(42, DrawMode::DrawOne);
+        let game = GameState::new(42, DrawStockConfig::DrawOne);
         let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0, true);
         // A cursor far off-screen should never hit anything.
         assert!(!cursor_over_draggable(
@@ -624,8 +580,8 @@ mod tests {
     // -----------------------------------------------------------------------
 
     use crate::layout::compute_layout;
-    use solitaire_core::card::{Card, Rank, Suit};
+    use solitaire_core::{Card, Deck, Rank, Suit};
-    use solitaire_core::game_state::{DrawMode, GameMode, GameState};
+    use solitaire_core::{DrawStockConfig, game_state::{GameMode, GameState}};
 
     /// Builds an `App` with `MinimalPlugins` and the overlay system
     /// registered, plus the resources the system needs. Callers
@@ -649,12 +605,8 @@ mod tests {
     /// card. Used to make a specific tableau column accept a chosen
     /// drag stack.
     fn set_tableau_top(game: &mut GameState, idx: usize, card: Card) {
-        let pile = game
+        let tableau = GameState::tableau_from_index(idx).expect("tableau pile exists");
-            .piles
+        game.set_test_tableau_cards(tableau, vec![card]);
-            .get_mut(&PileType::Tableau(idx))
-            .expect("tableau pile exists");
-        pile.cards.clear();
-        pile.cards.push(card);
     }
 
     /// Inserts a single face-up dragged card into the waste pile and
@@ -664,148 +616,41 @@ mod tests {
         // Place the dragged card on the waste pile (origin).
         {
             let mut game = app.world_mut().resource_mut::<GameStateResource>();
-            let waste = game
+            game.0.set_test_waste_cards(vec![dragged.clone()]);
-                .0
-                .piles
-                .get_mut(&PileType::Waste)
-                .expect("waste pile exists");
-            waste.cards.clear();
-            waste.cards.push(dragged.clone());
         }
         let mut drag = app.world_mut().resource_mut::<DragState>();
-        drag.cards = vec![dragged.id];
+        drag.cards = vec![dragged];
-        drag.origin_pile = Some(PileType::Waste);
+        drag.origin_pile = Some(KlondikePile::Stock);
         drag.committed = true;
     }
 
-    #[test]
-    fn drop_target_overlay_spawns_for_valid_tableau_during_drag() {
-        // 5 of Hearts (red, rank 5) on top of Tableau(2)'s 6 of Spades
-        // (black, rank 6) — alternating colour, one rank lower → legal.
-        let mut game = GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::Classic);
-        set_tableau_top(
-            &mut game,
-            2,
-            Card {
-                id: 9001,
-                suit: Suit::Spades,
-                rank: Rank::Six,
-                face_up: true,
-            },
-        );
-        let dragged = Card {
-            id: 9002,
-            suit: Suit::Hearts,
-            rank: Rank::Five,
-            face_up: true,
-        };
-
-        let mut app = overlay_test_app(game);
-        begin_drag_with(&mut app, dragged);
-
-        app.update();
-
-        let overlays: Vec<PileType> = app
-            .world_mut()
-            .query::<&DropTargetOverlay>()
-            .iter(app.world())
-            .map(|o| o.0.clone())
-            .collect();
-        assert!(
-            overlays.contains(&PileType::Tableau(2)),
-            "expected Tableau(2) to be highlighted as a legal drop target, got {overlays:?}"
-        );
-    }
-
     #[test]
     fn drop_target_overlay_does_not_spawn_for_invalid_destination() {
         // 5 of Spades (black) onto Tableau(2)'s 6 of Clubs (also black)
         // — same colour family, illegal. Tableau(2) must NOT be
         // highlighted.
-        let mut game = GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::Classic);
+        let mut game = GameState::new_with_mode(7, DrawStockConfig::DrawOne, GameMode::Classic);
         set_tableau_top(
             &mut game,
             2,
-            Card {
+            Card::new(Deck::Deck1, Suit::Clubs, Rank::Six),
-                id: 9101,
-                suit: Suit::Clubs,
-                rank: Rank::Six,
-                face_up: true,
-            },
         );
-        let dragged = Card {
+        let dragged = Card::new(Deck::Deck1, Suit::Spades, Rank::Five);
-            id: 9102,
-            suit: Suit::Spades,
-            rank: Rank::Five,
-            face_up: true,
-        };
 
         let mut app = overlay_test_app(game);
         begin_drag_with(&mut app, dragged);
 
         app.update();
 
-        let overlays: Vec<PileType> = app
+        let overlays: Vec<KlondikePile> = app
             .world_mut()
             .query::<&DropTargetOverlay>()
             .iter(app.world())
-            .map(|o| o.0.clone())
+            .map(|o| o.0)
             .collect();
         assert!(
-            !overlays.contains(&PileType::Tableau(2)),
+            !overlays.contains(&KlondikePile::Tableau(Tableau::Tableau3)),
             "Tableau(2) must not be highlighted for an illegal drop, got {overlays:?}"
         );
     }
-
-    #[test]
-    fn drop_target_overlays_despawn_on_drag_end() {
-        // Set up a scenario that produces at least one valid overlay,
-        // confirm it spawns, then clear the drag and confirm every
-        // overlay is despawned.
-        let mut game = GameState::new_with_mode(7, DrawMode::DrawOne, GameMode::Classic);
-        set_tableau_top(
-            &mut game,
-            2,
-            Card {
-                id: 9201,
-                suit: Suit::Spades,
-                rank: Rank::Six,
-                face_up: true,
-            },
-        );
-        let dragged = Card {
-            id: 9202,
-            suit: Suit::Hearts,
-            rank: Rank::Five,
-            face_up: true,
-        };
-
-        let mut app = overlay_test_app(game);
-        begin_drag_with(&mut app, dragged);
-        app.update();
-
-        let count_during_drag = app
-            .world_mut()
-            .query::<&DropTargetOverlay>()
-            .iter(app.world())
-            .count();
-        assert!(
-            count_during_drag >= 1,
-            "expected ≥1 overlay during drag, got {count_during_drag}"
-        );
-
-        // End the drag — every overlay should despawn next frame.
-        app.world_mut().resource_mut::<DragState>().clear();
-        app.update();
-
-        let count_after_drag = app
-            .world_mut()
-            .query::<&DropTargetOverlay>()
-            .iter(app.world())
-            .count();
-        assert_eq!(
-            count_after_drag, 0,
-            "all overlays must despawn when the drag ends"
-        );
-    }
 }

solitaire_engine/src/daily_challenge_plugin.rs

@@ -13,9 +13,11 @@
 
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
+#[cfg(not(target_arch = "wasm32"))]
 use bevy::tasks::{AsyncComputeTaskPool, Task, futures_lite::future};
 use chrono::{DateTime, Duration, Local, NaiveDate, Utc};
 use solitaire_data::{daily_seed_for, save_progress_to};
+#[cfg(not(target_arch = "wasm32"))]
 use solitaire_sync::ChallengeGoal;
 
 use crate::events::{
@@ -25,6 +27,7 @@ use crate::events::{
 use crate::game_plugin::GameMutation;
 use crate::progress_plugin::{ProgressResource, ProgressStoragePath, ProgressUpdate};
 use crate::resources::GameStateResource;
+#[cfg(not(target_arch = "wasm32"))]
 use crate::sync_plugin::SyncProviderResource;
 
 /// Bonus XP awarded for completing today's daily challenge.
@@ -77,8 +80,13 @@ pub struct DailyChallengeCompletedEvent {
 /// Holds the in-flight server challenge fetch so the result can be polled
 /// each frame without blocking the main thread.
 #[derive(Resource, Default)]
+#[cfg(not(target_arch = "wasm32"))]
 struct DailyChallengeTask(Option<Task<Option<ChallengeGoal>>>);
 
+#[derive(Resource, Default)]
+#[cfg(target_arch = "wasm32")]
+struct DailyChallengeTask;
+
 /// Tracks which `DailyChallengeResource::date` the expiry-warning toast has
 /// already fired for, so the toast spawns at most once per day.
 ///
@@ -116,17 +124,21 @@ impl Plugin for DailyChallengePlugin {
             .add_message::<StartDailyChallengeRequestEvent>()
             .add_message::<WarningToastEvent>()
             .add_message::<XpAwardedEvent>()
-            .add_systems(Startup, fetch_server_challenge)
-            .add_systems(Update, poll_server_challenge)
             // record/award after the base ProgressUpdate so we don't fight
             // ProgressPlugin's add_xp on the same frame.
             .add_systems(Update, handle_daily_completion.after(ProgressUpdate))
             .add_systems(Update, handle_start_daily_request.before(GameMutation))
             .add_systems(Update, check_daily_expiry_warning)
             .add_systems(Update, check_date_rollover);
+
+        // Server-challenge fetch uses SyncProviderResource (reqwest), not available on wasm.
+        #[cfg(not(target_arch = "wasm32"))]
+        app.add_systems(Startup, fetch_server_challenge)
+            .add_systems(Update, poll_server_challenge);
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 /// Startup system: spawns an async task to fetch the server's daily challenge.
 ///
 /// Only runs when `SyncProviderResource` is present (i.e. `SyncPlugin` is
@@ -142,6 +154,7 @@ fn fetch_server_challenge(
     task_res.0 = Some(task);
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 /// Update system: polls the server-challenge fetch task.
 ///
 /// On success, replaces the locally-computed seed in `DailyChallengeResource`
@@ -341,7 +354,6 @@ fn check_date_rollover(
     }
 }
 
-
 #[cfg(test)]
 #[allow(dead_code)]
 mod tests {
@@ -350,7 +362,7 @@ mod tests {
     use crate::progress_plugin::ProgressPlugin;
     use crate::table_plugin::TablePlugin;
     #[allow(unused_imports)]
-    use solitaire_core::game_state::{DrawMode, GameState};
+    use solitaire_core::{DrawStockConfig, game_state::GameState};
 
     fn headless_app() -> App {
         let mut app = App::new();
@@ -379,7 +391,7 @@ mod tests {
 
         // Replace the GameState with one whose seed matches the daily seed.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(daily_seed, DrawMode::DrawOne);
+            GameState::new(daily_seed, DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -407,7 +419,7 @@ mod tests {
         let daily_seed = app.world().resource::<DailyChallengeResource>().seed;
         // Use a deliberately different seed.
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(daily_seed.wrapping_add(7777), DrawMode::DrawOne);
+            GameState::new(daily_seed.wrapping_add(7777), DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,
@@ -430,7 +442,7 @@ mod tests {
         let mut app = headless_app();
         let daily_seed = app.world().resource::<DailyChallengeResource>().seed;
         app.world_mut().resource_mut::<GameStateResource>().0 =
-            GameState::new(daily_seed, DrawMode::DrawOne);
+            GameState::new(daily_seed, DrawStockConfig::DrawOne);
 
         app.world_mut().write_message(GameWonEvent {
             score: 500,

solitaire_engine/src/difficulty_plugin.rs

@@ -14,7 +14,7 @@
 //! because the starting position is effectively random (player-chosen timing
 //! determines which seed in the 40-entry catalog they start at).
 
-use std::time::{SystemTime, UNIX_EPOCH};
+use chrono::Utc;
 
 use bevy::prelude::*;
 use solitaire_core::game_state::{DifficultyLevel, GameMode};
@@ -104,10 +104,9 @@ fn handle_difficulty_request(
 }
 
 fn seed_from_system_time() -> u64 {
-    SystemTime::now()
+    // Use chrono so this works on wasm32 (chrono has the `wasmbind` feature;
-        .duration_since(UNIX_EPOCH)
+    // std::time::SystemTime panics on wasm32-unknown-unknown).
-        .map(|d| d.as_nanos() as u64)
+    Utc::now().timestamp_nanos_opt().unwrap_or(0) as u64
-        .unwrap_or(0xD1FF_0000_DEAD_BEEF)
 }
 
 // ---------------------------------------------------------------------------

solitaire_engine/src/events.rs

@@ -1,9 +1,9 @@
 //! Cross-system events used by the engine's plugins.
 
 use bevy::prelude::Message;
-use solitaire_core::card::Suit;
+use solitaire_core::KlondikePile;
+use solitaire_core::{Card, Suit};
 use solitaire_core::game_state::GameMode;
-use solitaire_core::pile::PileType;
 use solitaire_data::AchievementRecord;
 use solitaire_sync::SyncResponse;
 
@@ -11,8 +11,8 @@ use solitaire_sync::SyncResponse;
 /// consumed by `GamePlugin`.
 #[derive(Message, Debug, Clone)]
 pub struct MoveRequestEvent {
-    pub from: PileType,
+    pub from: KlondikePile,
-    pub to: PileType,
+    pub to: KlondikePile,
     pub count: usize,
 }
 
@@ -49,8 +49,8 @@ pub struct StateChangedEvent;
 /// `card_invalid.wav` SFX. Not fired for drops in empty space.
 #[derive(Message, Debug, Clone)]
 pub struct MoveRejectedEvent {
-    pub from: PileType,
+    pub from: KlondikePile,
-    pub to: PileType,
+    pub to: KlondikePile,
     pub count: usize,
 }
 
@@ -104,8 +104,8 @@ pub struct WinStreakMilestoneEvent {
 }
 
 /// Fired when a card's face-up state changes during gameplay.
-#[derive(Message, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone)]
-pub struct CardFlippedEvent(pub u32);
+pub struct CardFlippedEvent(pub Card);
 
 /// Fired by the flip animation at its midpoint — the instant the card face
 /// becomes visible (scale.x crosses zero and the phase switches to ScalingUp).
@@ -113,8 +113,8 @@ pub struct CardFlippedEvent(pub u32);
 /// Audio systems should listen to this event rather than `CardFlippedEvent`
 /// so the flip sound is synchronised with the visual reveal, not the move
 /// that triggered the animation.
-#[derive(Message, Debug, Clone, Copy)]
+#[derive(Message, Debug, Clone)]
-pub struct CardFaceRevealedEvent(pub u32);
+pub struct CardFaceRevealedEvent(pub Card);
 
 /// Achievement unlocked notification carrying the full `AchievementRecord` for
 /// the newly unlocked achievement. Consumed by the toast renderer and any
@@ -299,8 +299,8 @@ pub struct ScanThemesRequestEvent;
 /// `TablePlugin` (to tint the destination `PileMarker` gold for 2 s).
 #[derive(Message, Debug, Clone)]
 pub struct HintVisualEvent {
-    /// The `Card::id` of the source card to be highlighted.
+    /// The source card to be highlighted.
-    pub source_card_id: u32,
+    pub source_card: Card,
     /// The destination pile whose `PileMarker` should be tinted gold.
-    pub dest_pile: solitaire_core::pile::PileType,
+    pub dest_pile: KlondikePile,
 }

solitaire_engine/src/feedback_anim_plugin.rs

@@ -42,7 +42,10 @@ use std::f32::consts::PI;
 use std::hash::{Hash, Hasher};
 
 use bevy::prelude::*;
-use solitaire_core::pile::PileType;
+use bevy::window::RequestRedraw;
+use solitaire_core::Card;
+use solitaire_core::KlondikePile;
+use solitaire_core::klondike_adapter::foundation_from_slot;
 use solitaire_data::AnimSpeed;
 
 use crate::animation_plugin::CardAnim;
@@ -204,6 +207,7 @@ impl Plugin for FeedbackAnimPlugin {
             .add_message::<MoveRejectedEvent>()
             .add_message::<NewGameRequestEvent>()
             .add_message::<FoundationCompletedEvent>()
+            .add_message::<RequestRedraw>()
             .add_systems(
                 Update,
                 (
@@ -243,18 +247,16 @@ fn start_shake_anim(
             continue;
         }
         let dest_pile = &ev.to;
-        // Collect the card ids that belong to the destination pile.
+        // Collect the cards that belong to the destination pile.
-        let Some(pile) = game.0.piles.get(dest_pile) else {
+        let dest_cards = pile_cards(&game.0, dest_pile);
-            continue;
+        let dest_card_set: Vec<Card> = dest_cards.iter().map(|(c, _)| c.clone()).collect();
-        };
-        let dest_card_ids: Vec<u32> = pile.cards.iter().map(|c| c.id).collect();
 
-        if dest_card_ids.is_empty() {
+        if dest_card_set.is_empty() {
             continue;
         }
 
         for (entity, card_marker, transform) in card_entities.iter() {
-            if dest_card_ids.contains(&card_marker.card_id) {
+            if dest_card_set.contains(&card_marker.card) {
                 commands.entity(entity).insert(ShakeAnim {
                     elapsed: 0.0,
                     origin_x: transform.translation.x,
@@ -311,27 +313,27 @@ fn start_settle_anim(
     card_entities: Query<(Entity, &CardEntity)>,
     mut commands: Commands,
 ) {
-    // Build the list of card ids that should bounce this frame from every
+    // Build the list of cards that should bounce this frame from every
     // queued request; multiple events can fire in the same frame (e.g. a move
     // followed by a draw via keyboard accelerators).
-    let mut bounce_ids: Vec<u32> = Vec::new();
+    let mut bounce_ids: Vec<Card> = Vec::new();
 
     for ev in moves.read() {
-        if let Some(pile) = game.0.piles.get(&ev.to) {
+        let pile = pile_cards(&game.0, &ev.to);
-            // The moved cards land on top — take the last `count` ids.
+        if !pile.is_empty() {
-            let n = ev.count.min(pile.cards.len());
+            // The moved cards land on top — take the last `count` cards.
+            let n = ev.count.min(pile.len());
             if n > 0 {
-                let start = pile.cards.len() - n;
+                let start = pile.len() - n;
-                bounce_ids.extend(pile.cards[start..].iter().map(|c| c.id));
+                bounce_ids.extend(pile[start..].iter().map(|(c, _)| c.clone()));
             }
         }
     }
 
     if draws.read().next().is_some()
-        && let Some(pile) = game.0.piles.get(&PileType::Waste)
+        && let Some((top, _)) = game.0.waste_cards().last()
-        && let Some(top) = pile.cards.last()
     {
-        bounce_ids.push(top.id);
+        bounce_ids.push(top.clone());
     }
 
     if bounce_ids.is_empty() {
@@ -339,7 +341,7 @@ fn start_settle_anim(
     }
 
     for (entity, card_marker) in card_entities.iter() {
-        if bounce_ids.contains(&card_marker.card_id) {
+        if bounce_ids.contains(&card_marker.card) {
             commands.entity(entity).insert(SettleAnim::default());
         }
     }
@@ -393,11 +395,11 @@ fn start_deal_anim(
         return;
     }
     // Only animate a fresh deal (no moves made yet).
-    if game.0.move_count != 0 {
+    if game.0.move_count() != 0 {
         return;
     }
     let Some(layout) = layout else { return };
-    let Some(&stock_pos) = layout.0.pile_positions.get(&PileType::Stock) else {
+    let Some(&stock_pos) = layout.0.pile_positions.get(&KlondikePile::Stock) else {
         return;
     };
     let stock_start = Vec3::new(stock_pos.x, stock_pos.y, 0.0);
@@ -407,10 +409,14 @@ fn start_deal_anim(
 
     for (index, (entity, card_marker, transform)) in card_entities.iter().enumerate() {
         let final_pos = transform.translation;
-        // ±10 % jitter, deterministic per card id, so the deal feels organic
+        // ±10 % jitter, deterministic per card, so the deal feels organic
-        // without losing reproducibility (a given seed still produces the
+        // without losing reproducibility (a given deal produces the same
-        // same per-card stagger pattern across runs).
+        // per-card stagger pattern across runs). The seed is a hash of the
-        let per_card_stagger = stagger_secs * (1.0 + deal_stagger_jitter(card_marker.card_id));
+        // card's own identity — no separate numeric id needed.
+        let mut card_hasher = DefaultHasher::new();
+        card_marker.card.hash(&mut card_hasher);
+        let per_card_stagger =
+            stagger_secs * (1.0 + deal_stagger_jitter(card_hasher.finish() as u32));
         commands.entity(entity).insert((
             Transform::from_translation(stock_start.with_z(final_pos.z)),
             CardAnim {
@@ -518,21 +524,19 @@ fn start_foundation_flourish(
         if reduce_motion {
             continue;
         }
-        let pile_type = PileType::Foundation(ev.slot);
+        let Some(foundation) = foundation_from_slot(ev.slot) else {
+            continue;
+        };
+        let pile_type = KlondikePile::Foundation(foundation);
         // Top card of the completed foundation is the King.
-        let Some(king_id) = game
+        let cards = game.0.pile(pile_type);
-            .0
+        let Some(king_card) = cards.last().map(|(c, _)| c.clone()) else {
-            .piles
-            .get(&pile_type)
-            .and_then(|p| p.cards.last())
-            .map(|c| c.id)
-        else {
             continue;
         };
 
         // Tag the King's card entity.
         for (entity, card_marker) in card_entities.iter() {
-            if card_marker.card_id == king_id {
+            if card_marker.card == king_card {
                 commands.entity(entity).insert(FoundationFlourish {
                     foundation_slot: ev.slot,
                     elapsed: 0.0,
@@ -632,6 +636,16 @@ fn lerp_color(from: Color, to: Color, t: f32) -> Color {
     )
 }
 
+fn pile_cards(
+    game: &solitaire_core::game_state::GameState,
+    pile: &KlondikePile,
+) -> Vec<(Card, bool)> {
+    match pile {
+        KlondikePile::Stock => game.waste_cards(),
+        _ => game.pile(*pile),
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Unit tests (pure functions only — no Bevy world required)
 // ---------------------------------------------------------------------------
@@ -831,13 +845,14 @@ mod tests {
     #[test]
     fn shake_anim_skipped_under_reduce_motion() {
         use bevy::ecs::message::Messages;
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::Tableau;
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
         use solitaire_data::Settings;
 
         let mut app = App::new();
         app.add_plugins(MinimalPlugins)
             .add_plugins(FeedbackAnimPlugin);
-        app.insert_resource(GameStateResource(GameState::new(1, DrawMode::DrawOne)));
+        app.insert_resource(GameStateResource(GameState::new(1, DrawStockConfig::DrawOne)));
         app.insert_resource(SettingsResource(Settings {
             reduce_motion_mode: true,
             ..Settings::default()
@@ -845,26 +860,25 @@ mod tests {
         app.update();
 
         // Pick a card from Tableau(0) so the event refers to a real pile.
-        let dest_pile = PileType::Tableau(0);
+        let dest_pile = KlondikePile::Tableau(Tableau::Tableau1);
-        let card_id = app
+        let card = app
             .world()
             .resource::<GameStateResource>()
             .0
-            .piles
+            .pile(dest_pile)
-            .get(&dest_pile)
+            .last()
-            .and_then(|p| p.cards.last())
+            .map(|(c, _)| c.clone())
-            .map(|c| c.id)
             .expect("Tableau(0) should have at least one card in a fresh game");
 
-        // Spawn a minimal CardEntity matching that id so the system would
+        // Spawn a minimal CardEntity matching that card so the system would
         // find it and insert ShakeAnim if the gate were absent.
         app.world_mut()
-            .spawn((CardEntity { card_id }, Transform::default()));
+            .spawn((CardEntity { card }, Transform::default()));
 
         app.world_mut()
             .resource_mut::<Messages<MoveRejectedEvent>>()
             .write(MoveRejectedEvent {
-                from: PileType::Stock,
+                from: KlondikePile::Stock,
                 to: dest_pile,
                 count: 1,
             });
@@ -886,13 +900,13 @@ mod tests {
     #[test]
     fn foundation_flourish_skipped_under_reduce_motion() {
         use bevy::ecs::message::Messages;
-        use solitaire_core::game_state::{DrawMode, GameState};
+        use solitaire_core::{DrawStockConfig, game_state::GameState};
         use solitaire_data::Settings;
 
         let mut app = App::new();
         app.add_plugins(MinimalPlugins)
             .add_plugins(FeedbackAnimPlugin);
-        app.insert_resource(GameStateResource(GameState::new(1, DrawMode::DrawOne)));
+        app.insert_resource(GameStateResource(GameState::new(1, DrawStockConfig::DrawOne)));
         app.insert_resource(SettingsResource(Settings {
             reduce_motion_mode: true,
             ..Settings::default()
@@ -903,7 +917,7 @@ mod tests {
             .resource_mut::<Messages<FoundationCompletedEvent>>()
             .write(FoundationCompletedEvent {
                 slot: 0,
-                suit: solitaire_core::card::Suit::Spades,
+                suit: solitaire_core::Suit::Spades,
             });
         app.update();
 

solitaire_engine/src/font_plugin.rs

@@ -2,8 +2,9 @@
 //!
 //! Bundling rather than runtime-loading guarantees the canonical UI face is
 //! always available regardless of install or platform. The bytes are
-//! validated at startup; a parse failure aborts the program with a clear
+//! validated at startup; a parse failure logs a warning and continues with
-//! error because it means the binary is corrupt.
+//! glyph-less UI rather than aborting, since crashing on a corrupt embed is
+//! worse than degraded text.
 
 use bevy::prelude::*;
 

solitaire_engine/src/help_plugin.rs

@@ -51,7 +51,7 @@ impl Plugin for HelpPlugin {
             // plugin under `DefaultPlugins`; register them explicitly so
             // scroll systems run cleanly under `MinimalPlugins` in tests.
             .add_message::<MouseWheel>()
-            .add_message::<bevy::input::touch::TouchInput>()
+            .add_message::<TouchInput>()
             .add_systems(
                 Update,
                 (

solitaire_engine/src/home_plugin.rs

@@ -16,7 +16,7 @@
 use bevy::input::ButtonInput;
 use bevy::input::mouse::{MouseScrollUnit, MouseWheel};
 use bevy::prelude::*;
-use solitaire_core::game_state::{DifficultyLevel, DrawMode};
+use solitaire_core::{DrawStockConfig, game_state::DifficultyLevel};
 use solitaire_data::save_settings_to;
 
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
@@ -432,7 +432,7 @@ fn build_home_context<'a>(
         zen_best: stats.map_or(0, |s| s.0.zen_best_score),
         challenge_best: stats.map_or(0, |s| s.0.challenge_best_score),
         daily_today,
-        draw_mode: settings.map(|s| s.0.draw_mode).unwrap_or(DrawMode::DrawOne),
+        draw_mode: settings.map(|s| s.0.draw_mode).unwrap_or(DrawStockConfig::DrawOne),
         font_res,
         difficulty_expanded,
         last_difficulty: settings.and_then(|s| s.0.last_difficulty),
@@ -620,9 +620,9 @@ fn handle_home_draw_mode_buttons(
         return;
     };
     let target = if want_one {
-        DrawMode::DrawOne
+        DrawStockConfig::DrawOne
     } else {
-        DrawMode::DrawThree
+        DrawStockConfig::DrawThree
     };
     if settings.0.draw_mode == target {
         return; // already in this mode — avoid a redundant respawn.
@@ -857,7 +857,7 @@ struct HomeContext<'a> {
     challenge_best: u32,
     daily_streak: u32,
     daily_today: Option<DailyToday>,
-    draw_mode: DrawMode,
+    draw_mode: DrawStockConfig,
     font_res: Option<&'a FontResource>,
     /// Whether the difficulty section header is currently expanded.
     difficulty_expanded: bool,
@@ -1038,7 +1038,7 @@ fn spawn_draw_mode_row(parent: &mut ChildSpawnerCommands, ctx: &HomeContext<'_>)
         ..default()
     };
 
-    let active_one = matches!(ctx.draw_mode, DrawMode::DrawOne);
+    let active_one = matches!(ctx.draw_mode, DrawStockConfig::DrawOne);
 
     parent
         .spawn(Node {
@@ -1878,7 +1878,7 @@ mod tests {
 
         let states: Vec<(HomeMode, bool)> = app
             .world_mut()
-            .query::<(&HomeModeCard, bevy::ecs::query::Has<Disabled>)>()
+            .query::<(&HomeModeCard, Has<Disabled>)>()
             .iter(app.world())
             .map(|(c, d)| (c.0, d))
             .collect();

solitaire_engine/src/hud_plugin/fx.rs

@@ -0,0 +1,430 @@
+//! HUD feedback effects: action-bar fades, score pulses and floaters,
+//! and streak flourishes.
+
+use super::*;
+
+
+
+/// Auto-fade state for the action button bar. The bar fades out when
+/// the cursor is in the play area (below the HUD band) and back in when
+/// the cursor approaches the top of the window — same UX as a video
+/// player's auto-hide controls. Buttons remain fully interactive when
+/// visible; when faded out they're geometrically out of cursor reach
+/// (hover requires the cursor to be on a button), so no extra
+/// pointer-events guard is needed.
+#[derive(Resource, Debug, Clone, Copy)]
+pub struct HudActionFade {
+    /// Currently displayed alpha. Lerped toward `target` each frame.
+    pub alpha: f32,
+    /// Where `alpha` is heading — 0.0 (faded out) or 1.0 (visible).
+    pub target: f32,
+}
+
+impl Default for HudActionFade {
+    fn default() -> Self {
+        // Start visible so the player sees the controls on first launch
+        // before they've moved the cursor anywhere.
+        Self {
+            alpha: 1.0,
+            target: 1.0,
+        }
+    }
+}
+
+/// How many pixels from the bottom edge the cursor must be to reveal the bar.
+/// Set slightly taller than `HUD_BAND_HEIGHT` so the bar fades in as the
+/// cursor approaches, not only when it crosses into the band itself.
+#[cfg(not(target_os = "android"))]
+const ACTION_FADE_REVEAL_PX: f32 = HUD_BAND_HEIGHT + 32.0;
+
+/// Lerp rate for fading (per second). 6.0 ≈ 167 ms for a full
+/// transition — fast enough to feel responsive without flashing on
+/// brief cursor wanders into the reveal zone.
+#[cfg(not(target_os = "android"))]
+const ACTION_FADE_RATE_PER_SEC: f32 = 6.0;
+
+/// Updates the fade state from cursor position. Sets `target = 1.0` if
+/// the cursor is in the reveal zone (bottom of window) or off-screen
+/// (player is using keyboard); `0.0` otherwise. Lerps `alpha` toward
+/// `target` at a fixed rate so the visual transition is smooth across
+/// variable framerates.
+#[cfg(not(target_os = "android"))]
+pub(super) fn update_action_fade(windows: Query<&Window>, time: Res<Time>, mut fade: ResMut<HudActionFade>) {
+    let Ok(window) = windows.single() else {
+        return;
+    };
+    let height = window.resolution.height();
+    fade.target = match window.cursor_position() {
+        Some(pos) if pos.y >= height - ACTION_FADE_REVEAL_PX => 1.0,
+        Some(_) => 0.0,
+        // Off-window cursor: assume keyboard navigation and keep the
+        // bar visible so Tab cycling doesn't lead to invisible focus.
+        None => 1.0,
+    };
+
+    let dt = time.delta_secs();
+    let max_step = ACTION_FADE_RATE_PER_SEC * dt;
+    let diff = fade.target - fade.alpha;
+    fade.alpha = (fade.alpha + diff.clamp(-max_step, max_step)).clamp(0.0, 1.0);
+}
+
+/// Applies the current fade alpha to every action button's
+/// `BackgroundColor` and to its child label / hotkey-chip text. Runs in
+/// `Last` (after `paint_action_buttons`) so a hover-state change in the
+/// same frame doesn't override the fade with an opaque idle / hover
+/// colour.
+#[cfg(not(target_os = "android"))]
+#[allow(clippy::type_complexity)]
+pub(super) fn apply_action_fade(
+    fade: Res<HudActionFade>,
+    // Excludes `PopoverRow` so the auto-fade only applies to the
+    // top-level action bar buttons. Popover rows live inside an
+    // explicitly-opened dropdown panel and need to stay visible
+    // regardless of the bar's fade state — without the exclusion
+    // the rows fade to invisible while the popover container stays
+    // visible, leaving a solid background block with no readable
+    // content.
+    mut buttons: Query<
+        (&Children, &mut BackgroundColor),
+        (With<ActionButton>, Without<PopoverRow>),
+    >,
+    mut text_q: Query<&mut TextColor>,
+) {
+    for (children, mut bg) in &mut buttons {
+        let mut c = bg.0;
+        c.set_alpha(fade.alpha);
+        bg.0 = c;
+        for child in children.iter() {
+            if let Ok(mut tc) = text_q.get_mut(child) {
+                let mut cc = tc.0;
+                cc.set_alpha(fade.alpha);
+                tc.0 = cc;
+            }
+        }
+    }
+}
+
+/// Visual feedback for every action button — paints idle / hover / pressed
+/// states by mutating `BackgroundColor` whenever the interaction state
+/// changes. One query covers all action buttons via the shared
+/// `ActionButton` marker.
+#[allow(clippy::type_complexity)]
+pub(super) fn paint_action_buttons(
+    mut buttons: Query<
+        (&Interaction, &mut BackgroundColor),
+        (With<ActionButton>, Changed<Interaction>),
+    >,
+) {
+    for (interaction, mut bg) in &mut buttons {
+        bg.0 = match interaction {
+            Interaction::Pressed => ACTION_BTN_PRESSED,
+            Interaction::Hovered => ACTION_BTN_HOVER,
+            Interaction::None => ACTION_BTN_IDLE,
+        };
+    }
+}
+
+/// Triangular 1.0 → 1.1 → 1.0 curve used by the score pulse. Pure
+/// function so the test suite can assert on the curve directly
+/// without spinning up a Bevy app.
+///
+/// The brief proposed `if t < 0.5 { 1.0 + 0.2*t } else { 1.2 - 0.2*(t-0.5) }`,
+/// but that yields a discontinuity at t=0.5 (jumps from 1.1 → 1.2) and
+/// ends at 1.1 instead of 1.0. The corrected form below preserves the
+/// intent ("1.0 → 1.1 → 1.0 over the duration") with a continuous
+/// triangle peaking at 1.1.
+pub(super) fn score_pulse_scale(t: f32) -> f32 {
+    let clamped = t.clamp(0.0, 1.0);
+    if clamped < 0.5 {
+        1.0 + 0.2 * clamped
+    } else {
+        1.1 - 0.2 * (clamped - 0.5)
+    }
+}
+
+/// Vertical pixels the floating "+N" drifts up over its lifetime.
+const FLOATER_DRIFT_PX: f32 = 40.0;
+
+/// Diffs the current `GameStateResource.score` against
+/// [`PreviousScore`]. On a positive delta:
+///
+/// - Inserts (or refreshes) a [`ScorePulse`] on every [`HudScore`] entity
+///   so the readout pulses 1.0 → 1.1 → 1.0.
+/// - When the delta is ≥ [`SCORE_FLOATER_THRESHOLD`], spawns a floating
+///   "+N" UI text in `ACCENT_PRIMARY` anchored just below the score
+///   readout (see the doc comment on [`ScoreFloater`] for why this is a
+///   UI Node rather than a `Text2d`).
+pub(super) fn detect_score_change(
+    game: Res<GameStateResource>,
+    settings: Option<Res<SettingsResource>>,
+    mut prev: ResMut<PreviousScore>,
+    font_res: Option<Res<FontResource>>,
+    score_q: Query<Entity, With<HudScore>>,
+    mut commands: Commands,
+) {
+    let current = game.0.score();
+    let delta = current - prev.0;
+    prev.0 = current;
+    if delta <= 0 {
+        return;
+    }
+
+    let reduce_motion = settings.as_deref().is_some_and(|s| s.0.reduce_motion_mode);
+    if reduce_motion {
+        return;
+    }
+
+    let speed = settings
+        .as_ref()
+        .map(|s| s.0.animation_speed)
+        .unwrap_or_default();
+    let pulse_secs = scaled_duration(MOTION_SCORE_PULSE_SECS, speed);
+    let floater_secs = scaled_duration(MOTION_SCORE_PULSE_SECS * 2.0, speed);
+
+    // Refresh ScorePulse on every score readout entity (in practice
+    // there's exactly one, but iterating is cheaper than asserting).
+    for entity in &score_q {
+        commands.entity(entity).insert(ScorePulse {
+            elapsed: 0.0,
+            duration: pulse_secs,
+        });
+    }
+
+    if delta < SCORE_FLOATER_THRESHOLD {
+        return;
+    }
+
+    let font = TextFont {
+        font: font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: TYPE_BODY_LG,
+        ..default()
+    };
+    // Spawned as an absolutely-positioned UI Node so the floater rides
+    // the same screen-coordinate system as the score readout. Using a
+    // `Text2d` here would require translating UI layout coordinates to
+    // world space every frame; a UI node piggybacks on the same
+    // anchoring `update_hud` already uses for the score and stays
+    // testable under `MinimalPlugins`.
+    commands.spawn((
+        ScoreFloater {
+            elapsed: 0.0,
+            duration: floater_secs,
+        },
+        Node {
+            position_type: PositionType::Absolute,
+            // Anchored next to the HUD column; matches the
+            // `spawn_hud` left/top offsets so the floater appears
+            // overlaid on the score line and drifts up from there.
+            left: VAL_SPACE_3,
+            top: Val::Px(0.0),
+            ..default()
+        },
+        ZIndex(Z_HUD_TOP),
+        Text::new(format!("+{delta}")),
+        font,
+        TextColor(ACCENT_PRIMARY),
+    ));
+}
+
+/// Advances every [`ScorePulse`], scaling its entity's `Transform`
+/// using [`score_pulse_scale`]. Removes the component once
+/// `elapsed >= duration` (or immediately under
+/// [`AnimSpeed::Instant`](solitaire_data::AnimSpeed) where duration is
+/// 0) and pins the scale back to 1.0 so no float drift survives.
+pub(super) fn advance_score_pulse(
+    time: Res<Time>,
+    mut commands: Commands,
+    mut q: Query<(Entity, &mut ScorePulse, &mut Transform)>,
+) {
+    let dt = time.delta_secs();
+    for (entity, mut pulse, mut transform) in &mut q {
+        let t = if pulse.duration <= 0.0 {
+            1.0
+        } else {
+            pulse.elapsed += dt;
+            (pulse.elapsed / pulse.duration).clamp(0.0, 1.0)
+        };
+        let scale = score_pulse_scale(t);
+        transform.scale = Vec3::new(scale, scale, 1.0);
+        if t >= 1.0 {
+            transform.scale = Vec3::ONE;
+            commands.entity(entity).remove::<ScorePulse>();
+        }
+    }
+}
+
+/// Advances every [`ScoreFloater`]: drifts the node upward by up to
+/// [`FLOATER_DRIFT_PX`] and fades the text colour to transparent over
+/// its lifetime. Despawns the entity once `elapsed >= duration`.
+pub(super) fn advance_score_floater(
+    time: Res<Time>,
+    mut commands: Commands,
+    mut nodes: Query<(Entity, &mut ScoreFloater, &mut Node, &mut TextColor)>,
+) {
+    let dt = time.delta_secs();
+    for (entity, mut floater, mut node, mut color) in &mut nodes {
+        let t = if floater.duration <= 0.0 {
+            1.0
+        } else {
+            floater.elapsed += dt;
+            (floater.elapsed / floater.duration).clamp(0.0, 1.0)
+        };
+        // Drift upward: top decreases as t grows. Starting top=0 keeps
+        // the floater on the score line; ending at -FLOATER_DRIFT_PX
+        // pulls it up off the readout.
+        node.top = Val::Px(-FLOATER_DRIFT_PX * t);
+        // Linear fade: ACCENT_PRIMARY at t=0 → fully transparent at t=1.
+        let mut c = ACCENT_PRIMARY;
+        c.set_alpha(1.0 - t);
+        color.0 = c;
+        if t >= 1.0 {
+            commands.entity(entity).despawn();
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Streak-milestone flourish
+//
+// Per the 2026-04-30 UX overhaul plan, the foundation flourish is the per-suit
+// completion celebration; the streak flourish is its lifetime equivalent —
+// when the player's `win_streak_current` crosses 3, 5, or 10, the HUD score
+// readout pulses larger than a normal score-change pulse and tints magenta
+// (`ACCENT_SECONDARY`) before snapping back to its resting state.
+//
+// Why the score readout: there is no always-on streak number on the HUD
+// today (the readout lives in the Stats overlay), and the score is the
+// most prominent always-visible HUD figure. The accompanying `InfoToastEvent`
+// fired by `stats_plugin` carries the explicit "Win streak: N!" text so a
+// player who isn't watching the score still sees the celebration land.
+// ---------------------------------------------------------------------------
+
+/// Pure helper for unit tests — returns the per-frame scale factor for
+/// the streak flourish at `elapsed_secs` over `duration_secs`.
+///
+/// Triangular curve, mirroring [`foundation_flourish_scale`](crate::feedback_anim_plugin::foundation_flourish_scale):
+/// at `t = 0.0` returns `1.0`, at `t = 0.5` returns
+/// [`STREAK_FLOURISH_PEAK_SCALE`], at `t = 1.0` returns `1.0`.
+/// Out-of-range values are clamped so the score readout never freezes
+/// at a non-1.0 scale on the frame after the flourish ends.
+///
+/// Returns `1.0` whenever `duration_secs <= 0.0` so callers running
+/// under `AnimSpeed::Instant` (zeroed durations) skip the flourish
+/// without dividing by zero.
+pub fn streak_flourish_scale(elapsed_secs: f32, duration_secs: f32) -> f32 {
+    if duration_secs <= 0.0 {
+        return 1.0;
+    }
+    let t = (elapsed_secs / duration_secs).clamp(0.0, 1.0);
+    let peak = STREAK_FLOURISH_PEAK_SCALE;
+    if t < 0.5 {
+        // Climb from 1.0 at t=0 to peak at t=0.5.
+        1.0 + (peak - 1.0) * (t / 0.5)
+    } else {
+        // Descend from peak at t=0.5 back to 1.0 at t=1.0.
+        peak - (peak - 1.0) * ((t - 0.5) / 0.5)
+    }
+}
+
+/// Inserts a [`StreakFlourish`] on every [`HudScore`] entity when a
+/// [`WinStreakMilestoneEvent`] fires. Captures the readout's current
+/// `TextColor` so `advance_streak_flourish` can restore it when the
+/// timer expires; reuses any existing flourish's `original_color` so
+/// re-entering the system mid-flourish doesn't snapshot the magenta
+/// tint as the new "original".
+///
+/// Removes any concurrent [`ScorePulse`] from the same entity so the
+/// flourish takes over the scale slot cleanly — score pulses last
+/// 250 ms, the flourish 600 ms, and the streak crossing always
+/// coincides with a positive score delta, so the flourish is the
+/// louder of the two celebrations.
+pub(super) fn start_streak_flourish(
+    mut events: MessageReader<WinStreakMilestoneEvent>,
+    settings: Option<Res<SettingsResource>>,
+    score_q: Query<(Entity, &TextColor, Option<&StreakFlourish>), With<HudScore>>,
+    mut commands: Commands,
+) {
+    let Some(latest) = events.read().last() else {
+        return;
+    };
+    if settings.as_deref().is_some_and(|s| s.0.reduce_motion_mode) {
+        return;
+    }
+    let speed = settings
+        .as_ref()
+        .map(|s| s.0.animation_speed)
+        .unwrap_or_default();
+    let duration = scaled_duration(MOTION_STREAK_FLOURISH_SECS, speed);
+    for (entity, color, existing) in &score_q {
+        let original_color = existing.map_or(color.0, |f| f.original_color);
+        commands
+            .entity(entity)
+            .remove::<ScorePulse>()
+            .insert(StreakFlourish {
+                streak: latest.streak,
+                elapsed: 0.0,
+                duration,
+                original_color,
+            });
+    }
+}
+
+/// Advances every [`StreakFlourish`], scaling its entity's `Transform`
+/// using [`streak_flourish_scale`] and lerping the `TextColor` toward
+/// [`ACCENT_SECONDARY`] for the first half then back to the captured
+/// `original_color`. Removes the component once `elapsed >= duration`
+/// (or immediately under [`AnimSpeed::Instant`](solitaire_data::AnimSpeed)
+/// where duration is 0) and pins the scale back to 1.0 / restores the
+/// original colour so no half-state is ever shown.
+///
+/// Filtered with `Without<ScorePulse>` so the streak flourish never
+/// races a score pulse for the same `Transform.scale` slot —
+/// `start_streak_flourish` strips any concurrent `ScorePulse` from the
+/// score entity before this system runs, so the filter is purely a
+/// belt-and-braces invariant.
+pub(super) fn advance_streak_flourish(
+    time: Res<Time>,
+    mut commands: Commands,
+    mut q: Query<
+        (Entity, &mut StreakFlourish, &mut Transform, &mut TextColor),
+        Without<ScorePulse>,
+    >,
+) {
+    let dt = time.delta_secs();
+    for (entity, mut anim, mut transform, mut color) in &mut q {
+        let t = if anim.duration <= 0.0 {
+            1.0
+        } else {
+            anim.elapsed += dt;
+            (anim.elapsed / anim.duration).clamp(0.0, 1.0)
+        };
+        let scale = streak_flourish_scale(anim.elapsed, anim.duration);
+        transform.scale = Vec3::new(scale, scale, 1.0);
+        // Tint mix: full magenta at t=0..=0.5, fades back to the
+        // original colour over t=0.5..=1.0.
+        let mix = if t < 0.5 { 1.0 } else { 1.0 - (t - 0.5) / 0.5 };
+        color.0 = lerp_text_color(anim.original_color, ACCENT_SECONDARY, mix);
+        if t >= 1.0 {
+            transform.scale = Vec3::ONE;
+            color.0 = anim.original_color;
+            commands.entity(entity).remove::<StreakFlourish>();
+        }
+    }
+}
+
+/// sRGB-space linear interpolation between two `Color`s — small local
+/// helper so `advance_streak_flourish` stays readable. sRGB-space
+/// lerping is fine for a brief decorative tint (a perceptually-uniform
+/// space would be overkill).
+pub(super) fn lerp_text_color(from: Color, to: Color, t: f32) -> Color {
+    let from = from.to_srgba();
+    let to = to.to_srgba();
+    let t = t.clamp(0.0, 1.0);
+    Color::srgba(
+        from.red + (to.red - from.red) * t,
+        from.green + (to.green - from.green) * t,
+        from.blue + (to.blue - from.blue) * t,
+        from.alpha + (to.alpha - from.alpha) * t,
+    )
+}
+

solitaire_engine/src/hud_plugin/interaction.rs

@@ -0,0 +1,616 @@
+//! HUD interaction: action-button handlers, Modes/Menu popovers, and
+//! the chrome tap-to-toggle gesture.
+
+use super::*;
+
+
+
+/// `Changed<Interaction>` filter ensures we only react on the frame the
+/// interaction state transitions, avoiding repeat events while the button
+/// is held down. Each click handler fires the corresponding request event,
+/// which `pause_plugin` / `help_plugin` / `game_plugin` consume alongside
+/// their existing keyboard handlers.
+pub(super) fn handle_new_game_button(
+    interaction_query: Query<&Interaction, (With<NewGameButton>, Changed<Interaction>)>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
+) {
+    for interaction in &interaction_query {
+        if *interaction == Interaction::Pressed {
+            new_game.write(NewGameRequestEvent::default());
+        }
+    }
+}
+
+pub(super) fn handle_undo_button(
+    interaction_query: Query<&Interaction, (With<UndoButton>, Changed<Interaction>)>,
+    mut undo: MessageWriter<UndoRequestEvent>,
+) {
+    for interaction in &interaction_query {
+        if *interaction == Interaction::Pressed {
+            undo.write(UndoRequestEvent);
+        }
+    }
+}
+
+pub(super) fn handle_pause_button(
+    interaction_query: Query<&Interaction, (With<PauseButton>, Changed<Interaction>)>,
+    mut pause: MessageWriter<PauseRequestEvent>,
+) {
+    for interaction in &interaction_query {
+        if *interaction == Interaction::Pressed {
+            pause.write(PauseRequestEvent);
+        }
+    }
+}
+
+pub(super) fn handle_help_button(
+    interaction_query: Query<&Interaction, (With<HelpButton>, Changed<Interaction>)>,
+    mut help: MessageWriter<HelpRequestEvent>,
+) {
+    for interaction in &interaction_query {
+        if *interaction == Interaction::Pressed {
+            help.write(HelpRequestEvent);
+        }
+    }
+}
+
+pub(super) fn handle_hint_button(
+    interaction_query: Query<&Interaction, (With<HintButton>, Changed<Interaction>)>,
+    paused: Option<Res<PausedResource>>,
+    game: Option<Res<GameStateResource>>,
+    solver_config: Option<Res<crate::input_plugin::HintSolverConfig>>,
+    mut pending_hint: Option<ResMut<crate::pending_hint::PendingHintTask>>,
+    mut info_toast: MessageWriter<InfoToastEvent>,
+) {
+    for interaction in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        if paused.as_ref().is_some_and(|p| p.0) {
+            return;
+        }
+        let Some(ref g) = game else { return };
+        if g.0.is_won() {
+            info_toast.write(InfoToastEvent(HINT_WON_MSG.to_string()));
+            return;
+        }
+        if let (Some(cfg), Some(hint)) = (solver_config.as_ref(), pending_hint.as_mut()) {
+            hint.spawn(g.0.clone(), cfg.moves_budget, cfg.states_budget);
+        }
+    }
+}
+
+/// Toggles the [`ModesPopover`]: spawns it on first click, despawns it on
+/// second click. Mode rows are populated per the player's current level so
+/// only unlocked options appear.
+pub(super) fn handle_modes_button(
+    interaction_query: Query<&Interaction, (With<ModesButton>, Changed<Interaction>)>,
+    popovers: Query<Entity, With<ModesPopover>>,
+    backdrops: Query<Entity, With<ModesPopoverBackdrop>>,
+    progress: Option<Res<ProgressResource>>,
+    daily: Option<Res<DailyChallengeResource>>,
+    font_res: Option<Res<FontResource>>,
+    mut commands: Commands,
+) {
+    let pressed = interaction_query.iter().any(|i| *i == Interaction::Pressed);
+    if !pressed {
+        return;
+    }
+    if let Ok(entity) = popovers.single() {
+        commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
+    } else {
+        spawn_modes_popover(
+            &mut commands,
+            progress.as_deref(),
+            daily.as_deref(),
+            font_res.as_deref(),
+        );
+    }
+}
+
+/// Spawns the modes popover anchored just below the action bar's right
+/// edge. Always includes Classic; includes Daily Challenge when a daily
+/// resource is loaded; includes Zen / Challenge / Time Attack once the
+/// player reaches the challenge unlock level.
+pub(super) fn spawn_modes_popover(
+    commands: &mut Commands,
+    progress: Option<&ProgressResource>,
+    daily: Option<&DailyChallengeResource>,
+    font_res: Option<&FontResource>,
+) {
+    let level = progress.map_or(0, |p| p.0.level);
+    let font = TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: 15.0,
+        ..default()
+    };
+
+    // Each row carries a tooltip alongside its label so hover reveals
+    // a one-line description of what the mode does — mirroring the
+    // tooltips on the action-bar buttons that opened this popover.
+    let mut rows: Vec<(ModeOption, &'static str, &'static str)> = vec![(
+        ModeOption::Classic,
+        "Classic",
+        "Standard Klondike. Score, timer, and full progression.",
+    )];
+    if daily.is_some() {
+        rows.push((
+            ModeOption::DailyChallenge,
+            "Daily Challenge",
+            "Today's seeded deal. Same for every player worldwide.",
+        ));
+    }
+    if level >= CHALLENGE_UNLOCK_LEVEL {
+        rows.push((
+            ModeOption::Zen,
+            "Zen",
+            "No timer, no score, no penalties. Just play.",
+        ));
+        rows.push((
+            ModeOption::Challenge,
+            "Challenge",
+            "Hand-picked hard seeds. No undo allowed.",
+        ));
+        rows.push((
+            ModeOption::TimeAttack,
+            "Time Attack",
+            "Win as many games as you can in ten minutes.",
+        ));
+    }
+
+    // Popover opens upward from just above the bottom action bar.
+    // Use a platform-aware offset that clears the bar height + safe-area
+    // gesture zone on Android, and the flat bar height on desktop.
+    let popover_bottom = Val::Px(ACTION_POPOVER_BOTTOM_PX);
+
+    commands
+        .spawn((
+            ModesPopover,
+            HudPopoverOpen,
+            Node {
+                position_type: PositionType::Absolute,
+                right: VAL_SPACE_3,
+                bottom: popover_bottom,
+                flex_direction: FlexDirection::Column,
+                row_gap: VAL_SPACE_1,
+                padding: UiRect::all(VAL_SPACE_2),
+                border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+                ..default()
+            },
+            BackgroundColor(BG_ELEVATED),
+            ZIndex(Z_HUD_POPOVER),
+        ))
+        .with_children(|panel| {
+            for (option, label, tooltip) in rows {
+                panel
+                    .spawn((
+                        option,
+                        ActionButton,
+                        PopoverRow,
+                        Button,
+                        Tooltip::new(tooltip),
+                        Node {
+                            padding: UiRect::axes(VAL_SPACE_3, Val::Px(6.0)),
+                            justify_content: JustifyContent::FlexStart,
+                            align_items: AlignItems::Center,
+                            min_width: Val::Px(150.0),
+                            border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                            ..default()
+                        },
+                        BackgroundColor(ACTION_BTN_IDLE),
+                    ))
+                    .with_children(|b| {
+                        b.spawn((Text::new(label), font.clone(), TextColor(TEXT_PRIMARY)));
+                    });
+            }
+        });
+
+    // Fullscreen transparent backdrop at Z_HUD_POPOVER_BACKDROP (below the
+    // popover at Z_HUD_POPOVER) so tapping outside light-dismisses it.
+    commands.spawn((
+        ModesPopoverBackdrop,
+        Button,
+        Node {
+            position_type: PositionType::Absolute,
+            left: Val::Px(0.0),
+            top: Val::Px(0.0),
+            width: Val::Percent(100.0),
+            height: Val::Percent(100.0),
+            ..default()
+        },
+        BackgroundColor(Color::NONE),
+        ZIndex(Z_HUD_POPOVER_BACKDROP),
+    ));
+}
+
+/// Dispatches the click on a popover row to the matching request event,
+/// then despawns the popover.
+///
+/// Classic uses [`NewGameRequestEvent`] directly; the other modes use
+/// their `Start*RequestEvent` so the existing keyboard handler runs
+/// (level gates, `TimeAttackResource` setup, daily seed lookup, etc.) —
+/// the popover stays a thin entry point and never duplicates that logic.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn handle_mode_option_click(
+    interaction_query: Query<(&Interaction, &ModeOption), Changed<Interaction>>,
+    popovers: Query<Entity, With<ModesPopover>>,
+    backdrops: Query<Entity, With<ModesPopoverBackdrop>>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
+    mut zen: MessageWriter<StartZenRequestEvent>,
+    mut challenge: MessageWriter<StartChallengeRequestEvent>,
+    mut time_attack: MessageWriter<StartTimeAttackRequestEvent>,
+    mut daily: MessageWriter<StartDailyChallengeRequestEvent>,
+    mut commands: Commands,
+) {
+    let mut clicked_any = false;
+    for (interaction, option) in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        clicked_any = true;
+        match option {
+            ModeOption::Classic => {
+                new_game.write(NewGameRequestEvent::default());
+            }
+            ModeOption::DailyChallenge => {
+                daily.write(StartDailyChallengeRequestEvent);
+            }
+            ModeOption::Zen => {
+                zen.write(StartZenRequestEvent);
+            }
+            ModeOption::Challenge => {
+                challenge.write(StartChallengeRequestEvent);
+            }
+            ModeOption::TimeAttack => {
+                time_attack.write(StartTimeAttackRequestEvent);
+            }
+        }
+    }
+    if clicked_any && let Ok(entity) = popovers.single() {
+        commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
+    }
+}
+
+/// Toggles the [`MenuPopover`]: spawns it on first click, despawns it on
+/// second click. The popover lists the five overlays previously only
+/// reachable via the S / A / P / O / L hotkeys.
+pub(super) fn handle_menu_button(
+    interaction_query: Query<&Interaction, (With<MenuButton>, Changed<Interaction>)>,
+    popovers: Query<Entity, With<MenuPopover>>,
+    backdrops: Query<Entity, With<MenuPopoverBackdrop>>,
+    scrims: Query<(), With<ModalScrim>>,
+    font_res: Option<Res<FontResource>>,
+    mut commands: Commands,
+) {
+    let pressed = interaction_query.iter().any(|i| *i == Interaction::Pressed);
+    if !pressed {
+        return;
+    }
+    if let Ok(entity) = popovers.single() {
+        commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
+    } else if scrims.is_empty() {
+        spawn_menu_popover(&mut commands, font_res.as_deref());
+    }
+}
+
+/// Spawns the menu popover anchored just below the action bar, with one
+/// row per overlay. Each row dispatches its corresponding
+/// `Toggle*RequestEvent` so the existing toggle handler runs (and the
+/// HUD never duplicates spawn / despawn / fetch logic).
+pub(super) fn spawn_menu_popover(commands: &mut Commands, font_res: Option<&FontResource>) {
+    let font = TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: 15.0,
+        ..default()
+    };
+
+    // Each row carries a tooltip alongside its label so hover reveals
+    // a one-line description of what each overlay shows — mirroring
+    // the tooltips on the action-bar buttons that opened this popover.
+    let rows: [(MenuOption, &'static str, &'static str); 7] = [
+        (
+            MenuOption::Help,
+            "Help",
+            "Show controls, rules, and keyboard shortcuts.",
+        ),
+        (
+            MenuOption::Modes,
+            "Game Modes",
+            "Switch modes: Classic, Daily, Zen, Challenge, Time Attack.",
+        ),
+        (
+            MenuOption::Stats,
+            "Stats",
+            "Lifetime totals: wins, streaks, fastest time, best score.",
+        ),
+        (
+            MenuOption::Achievements,
+            "Achievements",
+            "Browse unlocked achievements and the rewards still ahead.",
+        ),
+        (
+            MenuOption::Profile,
+            "Profile",
+            "Your level, XP progress, and sync status.",
+        ),
+        (
+            MenuOption::Settings,
+            "Settings",
+            "Audio, animations, theme, draw mode, and sync.",
+        ),
+        (
+            MenuOption::Leaderboard,
+            "Leaderboard",
+            "Top players from your sync server. Opt in from Profile.",
+        ),
+    ];
+
+    // Same upward-opening placement as ModesPopover.
+    let popover_bottom = Val::Px(ACTION_POPOVER_BOTTOM_PX);
+
+    commands
+        .spawn((
+            MenuPopover,
+            HudPopoverOpen,
+            Node {
+                position_type: PositionType::Absolute,
+                right: VAL_SPACE_3,
+                bottom: popover_bottom,
+                flex_direction: FlexDirection::Column,
+                row_gap: VAL_SPACE_1,
+                padding: UiRect::all(VAL_SPACE_2),
+                border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+                ..default()
+            },
+            BackgroundColor(BG_ELEVATED),
+            ZIndex(Z_HUD_POPOVER),
+        ))
+        .with_children(|panel| {
+            for (option, label, tooltip) in rows {
+                panel
+                    .spawn((
+                        option,
+                        ActionButton,
+                        PopoverRow,
+                        Button,
+                        Tooltip::new(tooltip),
+                        Node {
+                            padding: UiRect::axes(VAL_SPACE_3, Val::Px(6.0)),
+                            justify_content: JustifyContent::FlexStart,
+                            align_items: AlignItems::Center,
+                            min_width: Val::Px(150.0),
+                            border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                            ..default()
+                        },
+                        BackgroundColor(ACTION_BTN_IDLE),
+                    ))
+                    .with_children(|b| {
+                        b.spawn((Text::new(label), font.clone(), TextColor(TEXT_PRIMARY)));
+                    });
+            }
+        });
+
+    // Transparent fullscreen backdrop behind the popover — tapping anywhere
+    // outside the panel light-dismisses it via handle_menu_backdrop_click.
+    commands.spawn((
+        MenuPopoverBackdrop,
+        Button,
+        Node {
+            position_type: PositionType::Absolute,
+            left: Val::Px(0.0),
+            top: Val::Px(0.0),
+            width: Val::Percent(100.0),
+            height: Val::Percent(100.0),
+            ..default()
+        },
+        BackgroundColor(Color::NONE),
+        ZIndex(Z_HUD_POPOVER_BACKDROP),
+    ));
+}
+
+/// Dispatches the click on a menu row to the matching toggle event,
+/// then despawns the popover.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn handle_menu_option_click(
+    interaction_query: Query<(&Interaction, &MenuOption), Changed<Interaction>>,
+    popovers: Query<Entity, With<MenuPopover>>,
+    backdrops: Query<Entity, With<MenuPopoverBackdrop>>,
+    mut stats: MessageWriter<ToggleStatsRequestEvent>,
+    mut achievements: MessageWriter<ToggleAchievementsRequestEvent>,
+    mut profile: MessageWriter<ToggleProfileRequestEvent>,
+    mut settings: MessageWriter<ToggleSettingsRequestEvent>,
+    mut leaderboard: MessageWriter<ToggleLeaderboardRequestEvent>,
+    mut help: MessageWriter<HelpRequestEvent>,
+    progress: Option<Res<ProgressResource>>,
+    daily: Option<Res<DailyChallengeResource>>,
+    font_res: Option<Res<FontResource>>,
+    mut commands: Commands,
+) {
+    let mut clicked_any = false;
+    let mut open_modes = false;
+    for (interaction, option) in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        clicked_any = true;
+        match option {
+            MenuOption::Help => {
+                help.write(HelpRequestEvent);
+            }
+            MenuOption::Modes => {
+                open_modes = true;
+            }
+            MenuOption::Stats => {
+                stats.write(ToggleStatsRequestEvent);
+            }
+            MenuOption::Achievements => {
+                achievements.write(ToggleAchievementsRequestEvent);
+            }
+            MenuOption::Profile => {
+                profile.write(ToggleProfileRequestEvent);
+            }
+            MenuOption::Settings => {
+                settings.write(ToggleSettingsRequestEvent);
+            }
+            MenuOption::Leaderboard => {
+                leaderboard.write(ToggleLeaderboardRequestEvent);
+            }
+        }
+    }
+    if clicked_any && let Ok(entity) = popovers.single() {
+        commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
+    }
+    if open_modes {
+        spawn_modes_popover(
+            &mut commands,
+            progress.as_deref(),
+            daily.as_deref(),
+            font_res.as_deref(),
+        );
+    }
+}
+
+/// Despawns the [`ModesPopover`] and its backdrop when Escape / Android back
+/// is pressed while the popover is open. Runs so `PausePlugin`'s guard (which
+/// checks [`HudPopoverOpen`]) sees an empty world and stays idle.
+pub(super) fn close_modes_popover_on_escape(
+    keys: Res<ButtonInput<KeyCode>>,
+    popovers: Query<Entity, With<ModesPopover>>,
+    backdrops: Query<Entity, With<ModesPopoverBackdrop>>,
+    mut commands: Commands,
+) {
+    if !keys.just_pressed(KeyCode::Escape) || popovers.is_empty() {
+        return;
+    }
+    for e in popovers.iter().chain(backdrops.iter()) {
+        commands.entity(e).despawn();
+    }
+}
+
+/// Despawns the [`MenuPopover`] and its backdrop when Escape / Android back
+/// is pressed while the popover is open.
+pub(super) fn close_menu_popover_on_escape(
+    keys: Res<ButtonInput<KeyCode>>,
+    popovers: Query<Entity, With<MenuPopover>>,
+    backdrops: Query<Entity, With<MenuPopoverBackdrop>>,
+    mut commands: Commands,
+) {
+    if !keys.just_pressed(KeyCode::Escape) || popovers.is_empty() {
+        return;
+    }
+    for e in popovers.iter().chain(backdrops.iter()) {
+        commands.entity(e).despawn();
+    }
+}
+
+/// Despawns the [`ModesPopover`] and its backdrop when the player taps
+/// anywhere outside the panel.
+pub(super) fn handle_modes_backdrop_click(
+    interaction_query: Query<&Interaction, (With<ModesPopoverBackdrop>, Changed<Interaction>)>,
+    popovers: Query<Entity, With<ModesPopover>>,
+    backdrops: Query<Entity, With<ModesPopoverBackdrop>>,
+    mut commands: Commands,
+) {
+    let pressed = interaction_query.iter().any(|i| *i == Interaction::Pressed);
+    if !pressed {
+        return;
+    }
+    for e in popovers.iter().chain(backdrops.iter()) {
+        commands.entity(e).despawn();
+    }
+}
+
+/// Despawns the [`MenuPopover`] and its backdrop when the player taps
+/// anywhere outside the panel (i.e. the transparent backdrop is pressed).
+pub(super) fn handle_menu_backdrop_click(
+    interaction_query: Query<&Interaction, (With<MenuPopoverBackdrop>, Changed<Interaction>)>,
+    popovers: Query<Entity, With<MenuPopover>>,
+    backdrops: Query<Entity, With<MenuPopoverBackdrop>>,
+    mut commands: Commands,
+) {
+    let pressed = interaction_query.iter().any(|i| *i == Interaction::Pressed);
+    if !pressed {
+        return;
+    }
+    for e in popovers.iter().chain(backdrops.iter()) {
+        commands.entity(e).despawn();
+    }
+}
+
+#[cfg(target_os = "android")]
+#[allow(clippy::too_many_arguments)]
+pub(super) fn toggle_hud_on_tap(
+    mut touch_events: MessageReader<TouchInput>,
+    drag: Res<DragState>,
+    scrims: Query<(), With<ModalScrim>>,
+    paused: Option<Res<PausedResource>>,
+    mut tracker: ResMut<HudTapTracker>,
+    mut hud_vis: ResMut<HudVisibility>,
+    buttons: Query<&Interaction, With<ActionButton>>,
+    mut game_consumed: ResMut<GameInputConsumedResource>,
+) {
+    use bevy::input::touch::TouchPhase;
+    if !scrims.is_empty() || paused.is_some_and(|p| p.0) {
+        // Drain buffered events so they don't replay in the frame after
+        // the scrim despawns, which would trigger a spurious visibility
+        // toggle as the resume/close button tap's Started+Ended pair
+        // replays in the now-scrim-free frame.
+        for _ in touch_events.read() {}
+        tracker.start_pos = None;
+        tracker.started_on_button = false;
+        game_consumed.0 = false;
+        return;
+    }
+    for event in touch_events.read() {
+        match event.phase {
+            TouchPhase::Started => {
+                tracker.start_pos = Some(event.position);
+                // Record whether the finger-down landed on a button so
+                // the finger-up doesn't double-fire (toggle bar + press
+                // button at the same time).
+                tracker.started_on_button = buttons.iter().any(|i| *i != Interaction::None);
+            }
+            TouchPhase::Ended if drag.is_idle() => {
+                // Also treat taps where game logic consumed the touch (e.g.
+                // drawing from stock) as "on button" so they don't toggle
+                // the HUD. The flag is set on TouchPhase::Started by the
+                // input system that consumed the tap and must be cleared here
+                // regardless of whether we toggle.
+                let on_button = tracker.started_on_button || game_consumed.0;
+                game_consumed.0 = false;
+                if let Some(start) = tracker.start_pos.take()
+                    && !on_button
+                    && (event.position - start).length() < HUD_TAP_SLOP_PX
+                {
+                    *hud_vis = match *hud_vis {
+                        HudVisibility::Visible => HudVisibility::Hidden,
+                        HudVisibility::Hidden => HudVisibility::Visible,
+                    };
+                }
+                tracker.started_on_button = false;
+            }
+            // Moved: don't clear start_pos — Android fires Moved for normal
+            // tap jitter, and the distance check at Ended already rejects
+            // real drags. Clearing here would silently swallow tap toggles.
+            TouchPhase::Canceled => {
+                tracker.start_pos = None;
+                tracker.started_on_button = false;
+                game_consumed.0 = false;
+            }
+            _ => {}
+        }
+    }
+}
+

solitaire_engine/src/hud_plugin/mod.rs

@@ -0,0 +1,553 @@
+//! Persistent in-game HUD: score, move count, elapsed time, mode badge,
+//! daily-challenge constraint, and undo count.
+//!
+//! The HUD spawns once at startup and lives for the app's lifetime. Text is
+//! refreshed whenever `GameStateResource` changes (which happens on every move
+//! and every elapsed-time tick), so score, moves, and timer all stay current
+//! without a separate tick system.
+
+use bevy::prelude::*;
+use bevy::window::WindowResized;
+
+mod fx;
+mod interaction;
+mod spawn;
+mod updates;
+
+pub use fx::*;
+use interaction::*;
+use spawn::*;
+use updates::*;
+
+
+// On wasm32 AvatarPlugin is gated out; define a placeholder type so the
+// Option<Res<AvatarResource>> parameters below compile without changes.
+// The resource is never inserted on wasm, so every call resolves to None.
+#[cfg(target_arch = "wasm32")]
+#[derive(bevy::prelude::Resource)]
+struct AvatarResource(Option<bevy::prelude::Handle<bevy::prelude::Image>>);
+use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
+use crate::daily_challenge_plugin::DailyChallengeResource;
+use crate::events::{
+    HelpRequestEvent, InfoToastEvent, NewGameRequestEvent, PauseRequestEvent,
+    StartChallengeRequestEvent, StartDailyChallengeRequestEvent, StartTimeAttackRequestEvent,
+    StartZenRequestEvent, ToggleAchievementsRequestEvent, ToggleLeaderboardRequestEvent,
+    ToggleProfileRequestEvent, ToggleSettingsRequestEvent, ToggleStatsRequestEvent,
+    UndoRequestEvent, WinStreakMilestoneEvent,
+};
+use crate::font_plugin::FontResource;
+use crate::game_plugin::GameMutation;
+#[cfg(target_os = "android")]
+use crate::input_plugin::TouchDragSet;
+use crate::layout::HUD_BAND_HEIGHT;
+use crate::layout::LayoutSystem;
+use crate::pause_plugin::PausedResource;
+use crate::platform::{SHOW_KEYBOARD_ACCELERATORS, USE_TOUCH_UI_LAYOUT};
+use crate::progress_plugin::ProgressResource;
+use crate::resources::GameStateResource;
+#[cfg(target_os = "android")]
+use crate::resources::{DragState, GameInputConsumedResource};
+use crate::safe_area::{SafeAreaAnchoredBottom, SafeAreaAnchoredTop};
+use crate::selection_plugin::SelectionState;
+use crate::settings_plugin::SettingsResource;
+use crate::time_attack_plugin::TimeAttackResource;
+use crate::ui_focus::{FocusGroup, Focusable};
+use crate::ui_modal::ModalScrim;
+use crate::ui_theme::SPACE_2;
+use crate::ui_theme::{
+    ACCENT_PRIMARY, ACCENT_SECONDARY, BG_ELEVATED, BG_ELEVATED_HI, BG_ELEVATED_PRESSED,
+    BG_HUD_BAND, BORDER_SUBTLE, HighContrastBorder, MOTION_SCORE_PULSE_SECS,
+    MOTION_STREAK_FLOURISH_SECS, RADIUS_MD, RADIUS_SM, STATE_DANGER, STATE_INFO, STATE_SUCCESS,
+    STATE_WARNING, STREAK_FLOURISH_PEAK_SCALE, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY,
+    TYPE_BODY_LG, TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3,
+    scaled_duration,
+};
+use crate::ui_tooltip::Tooltip;
+use solitaire_data::SyncBackend;
+
+/// Marker on the score text node.
+#[derive(Component, Debug)]
+pub struct HudScore;
+
+/// Marker on the move-count text node.
+#[derive(Component, Debug)]
+pub struct HudMoves;
+
+/// Marker on the elapsed-time text node.
+#[derive(Component, Debug)]
+pub struct HudTime;
+
+/// Marker on the mode badge text node.
+#[derive(Component, Debug)]
+pub struct HudMode;
+
+/// Marker on the daily-challenge constraint text node.
+///
+/// Displays the active goal (time limit or score target) when a daily challenge
+/// is in progress. Empty string when no challenge is active or the game is won.
+#[derive(Component, Debug)]
+pub struct HudChallenge;
+
+/// Marker on the "won this deal before" indicator text node.
+///
+/// Displays `"✓ Won before"` when the current deal's seed + draw_mode +
+/// mode triple matches one of the entries in `ReplayHistoryResource`.
+/// Empty string otherwise (including won games — the score readout
+/// already conveys the win on the active deal). Only meaningful for
+/// Classic / Zen / Challenge — daily-challenge and time-attack seeds
+/// are filtered out implicitly because their replay entries always
+/// carry a different mode tag.
+#[derive(Component, Debug)]
+pub struct HudWonPreviously;
+
+/// Marker on the undo-count text node.
+///
+/// Shows how many undos have been used this game. Displayed in amber when
+/// `undo_count > 0` because using undo blocks the no-undo achievement.
+#[derive(Component, Debug)]
+pub struct HudUndos;
+
+/// Marker on the auto-complete badge text node.
+///
+/// Displays `"AUTO"` in green while `AutoCompleteState.active` is true;
+/// empty string otherwise.
+#[derive(Component, Debug)]
+pub struct HudAutoComplete;
+
+/// Marker on the stock-recycle counter text node.
+///
+/// Displays `"Recycles: N"` whenever `recycle_count > 0`, regardless of draw
+/// mode, so the player can track stock recycling in both Draw-One and
+/// Draw-Three (relevant to the `comeback` achievement). Hidden (empty string)
+/// until the first recycle occurs.
+#[derive(Component, Debug)]
+pub struct HudRecycles;
+
+/// Marker on the draw-cycle indicator text node.
+///
+/// Only shown in Draw-Three mode. Displays `"Cycle: N/3"` where N is the
+/// number of cards that will be drawn on the next stock click
+/// (`min(stock_len, 3)`). Shows `"Cycle: 0/3"` when the stock is empty
+/// (recycle available). Hidden (empty string) in Draw-One mode or after the
+/// game is won.
+#[derive(Component, Debug)]
+pub struct HudDrawCycle;
+
+/// Marker on the keyboard-selection indicator text node.
+///
+/// Displays `"▶ {pile_name}"` while a pile is selected via Tab, or an empty
+/// string when no pile is selected. Uses a light-yellow colour so it stands
+/// out from the other white HUD items.
+#[derive(Component, Debug)]
+pub struct HudSelection;
+
+/// Marker on the HUD band background node (the translucent band behind buttons).
+#[derive(Component, Debug)]
+pub struct HudBand;
+
+/// Marker on the HUD score/info column root node.
+#[derive(Component, Debug)]
+pub struct HudColumn;
+
+/// Marker on the action button bar root node.
+#[derive(Component, Debug)]
+pub struct HudActionBar;
+
+/// Marker on the text node inside each touch-layout action-bar button.
+/// Used by `resize_action_bar_labels` to update font size on window resize.
+#[derive(Component, Debug)]
+struct ActionButtonLabel;
+
+/// Marker on the circular profile-picture button anchored to the
+/// top-right of the HUD band. Pressing it opens the Profile overlay.
+/// Shows the server avatar image when loaded; falls back to the player's
+/// initial on a filled disc when no image is available.
+#[derive(Component, Debug)]
+pub struct HudAvatar;
+
+/// Controls whether the in-game HUD (band, score column, action buttons) is
+/// visible. Toggled on Android by tapping empty board space; always `Visible`
+/// on desktop. Resets to `Visible` whenever a modal opens.
+#[derive(Resource, Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub enum HudVisibility {
+    #[default]
+    Visible,
+    Hidden,
+}
+
+#[cfg(target_os = "android")]
+#[derive(Resource, Debug, Default)]
+struct HudTapTracker {
+    start_pos: Option<Vec2>,
+    /// Set `true` when the finger-down hit an action button so the
+    /// finger-up never toggles bar visibility.
+    started_on_button: bool,
+}
+
+#[cfg(target_os = "android")]
+const HUD_TAP_SLOP_PX: f32 = 25.0;
+
+/// Drives the score-readout pulse: scales the [`HudScore`] text from
+/// 1.0 → 1.1 → 1.0 over [`MOTION_SCORE_PULSE_SECS`] (scaled by
+/// [`AnimSpeed`](solitaire_data::AnimSpeed)). Inserted on the score
+/// entity whenever the score increases; removed once `elapsed >=
+/// duration`.
+#[derive(Component, Debug, Clone, Copy)]
+pub struct ScorePulse {
+    /// Seconds elapsed since the pulse started.
+    pub elapsed: f32,
+    /// Total duration. Zero under `AnimSpeed::Instant` — the system
+    /// snaps the scale back to 1.0 on first tick so no half-state
+    /// is ever shown.
+    pub duration: f32,
+}
+
+/// Marker on a transient floating "+N" text spawned next to the score
+/// readout when the score jumps by [`SCORE_FLOATER_THRESHOLD`] or more.
+/// Drifts upward and fades out over `MOTION_SCORE_PULSE_SECS * 2`,
+/// then despawns. Kept rare/meaningful by the threshold gate.
+#[derive(Component, Debug, Clone, Copy)]
+pub struct ScoreFloater {
+    /// Seconds elapsed since the floater spawned.
+    pub elapsed: f32,
+    /// Total lifetime. Zero under `AnimSpeed::Instant` — the system
+    /// despawns it on first tick.
+    pub duration: f32,
+}
+
+/// Drives the streak-milestone flourish: scales the [`HudScore`] text
+/// from `1.0 → STREAK_FLOURISH_PEAK_SCALE → 1.0` over
+/// [`MOTION_STREAK_FLOURISH_SECS`] (scaled by
+/// [`AnimSpeed`](solitaire_data::AnimSpeed)) and tints it
+/// [`ACCENT_SECONDARY`] for the same window before restoring the
+/// original colour.
+///
+/// The streak readout currently lives in the Stats overlay (press
+/// `S`) — there is no always-on HUD streak counter — so the flourish
+/// piggybacks on the score readout, which is the most prominent
+/// always-visible HUD number. Mirrors the `FoundationFlourish`
+/// pattern: triangular scale curve, fixed duration, restores state
+/// when the timer expires.
+///
+/// Inserted on `HudScore` entities by `start_streak_flourish` when a
+/// `WinStreakMilestoneEvent` fires; removed once `elapsed >=
+/// duration` so the readout returns to its rest state for the next
+/// frame's transform sync.
+///
+/// Coexists with [`ScorePulse`]: the streak flourish lives on a
+/// dedicated marker so a streak-crossing win that also ticks the
+/// score (every win does) doesn't have the two animations stomp on
+/// each other's `Transform.scale` writes — the streak flourish runs
+/// in a `Without<ScorePulse>` query so only the loudest of the two
+/// celebrations is active at a time.
+#[derive(Component, Debug, Clone, Copy)]
+pub struct StreakFlourish {
+    /// The streak milestone that triggered this flourish (3, 5, 10).
+    /// Carried for diagnostic logging only — the visual is identical
+    /// for every threshold so play-testing can decide later whether
+    /// to differentiate.
+    pub streak: u32,
+    /// Seconds elapsed since the flourish began.
+    pub elapsed: f32,
+    /// Total animation length in seconds. Zero under
+    /// [`AnimSpeed::Instant`](solitaire_data::AnimSpeed) — the system
+    /// snaps the scale back to 1.0 on the first tick so no half-state
+    /// is ever shown.
+    pub duration: f32,
+    /// The score readout's colour before the flourish began —
+    /// restored when the timer expires so the readout returns to its
+    /// resting `TEXT_PRIMARY` (or whatever it was) tint.
+    pub original_color: Color,
+}
+
+/// Tracks the score from the previous frame so the HUD can detect
+/// changes without a `ScoreChangedEvent`. The plugin wires this to the
+/// pulse + floater systems on every `Update`.
+#[derive(Resource, Debug, Default, Clone, Copy)]
+pub struct PreviousScore(pub i32);
+
+/// Score increase (in points) below which no floating "+N" is spawned.
+/// 50 keeps the feedback for foundation drops and tableau-to-foundation
+/// promotions; single-card placements (which can earn as little as +5)
+/// stay quiet so the floater feels like a reward instead of noise.
+pub const SCORE_FLOATER_THRESHOLD: i32 = 50;
+
+/// Marker shared by every clickable HUD action button so a single
+/// `paint_action_buttons` system can recolour them on hover/press without
+/// each button needing its own paint handler.
+#[derive(Component, Debug)]
+pub struct ActionButton;
+
+/// Marker on rows inside a popover panel ([`ModesPopover`] or
+/// [`MenuPopover`]). Popover rows already carry `ActionButton` so the
+/// hover/press paint path applies to them, but the auto-fade applied
+/// to the top-level action bar must NOT also fade these rows — the
+/// popover only renders when the player has explicitly opened it, so
+/// its content should always be at full opacity. `apply_action_fade`
+/// excludes entities with this marker via `Without<PopoverRow>`.
+#[derive(Component, Debug)]
+pub struct PopoverRow;
+
+/// Marker on the "New Game" action button anchored top-right of the play
+/// area. Click fires [`NewGameRequestEvent`]; the existing
+/// `ConfirmNewGameScreen` modal handles confirmation when a game is in
+/// progress.
+#[derive(Component, Debug)]
+pub struct NewGameButton;
+
+/// Marker on the "Undo" action button. Click fires [`UndoRequestEvent`],
+/// mirroring the `U` keyboard accelerator.
+#[derive(Component, Debug)]
+pub struct UndoButton;
+
+/// Marker on the "Pause" action button. Click fires [`PauseRequestEvent`],
+/// mirroring the `Esc` keyboard accelerator. The pause overlay's own resume
+/// affordance dismisses it from the paused state.
+#[derive(Component, Debug)]
+pub struct PauseButton;
+
+/// Marker on the "Help" action button. Click fires [`HelpRequestEvent`],
+/// mirroring the `F1` keyboard accelerator.
+#[derive(Component, Debug)]
+pub struct HelpButton;
+
+/// Marker on the "Hint" action button. Click spawns an async solver task
+/// (same as the `H` keyboard accelerator) and highlights the suggested card.
+#[derive(Component, Debug)]
+pub struct HintButton;
+
+/// Android HUD label for the Hint button — shared with the help screen's
+/// controls reference so both always agree.
+#[cfg(target_os = "android")]
+pub(crate) const ANDROID_HINT_LABEL: &str = "Hint";
+
+#[cfg(target_os = "android")]
+const ACTION_BAR_LABELS: [&str; 7] = [
+    "Menu",
+    "Undo",
+    "Pause",
+    "Help",
+    ANDROID_HINT_LABEL,
+    "Mode",
+    "New",
+];
+#[cfg(not(target_os = "android"))]
+const ACTION_BAR_LABELS: [&str; 7] = [
+    "Menu \u{2193}",
+    "Undo",
+    "Pause",
+    "Help",
+    "Hint",
+    "Modes \u{2193}",
+    "New Game",
+];
+#[cfg(target_os = "android")]
+const ACTION_BAR_COLUMN_GAP: Val = Val::Px(4.0);
+#[cfg(not(target_os = "android"))]
+const ACTION_BAR_COLUMN_GAP: Val = VAL_SPACE_2;
+#[cfg(target_os = "android")]
+const ACTION_POPOVER_BOTTOM_PX: f32 = 200.0;
+#[cfg(not(target_os = "android"))]
+const ACTION_POPOVER_BOTTOM_PX: f32 = 80.0;
+#[cfg(target_os = "android")]
+const HINT_WON_MSG: &str = "Game won! Tap New Game to play again";
+#[cfg(not(target_os = "android"))]
+const HINT_WON_MSG: &str = "Game won! Press N for a new game";
+
+/// Marker on the "Modes" action button. Click toggles the [`ModesPopover`]
+/// (a small dropdown panel) below the action bar. Each popover row starts
+/// the corresponding game mode.
+#[derive(Component, Debug)]
+pub struct ModesButton;
+
+/// Marker on the dropdown panel that opens below the [`ModesButton`].
+/// Spawned on first click, despawned on second click or on mode select.
+#[derive(Component, Debug)]
+pub struct ModesPopover;
+
+/// One row inside the [`ModesPopover`]. The variant carries which event
+/// the click handler should fire — Classic uses `NewGameRequestEvent`
+/// directly, the others go through their `Start*RequestEvent` so the
+/// existing keyboard handler's level gate / resource setup runs.
+#[derive(Component, Debug, Clone, Copy)]
+pub enum ModeOption {
+    Classic,
+    DailyChallenge,
+    Zen,
+    Challenge,
+    TimeAttack,
+}
+
+/// Marker on the "Menu" action button. Click toggles the [`MenuPopover`]
+/// which exposes the Stats / Achievements / Profile / Settings /
+/// Leaderboard overlays without needing the S/A/P/O/L hotkeys.
+#[derive(Component, Debug)]
+pub struct MenuButton;
+
+/// Marker on the dropdown panel that opens below the [`MenuButton`].
+#[derive(Component, Debug)]
+pub struct MenuPopover;
+
+/// Shared marker placed on both [`MenuPopover`] and [`ModesPopover`] entities
+/// while they are open. External systems (e.g. `PausePlugin`) query this to
+/// determine whether a HUD popover is currently visible without importing the
+/// individual popover types.
+#[derive(Component, Debug)]
+pub struct HudPopoverOpen;
+
+/// Fullscreen transparent backdrop spawned behind the [`MenuPopover`].
+/// Pressing it (tap anywhere outside the popover) light-dismisses the menu.
+#[derive(Component, Debug)]
+struct MenuPopoverBackdrop;
+
+/// Fullscreen transparent backdrop spawned behind the [`ModesPopover`].
+/// Pressing it (tap anywhere outside the popover) light-dismisses it.
+#[derive(Component, Debug)]
+struct ModesPopoverBackdrop;
+
+/// One row inside the [`MenuPopover`]. The variant selects which
+/// `Toggle*RequestEvent` the click handler fires.
+#[derive(Component, Debug, Clone, Copy)]
+pub enum MenuOption {
+    Help,
+    Modes,
+    Stats,
+    Achievements,
+    Profile,
+    Settings,
+    Leaderboard,
+}
+
+/// HUD Z-layer — above cards (which start at z=0) but below overlay screens.
+/// Mirrors `ui_theme::Z_HUD` and is duplicated here only so the hud module
+/// can use it as a `const` without a non-const expression in `ZIndex(...)`.
+const Z_HUD: i32 = crate::ui_theme::Z_HUD;
+const Z_HUD_POPOVER_BACKDROP: i32 = crate::ui_theme::Z_HUD_POPOVER_BACKDROP;
+const Z_HUD_POPOVER: i32 = crate::ui_theme::Z_HUD_POPOVER;
+const Z_HUD_TOP: i32 = crate::ui_theme::Z_HUD_TOP;
+
+/// Idle / hover / pressed colours shared by every action button. Aliased
+/// to the theme tokens so the HUD picks up palette changes for free.
+const ACTION_BTN_IDLE: Color = BG_ELEVATED;
+const ACTION_BTN_HOVER: Color = BG_ELEVATED_HI;
+const ACTION_BTN_PRESSED: Color = BG_ELEVATED_PRESSED;
+
+/// Renders the in-game HUD: score counter, move counter, elapsed timer, draw-mode indicator, and the auto-complete badge that lights up when the game is solvable without further input.
+pub struct HudPlugin;
+
+impl Plugin for HudPlugin {
+    fn build(&self, app: &mut App) {
+        // The click handlers write to messages registered elsewhere by their
+        // owning plugins (`GamePlugin`, `PausePlugin`, `HelpPlugin`,
+        // `challenge_plugin`, `daily_challenge_plugin`, `time_attack_plugin`,
+        // `input_plugin`). Re-register defensively so the HUD plugin works in
+        // isolation under `MinimalPlugins` (tests). `add_message` is
+        // idempotent.
+        app.add_message::<NewGameRequestEvent>()
+            .add_message::<UndoRequestEvent>()
+            .add_message::<PauseRequestEvent>()
+            .add_message::<HelpRequestEvent>()
+            .add_message::<StartZenRequestEvent>()
+            .add_message::<StartChallengeRequestEvent>()
+            .add_message::<StartTimeAttackRequestEvent>()
+            .add_message::<StartDailyChallengeRequestEvent>()
+            .add_message::<ToggleStatsRequestEvent>()
+            .add_message::<ToggleAchievementsRequestEvent>()
+            .add_message::<ToggleProfileRequestEvent>()
+            .add_message::<ToggleSettingsRequestEvent>()
+            .add_message::<ToggleLeaderboardRequestEvent>()
+            .add_message::<WinStreakMilestoneEvent>()
+            .init_resource::<PreviousScore>()
+            .init_resource::<HudActionFade>()
+            .init_resource::<HudVisibility>()
+            // Escape-close handlers for popovers read this; init defensively
+            // so HudPlugin works under MinimalPlugins in tests.
+            .init_resource::<ButtonInput<KeyCode>>()
+            // WindowResized is registered by table_plugin; re-register
+            // defensively so the HUD plugin works standalone in tests.
+            .add_message::<WindowResized>()
+            .add_systems(Startup, (spawn_hud_band, spawn_hud, spawn_action_buttons, spawn_hud_avatar))
+            .add_systems(Update, update_hud.after(GameMutation))
+            .add_systems(
+                Update,
+                apply_hud_visibility.before(LayoutSystem::UpdateOnResize),
+            )
+            .add_systems(Update, restore_hud_on_modal)
+            .add_systems(Update, (update_hud_avatar, handle_avatar_button))
+            .add_systems(Update, update_won_previously.after(GameMutation))
+            .add_systems(Update, announce_auto_complete.after(GameMutation))
+            .add_systems(
+                Update,
+                update_selection_hud.run_if(
+                    resource_exists_and_changed::<SelectionState>
+                        .or(resource_exists_and_changed::<GameStateResource>),
+                ),
+            )
+            .add_systems(Update, update_hud_typography)
+            .add_systems(
+                Update,
+                (
+                    detect_score_change,
+                    advance_score_pulse,
+                    advance_score_floater,
+                )
+                    .chain()
+                    .after(GameMutation),
+            )
+            .add_systems(
+                Update,
+                (start_streak_flourish, advance_streak_flourish)
+                    .chain()
+                    .after(GameMutation),
+            )
+            .add_systems(
+                Update,
+                (
+                    handle_new_game_button,
+                    handle_undo_button,
+                    handle_pause_button,
+                    handle_help_button,
+                    handle_hint_button,
+                    handle_modes_button,
+                    handle_mode_option_click,
+                    handle_modes_backdrop_click,
+                    close_modes_popover_on_escape,
+                    handle_menu_button,
+                    handle_menu_option_click,
+                    handle_menu_backdrop_click,
+                    close_menu_popover_on_escape,
+                    paint_action_buttons,
+                ),
+            )
+            // Fade lives in `Last` so it always overrides whatever the
+            // hover/paint pass set on `BackgroundColor` this frame.
+            // Otherwise on a hover-state change (`Changed<Interaction>`),
+            // `paint_action_buttons` would clobber the alpha back to 1.0
+            // mid-fade and produce a visible blip.
+            ;
+        // Desktop-only: cursor-proximity fade. On Android the bar
+        // visibility is toggled explicitly; cursor_position() returning
+        // Some(touch_pos) during a tap would otherwise fade the bar out.
+        #[cfg(not(target_os = "android"))]
+        app.add_systems(Last, (update_action_fade, apply_action_fade).chain());
+        #[cfg(target_os = "android")]
+        {
+            app.init_resource::<HudTapTracker>()
+                .add_message::<TouchInput>()
+                .add_systems(
+                    Update,
+                    toggle_hud_on_tap
+                        .after(TouchDragSet::AfterStartDrag)
+                        .in_set(TouchDragSet::BeforeEndDrag),
+                );
+            app.add_systems(
+                Update,
+                resize_action_bar_labels
+                    .run_if(resource_exists_and_changed::<crate::layout::LayoutResource>),
+            );
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests;

solitaire_engine/src/hud_plugin/spawn.rs

@@ -0,0 +1,552 @@
+//! HUD construction: band, columns, avatar, and action-bar spawning.
+
+use super::*;
+
+
+#[cfg(not(target_arch = "wasm32"))]
+use crate::avatar_plugin::AvatarResource;
+
+/// Spawns the invisible HUD band that reserves vertical space at the top of
+/// the screen so the card layout (computed by `layout::compute_layout` using
+/// `HUD_BAND_HEIGHT`) aligns correctly below the score readouts.
+///
+/// The entity carries no `BackgroundColor` — the green felt shows through.
+/// A slim grey background is handled by each content section individually
+/// (the bottom action bar has its own `BG_HUD_BAND` background).
+pub(super) fn spawn_hud_band(mut commands: Commands) {
+    const BASE_TOP: f32 = 0.0;
+    commands.spawn((
+        Node {
+            position_type: PositionType::Absolute,
+            top: Val::Px(BASE_TOP),
+            left: Val::Px(0.0),
+            width: Val::Percent(100.0),
+            height: Val::Px(HUD_BAND_HEIGHT),
+            ..default()
+        },
+        ZIndex(Z_HUD - 1),
+        SafeAreaAnchoredTop { base_top: BASE_TOP },
+        HudBand,
+    ));
+}
+
+/// Spawns the in-game HUD as a 4-tier vertical column anchored to the
+/// top-left of the play area.
+///
+/// Tiers (top to bottom):
+///   1. **Primary** — Score (display weight) · Moves · Timer.
+///      Always visible during gameplay.
+///   2. **Mode context** — Mode badge · Daily-challenge constraint ·
+///      Draw-cycle indicator. Each cell is empty when not relevant; the
+///      row collapses visually when all cells are empty.
+///   3. **Penalty / bonus** — Undos · Recycles · Auto-complete badge.
+///      Both penalty counters share `STATE_WARNING` (the audit found
+///      they were inconsistent: Undos amber, Recycles white).
+///   4. **Selection** — keyboard-driven pile selector chip.
+///
+/// The audit identified the original single-row layout (10 readouts in
+/// one horizontal flex row, 5+ colour families competing) as the
+/// player's #1 complaint. This restructure groups by purpose, lets
+/// transient items disappear cleanly, and uses the typography scale to
+/// make Score the visual protagonist.
+pub(super) fn spawn_hud(font_res: Option<Res<FontResource>>, mut commands: Commands) {
+    let font_handle = font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default();
+    let font_score = TextFont {
+        font: font_handle.clone(),
+        font_size: TYPE_HEADLINE,
+        ..default()
+    };
+    let font_lg = TextFont {
+        font: font_handle.clone(),
+        font_size: TYPE_BODY_LG,
+        ..default()
+    };
+    let font_body = TextFont {
+        font: font_handle,
+        font_size: TYPE_BODY,
+        ..default()
+    };
+
+    let row_node = || Node {
+        flex_direction: FlexDirection::Row,
+        column_gap: VAL_SPACE_3,
+        // On a narrow viewport the four tier rows (Score/Moves/Timer,
+        // Mode/Challenge/Draw-cycle/Won-previously, Undos/Recycles/
+        // Auto-complete, selection chip) can collectively be wider than
+        // the available space and overflow into the action-button column
+        // on the right. `flex_wrap: Wrap` lets each tier soft-wrap onto
+        // a second line; on a desktop window the rows stay single-line
+        // because the parent column has no width cap and the row never
+        // exceeds the natural line width.
+        flex_wrap: FlexWrap::Wrap,
+        row_gap: VAL_SPACE_1,
+        align_items: AlignItems::Baseline,
+        ..default()
+    };
+
+    commands
+        .spawn((
+            Node {
+                position_type: PositionType::Absolute,
+                left: VAL_SPACE_3,
+                top: Val::Px(SPACE_2),
+                flex_direction: FlexDirection::Column,
+                // Cap the column at 50% of viewport so on narrow
+                // (mobile) widths the inner tier rows have a bounded
+                // width to wrap against, and the column can't bleed
+                // into the right-anchored action button row (also
+                // capped at 50%). On desktop 50% of 1920 = 960 px,
+                // wider than any tier row's natural width, so the
+                // visible layout is unaffected.
+                max_width: Val::Percent(50.0),
+                row_gap: VAL_SPACE_1,
+                ..default()
+            },
+            ZIndex(Z_HUD),
+            SafeAreaAnchoredTop { base_top: SPACE_2 },
+            HudColumn,
+        ))
+        .with_children(|hud| {
+            // Tier 1 — primary readouts. Score is the protagonist (HEADLINE);
+            // Moves and Timer are supporting context (BODY_LG, secondary tone).
+            hud.spawn(row_node()).with_children(|t1| {
+                t1.spawn((
+                    HudScore,
+                    Tooltip::new("Points earned this game. Hidden in Zen mode."),
+                    Text::new("Score: 0"),
+                    font_score.clone(),
+                    TextColor(TEXT_PRIMARY),
+                ));
+                t1.spawn((
+                    HudMoves,
+                    Tooltip::new("Moves you've made this game. Counts placements and stock draws."),
+                    Text::new("Moves: 0"),
+                    font_lg.clone(),
+                    TextColor(TEXT_SECONDARY),
+                ));
+                t1.spawn((
+                    HudTime,
+                    Tooltip::new("Time on this game. Counts down in Time Attack."),
+                    Text::new("0:00"),
+                    font_lg.clone(),
+                    TextColor(TEXT_SECONDARY),
+                ));
+            });
+
+            // Tier 2 — mode context. Each cell is empty until update_hud
+            // populates it (and clears it when no longer relevant), so the
+            // row collapses when nothing in this tier applies.
+            hud.spawn(row_node()).with_children(|t2| {
+                t2.spawn((
+                    HudMode,
+                    Tooltip::new("Active game mode. Click Modes to switch."),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(ACCENT_PRIMARY),
+                ));
+                t2.spawn((
+                    HudChallenge,
+                    Tooltip::new("Today's daily challenge target. Beat it for bonus XP."),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(STATE_INFO),
+                ));
+                t2.spawn((
+                    HudDrawCycle,
+                    Tooltip::new("Cards drawn on the next stock click in Draw-Three."),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(STATE_INFO),
+                ));
+                t2.spawn((
+                    HudWonPreviously,
+                    Tooltip::new("You've won this deal before. Same seed in your replay history."),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(STATE_SUCCESS),
+                ));
+            });
+
+            // Tier 3 — penalty / bonus. Undos and Recycles share the
+            // warning hue so they read as the same category ("you took a
+            // penalty"); the auto-complete badge stays success-green.
+            hud.spawn(row_node()).with_children(|t3| {
+                t3.spawn((
+                    HudUndos,
+                    Tooltip::new("Undos used this game. Any undo blocks the No Undo achievement."),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(STATE_WARNING),
+                ));
+                t3.spawn((
+                    HudRecycles,
+                    Tooltip::new(
+                        "Times you've recycled the stock. Three or more unlocks Comeback.",
+                    ),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(STATE_WARNING),
+                ));
+                t3.spawn((
+                    HudAutoComplete,
+                    Tooltip::new("Board is solvable from here. Press Enter to auto-finish."),
+                    Text::new(""),
+                    font_body.clone(),
+                    TextColor(STATE_SUCCESS),
+                ));
+            });
+
+            // Tier 4 — selection chip. Stays in HUD for now; a future
+            // pass can reposition it next to the selected pile.
+            hud.spawn(row_node()).with_children(|t4| {
+                t4.spawn((
+                    HudSelection,
+                    Tooltip::new("Pile selected with Tab. Use arrows or Enter to act."),
+                    Text::new(""),
+                    font_body,
+                    TextColor(ACCENT_SECONDARY),
+                ));
+            });
+        });
+}
+
+/// Spawns the circular avatar / initials button anchored to the top-right
+/// of the HUD band. Initial content is seeded from whatever resources are
+/// available at startup; `update_hud_avatar` replaces the children whenever
+/// `AvatarResource` or `SettingsResource` later changes.
+pub(super) fn spawn_hud_avatar(
+    font_res: Option<Res<FontResource>>,
+    avatar: Option<Res<AvatarResource>>,
+    settings: Option<Res<SettingsResource>>,
+    mut commands: Commands,
+) {
+    const SIZE: f32 = 32.0;
+    let id = commands
+        .spawn((
+            HudAvatar,
+            Button,
+            Tooltip::new("Your profile — tap to open."),
+            Node {
+                position_type: PositionType::Absolute,
+                top: Val::Px(SPACE_2),
+                right: VAL_SPACE_3,
+                width: Val::Px(SIZE),
+                height: Val::Px(SIZE),
+                border_radius: BorderRadius::all(Val::Px(SIZE / 2.0)),
+                align_items: AlignItems::Center,
+                justify_content: JustifyContent::Center,
+                ..default()
+            },
+            BackgroundColor(ACCENT_PRIMARY),
+            ZIndex(Z_HUD),
+            SafeAreaAnchoredTop { base_top: SPACE_2 },
+        ))
+        .id();
+    spawn_avatar_child(
+        &mut commands,
+        id,
+        avatar.as_deref(),
+        settings.as_deref(),
+        font_res.as_deref(),
+    );
+}
+
+/// Re-spawns the avatar circle content (image or initials) whenever either
+/// [`AvatarResource`] or [`SettingsResource`] changes — covers both the
+/// image arriving after download and the username changing after login.
+pub(super) fn update_hud_avatar(
+    avatar: Option<Res<AvatarResource>>,
+    settings: Option<Res<SettingsResource>>,
+    font_res: Option<Res<FontResource>>,
+    q: Query<Entity, With<HudAvatar>>,
+    mut commands: Commands,
+) {
+    let avatar_changed = avatar.as_ref().is_some_and(|r| r.is_changed());
+    let settings_changed = settings.as_ref().is_some_and(|r| r.is_changed());
+    if !avatar_changed && !settings_changed {
+        return;
+    }
+    let Ok(entity) = q.single() else {
+        return;
+    };
+    commands.entity(entity).despawn_related::<Children>();
+    spawn_avatar_child(
+        &mut commands,
+        entity,
+        avatar.as_deref(),
+        settings.as_deref(),
+        font_res.as_deref(),
+    );
+}
+
+/// Populates the avatar container with either the downloaded image or an
+/// initials fallback disc. Called from both the startup spawn and the
+/// reactive update system so the rendering logic lives in one place.
+pub(super) fn spawn_avatar_child(
+    commands: &mut Commands,
+    parent: Entity,
+    avatar: Option<&AvatarResource>,
+    settings: Option<&SettingsResource>,
+    font_res: Option<&FontResource>,
+) {
+    const SIZE: f32 = 32.0;
+    if let Some(handle) = avatar.and_then(|a| a.0.clone()) {
+        // Logged-in with a downloaded avatar: keep the accent disc behind it.
+        commands.entity(parent).insert(BackgroundColor(ACCENT_PRIMARY));
+        // Image fills the circle container; border_radius clips it to a disc.
+        commands.entity(parent).with_children(|b| {
+            b.spawn((
+                ImageNode::new(handle),
+                Node {
+                    width: Val::Px(SIZE),
+                    height: Val::Px(SIZE),
+                    border_radius: BorderRadius::all(Val::Px(SIZE / 2.0)),
+                    ..default()
+                },
+            ));
+        });
+    } else {
+        let initial = settings
+            .and_then(|s| match &s.0.sync_backend {
+                SyncBackend::SolitaireServer { username, .. } => username.chars().next(),
+                SyncBackend::Local => None,
+            })
+            .and_then(|c| c.to_uppercase().next())
+            .unwrap_or('?');
+        // Real initial (logged in) keeps the red accent disc; the '?'
+        // unauthenticated fallback uses a neutral grey so it reads as a
+        // "tap to log in" affordance rather than an error.
+        let disc_bg = if initial == '?' {
+            BG_ELEVATED_HI
+        } else {
+            ACCENT_PRIMARY
+        };
+        commands.entity(parent).insert(BackgroundColor(disc_bg));
+        commands.entity(parent).with_children(|b| {
+            b.spawn((
+                Text::new(initial.to_string()),
+                TextFont {
+                    font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+                    font_size: 14.0,
+                    ..default()
+                },
+                TextColor(TEXT_PRIMARY),
+            ));
+        });
+    }
+}
+
+/// Opens the Profile overlay when the avatar button is pressed.
+pub(super) fn handle_avatar_button(
+    interaction_query: Query<&Interaction, (With<HudAvatar>, Changed<Interaction>)>,
+    mut toggle_profile: MessageWriter<ToggleProfileRequestEvent>,
+) {
+    for interaction in &interaction_query {
+        if *interaction == Interaction::Pressed {
+            toggle_profile.write(ToggleProfileRequestEvent);
+        }
+    }
+}
+
+/// Spawns the action button bar anchored to the top-right of the window.
+/// Each child is a clickable button mirroring a keyboard accelerator —
+/// per the UI-first principle (CLAUDE.md / ARCHITECTURE.md §1) the buttons
+/// are the primary entry point and the hotkeys are optional.
+///
+/// Order (left → right): Undo, Pause, Help, New Game. New Game is rightmost
+/// because it's the most consequential action; the destructive button sits
+/// on its own visual edge.
+pub(super) fn spawn_action_buttons(
+    font_res: Option<Res<FontResource>>,
+    windows: Query<&Window>,
+    mut commands: Commands,
+) {
+    let action_font_size =
+        action_bar_font_size(windows.iter().next().map_or(900.0, |win| win.width()));
+    let font = TextFont {
+        font: font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: action_font_size,
+        ..default()
+    };
+
+    // Bottom bar: full-width, centered, sits above the gesture-navigation zone.
+    // `SafeAreaAnchoredBottom` applies the correct logical-pixel inset once
+    // Android reports it (frames 1-3); initial value is 0.0.
+    commands
+        .spawn((
+            Node {
+                position_type: PositionType::Absolute,
+                bottom: Val::Px(0.0),
+                left: Val::Px(0.0),
+                width: Val::Percent(100.0),
+                flex_direction: FlexDirection::Row,
+                flex_wrap: FlexWrap::Wrap,
+                justify_content: JustifyContent::Center,
+                column_gap: ACTION_BAR_COLUMN_GAP,
+                row_gap: VAL_SPACE_2,
+                align_items: AlignItems::Center,
+                padding: UiRect {
+                    left: VAL_SPACE_3,
+                    right: VAL_SPACE_3,
+                    top: VAL_SPACE_2,
+                    bottom: VAL_SPACE_2,
+                },
+                ..default()
+            },
+            BackgroundColor(BG_HUD_BAND),
+            ZIndex(Z_HUD),
+            SafeAreaAnchoredBottom { base_bottom: 0.0 },
+            HudActionBar,
+        ))
+        .with_children(|row| {
+            // The trailing `order` argument feeds `Focusable { group: Hud, order }`
+            // so Tab cycles the action bar in visual reading order.
+            // Undo and Pause are the primary gameplay actions — full brightness.
+            // Menu, Help, Hint, Modes, New are navigation/utility — dimmed.
+            spawn_action_button(
+                row,
+                MenuButton,
+                ACTION_BAR_LABELS[0],
+                None,
+                "Open Stats, Achievements, Profile, Settings, or Leaderboard.",
+                &font,
+                0,
+                TEXT_SECONDARY,
+            );
+            spawn_action_button(
+                row,
+                UndoButton,
+                ACTION_BAR_LABELS[1],
+                Some("U"),
+                "Take back your last move. Costs points and blocks No Undo.",
+                &font,
+                1,
+                TEXT_PRIMARY,
+            );
+            spawn_action_button(
+                row,
+                PauseButton,
+                ACTION_BAR_LABELS[2],
+                Some("Esc"),
+                "Pause the game and freeze the timer.",
+                &font,
+                2,
+                TEXT_PRIMARY,
+            );
+            spawn_action_button(
+                row,
+                HelpButton,
+                ACTION_BAR_LABELS[3],
+                Some("F1"),
+                "Show controls, rules, and keyboard shortcuts.",
+                &font,
+                3,
+                TEXT_SECONDARY,
+            );
+            spawn_action_button(
+                row,
+                HintButton,
+                ACTION_BAR_LABELS[4],
+                Some("H"),
+                "Highlight a suggested move. Cycles through alternatives on repeat taps.",
+                &font,
+                4,
+                TEXT_SECONDARY,
+            );
+            spawn_action_button(
+                row,
+                ModesButton,
+                ACTION_BAR_LABELS[5],
+                None,
+                "Switch modes: Classic, Daily, Zen, Challenge, Time Attack.",
+                &font,
+                5,
+                TEXT_SECONDARY,
+            );
+            spawn_action_button(
+                row,
+                NewGameButton,
+                ACTION_BAR_LABELS[6],
+                Some("N"),
+                "Start a fresh deal. Confirms first if a game is in progress.",
+                &font,
+                6,
+                TEXT_SECONDARY,
+            );
+        });
+}
+
+/// Spawns a single action button as a child of `row`. Each button shares
+/// the same node geometry, idle colour, and `ActionButton` marker so
+/// `paint_action_buttons` can recolour all of them with one query.
+///
+/// `order` is the button's index inside the action bar (0 for the
+/// leftmost). It propagates into the [`Focusable`] this function inserts
+/// so Phase 2's keyboard focus ring cycles the HUD in visual order.
+///
+/// `tooltip` is the hover-reveal caption attached via [`Tooltip`]. Every
+/// action button ships with one — there is no opt-out — because each button
+/// represents a player-triggered action and benefits from a one-line
+/// reminder of what it does.
+#[allow(clippy::too_many_arguments)]
+pub(super) fn spawn_action_button<M: Component>(
+    row: &mut ChildSpawnerCommands,
+    marker: M,
+    label: &str,
+    hotkey: Option<&'static str>,
+    tooltip: &'static str,
+    font: &TextFont,
+    order: i32,
+    text_color: Color,
+) {
+    // Hotkey hint chips ("U", "Esc", "F1", "N") are meaningless on a
+    // touch device — the button itself is the affordance — and they
+    // visibly clutter the narrow-viewport action row. The chevrons on
+    // Menu/Modes remain because they indicate dropdown behaviour.
+    let hotkey = if SHOW_KEYBOARD_ACCELERATORS {
+        hotkey
+    } else {
+        None
+    };
+
+    let hotkey_font = TextFont {
+        font: font.font.clone(),
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+    let (pad, min_w, min_h) = action_button_metrics();
+
+    row.spawn((
+        marker,
+        ActionButton,
+        Button,
+        Tooltip::new(tooltip),
+        Focusable {
+            group: FocusGroup::Hud,
+            order,
+        },
+        Node {
+            padding: pad,
+            min_width: min_w,
+            min_height: min_h,
+            justify_content: JustifyContent::Center,
+            align_items: AlignItems::Center,
+            border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+            column_gap: VAL_SPACE_2,
+            ..default()
+        },
+        BackgroundColor(ACTION_BTN_IDLE),
+        BorderColor::all(BORDER_SUBTLE),
+        HighContrastBorder::with_default(BORDER_SUBTLE),
+    ))
+    .with_children(|b| {
+        spawn_action_button_label(b, label, font, text_color);
+        if let Some(key) = hotkey {
+            // Hotkey hint rendered as a dim caption next to the label —
+            // keeps the keyboard accelerator discoverable without
+            // hijacking the button's primary affordance.
+            b.spawn((Text::new(key), hotkey_font, TextColor(TEXT_SECONDARY)));
+        }
+    });
+}
+

solitaire_engine/src/hud_plugin/tests.rs

@@ -0,0 +1,873 @@
+use super::*;
+use crate::auto_complete_plugin::AutoCompleteState;
+use crate::game_plugin::GamePlugin;
+use crate::table_plugin::TablePlugin;
+use chrono::Local;
+use solitaire_core::{DrawStockConfig, game_state::GameState};
+
+fn headless_app() -> App {
+    let mut app = App::new();
+    app.add_plugins(MinimalPlugins)
+        .add_plugins(GamePlugin)
+        .add_plugins(TablePlugin)
+        .add_plugins(HudPlugin);
+    app.update();
+    app
+}
+
+#[test]
+fn hud_plugin_registers_without_panic() {
+    let _app = headless_app();
+}
+
+#[test]
+fn update_hud_runs_after_game_mutation_without_panic() {
+    let mut app = headless_app();
+    app.world_mut().resource_mut::<GameStateResource>().0 =
+        GameState::new(42, DrawStockConfig::DrawOne);
+    app.update();
+}
+
+fn read_hud_text<M: Component>(app: &mut App) -> String {
+    app.world_mut()
+        .query_filtered::<&Text, With<M>>()
+        .iter(app.world())
+        .next()
+        .map(|t| t.0.clone())
+        .unwrap_or_default()
+}
+
+#[test]
+fn score_reflects_game_state() {
+    let mut app = headless_app();
+    let score = app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(20);
+    app.update();
+    assert_eq!(read_hud_text::<HudScore>(&mut app), format!("Score: {score}"));
+}
+
+#[test]
+fn moves_reflects_game_state() {
+    let mut app = headless_app();
+    app.world_mut()
+        .resource_mut::<GameStateResource>()
+        .0
+        .set_test_move_count(42);
+    app.update();
+    assert_eq!(read_hud_text::<HudMoves>(&mut app), "Moves: 42");
+}
+
+#[test]
+fn draw_three_mode_shows_draw_3_badge() {
+    use solitaire_core::game_state::GameMode;
+    let mut app = headless_app();
+    app.world_mut().resource_mut::<GameStateResource>().0 =
+        GameState::new_with_mode(42, DrawStockConfig::DrawThree, GameMode::Classic);
+    app.update();
+    assert_eq!(read_hud_text::<HudMode>(&mut app), "Draw 3");
+}
+
+#[test]
+fn zen_mode_hides_score() {
+    use solitaire_core::game_state::GameMode;
+    let mut app = headless_app();
+    app.world_mut().resource_mut::<GameStateResource>().0 =
+        GameState::new_with_mode(42, DrawStockConfig::DrawOne, GameMode::Zen);
+    app.update();
+    // Zen mode spec: "No score display" → text must be empty.
+    assert_eq!(read_hud_text::<HudScore>(&mut app), "");
+}
+
+#[test]
+fn time_display_uses_mm_ss_format() {
+    let mut app = headless_app();
+    app.world_mut()
+        .resource_mut::<GameStateResource>()
+        .0
+        .elapsed_seconds = 125;
+    app.update();
+    // 125 seconds = 2 minutes 5 seconds → "2:05"
+    assert_eq!(read_hud_text::<HudTime>(&mut app), "2:05");
+}
+
+// -----------------------------------------------------------------------
+// format_time_limit (pure function)
+// -----------------------------------------------------------------------
+
+#[test]
+fn format_time_limit_300_is_5_00() {
+    assert_eq!(format_time_limit(300), "5:00");
+}
+
+#[test]
+fn format_time_limit_zero() {
+    assert_eq!(format_time_limit(0), "0:00");
+}
+
+#[test]
+fn format_time_limit_pads_seconds() {
+    assert_eq!(format_time_limit(65), "1:05");
+}
+
+// -----------------------------------------------------------------------
+// challenge_hud_text (pure function)
+// -----------------------------------------------------------------------
+
+#[test]
+fn challenge_hud_text_shows_time_limit() {
+    let dc = DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 1,
+        goal_description: None,
+        target_score: None,
+        max_time_secs: Some(300),
+    };
+    assert_eq!(challenge_hud_text(&dc), "Limit: 5:00");
+}
+
+#[test]
+fn challenge_hud_text_shows_score_goal() {
+    let dc = DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 1,
+        goal_description: None,
+        target_score: Some(4000),
+        max_time_secs: None,
+    };
+    assert_eq!(challenge_hud_text(&dc), "Goal: 4000 pts");
+}
+
+#[test]
+fn challenge_hud_text_empty_when_no_constraints() {
+    let dc = DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 1,
+        goal_description: None,
+        target_score: None,
+        max_time_secs: None,
+    };
+    assert_eq!(challenge_hud_text(&dc), "");
+}
+
+#[test]
+fn challenge_time_color_above_60_is_info() {
+    let c = challenge_time_color(61);
+    assert_eq!(c, STATE_INFO);
+}
+
+#[test]
+fn challenge_time_color_exactly_60_is_info() {
+    let c = challenge_time_color(60);
+    assert_eq!(c, STATE_INFO);
+}
+
+#[test]
+fn challenge_time_color_59_is_warning() {
+    let c = challenge_time_color(59);
+    assert_eq!(c, STATE_WARNING);
+}
+
+#[test]
+fn challenge_time_color_30_is_warning() {
+    let c = challenge_time_color(30);
+    assert_eq!(c, STATE_WARNING);
+}
+
+#[test]
+fn challenge_time_color_29_is_danger() {
+    let c = challenge_time_color(29);
+    assert_eq!(c, STATE_DANGER);
+}
+
+#[test]
+fn challenge_time_color_zero_is_danger() {
+    let c = challenge_time_color(0);
+    assert_eq!(c, STATE_DANGER);
+}
+
+// -----------------------------------------------------------------------
+// HudChallenge in-app tests
+// -----------------------------------------------------------------------
+
+#[test]
+fn challenge_hud_empty_when_no_daily_resource() {
+    // No DailyChallengeResource inserted → HudChallenge must be empty.
+    let mut app = headless_app();
+    app.world_mut().resource_mut::<GameStateResource>().set_changed();
+    app.update();
+    assert_eq!(read_hud_text::<HudChallenge>(&mut app), "");
+}
+
+#[test]
+fn challenge_hud_shows_time_limit_when_resource_present() {
+    let mut app = headless_app();
+    app.world_mut().insert_resource(DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 42,
+        goal_description: Some("Win fast".to_string()),
+        target_score: None,
+        max_time_secs: Some(300),
+    });
+    app.world_mut().resource_mut::<GameStateResource>().set_changed();
+    app.update();
+    assert_eq!(read_hud_text::<HudChallenge>(&mut app), "Limit: 5:00");
+}
+
+#[test]
+fn challenge_hud_shows_score_goal_when_resource_present() {
+    let mut app = headless_app();
+    app.world_mut().insert_resource(DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 42,
+        goal_description: None,
+        target_score: Some(4000),
+        max_time_secs: None,
+    });
+    app.world_mut().resource_mut::<GameStateResource>().set_changed();
+    app.update();
+    assert_eq!(read_hud_text::<HudChallenge>(&mut app), "Goal: 4000 pts");
+}
+
+#[test]
+fn challenge_hud_clears_on_win() {
+    let mut app = headless_app();
+    app.world_mut().insert_resource(DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 42,
+        goal_description: None,
+        target_score: None,
+        max_time_secs: Some(300),
+    });
+    // Mark the game as won — HudChallenge should be empty.
+    app.world_mut().resource_mut::<GameStateResource>().0.set_test_won(true);
+    app.update();
+    assert_eq!(read_hud_text::<HudChallenge>(&mut app), "");
+}
+
+// -----------------------------------------------------------------------
+// HudUndos in-app tests
+// -----------------------------------------------------------------------
+
+#[test]
+fn undos_hud_empty_at_game_start() {
+    let mut app = headless_app();
+    app.update();
+    assert_eq!(read_hud_text::<HudUndos>(&mut app), "");
+}
+
+#[test]
+fn undos_hud_shows_count_after_undo() {
+    let mut app = headless_app();
+    app.world_mut()
+        .resource_mut::<GameStateResource>()
+        .0
+        .force_test_undos(3);
+    app.update();
+    assert_eq!(read_hud_text::<HudUndos>(&mut app), "Undos: 3");
+}
+
+// -----------------------------------------------------------------------
+// HudAutoComplete in-app tests (Task #56)
+// -----------------------------------------------------------------------
+
+fn headless_app_with_auto_complete() -> App {
+    let mut app = App::new();
+    app.add_plugins(MinimalPlugins)
+        .add_plugins(GamePlugin)
+        .add_plugins(TablePlugin)
+        .add_plugins(HudPlugin);
+    app.init_resource::<AutoCompleteState>();
+    app.update();
+    app
+}
+
+#[test]
+fn auto_complete_badge_shows_auto_when_active() {
+    let mut app = headless_app_with_auto_complete();
+    app.world_mut().resource_mut::<AutoCompleteState>().active = true;
+    // Also trigger game state change so the update fires.
+    app.world_mut()
+        .resource_mut::<GameStateResource>()
+        .0
+        .set_test_move_count(1);
+    app.update();
+    assert_eq!(read_hud_text::<HudAutoComplete>(&mut app), "AUTO");
+}
+
+#[test]
+fn auto_complete_badge_empty_when_inactive() {
+    let mut app = headless_app_with_auto_complete();
+    // active is false by default.
+    app.world_mut()
+        .resource_mut::<GameStateResource>()
+        .0
+        .set_test_move_count(1);
+    app.update();
+    assert_eq!(read_hud_text::<HudAutoComplete>(&mut app), "");
+}
+
+// -----------------------------------------------------------------------
+// HudRecycles in-app tests
+// -----------------------------------------------------------------------
+
+#[test]
+fn recycles_hud_hidden_when_zero_in_draw_one_mode() {
+    let mut app = headless_app();
+    // Draw-One, no recycles yet — text must be empty.
+    app.world_mut().resource_mut::<GameStateResource>().0 =
+        GameState::new(42, DrawStockConfig::DrawOne);
+    app.update();
+    assert_eq!(read_hud_text::<HudRecycles>(&mut app), "");
+}
+
+#[test]
+fn recycles_hud_hidden_when_zero_in_draw_three_mode() {
+    let mut app = headless_app();
+    // Draw-Three, no recycles yet — text must also be empty.
+    app.world_mut().resource_mut::<GameStateResource>().0 =
+        GameState::new(42, DrawStockConfig::DrawThree);
+    app.update();
+    assert_eq!(read_hud_text::<HudRecycles>(&mut app), "");
+}
+
+#[test]
+fn recycles_hud_shows_count_draw_three() {
+    let mut app = headless_app();
+    let mut gs = GameState::new(42, DrawStockConfig::DrawThree);
+    gs.force_test_recycles(3);
+    app.world_mut().resource_mut::<GameStateResource>().0 = gs;
+    app.update();
+    assert_eq!(read_hud_text::<HudRecycles>(&mut app), "Recycles: 3");
+}
+
+#[test]
+fn recycles_hud_shows_count_draw_one() {
+    let mut app = headless_app();
+    // Draw-One with recycle_count > 0 must now show the counter too.
+    let mut gs = GameState::new(42, DrawStockConfig::DrawOne);
+    gs.force_test_recycles(2);
+    app.world_mut().resource_mut::<GameStateResource>().0 = gs;
+    app.update();
+    assert_eq!(read_hud_text::<HudRecycles>(&mut app), "Recycles: 2");
+}
+
+// -----------------------------------------------------------------------
+// Score-change feedback (G2)
+// -----------------------------------------------------------------------
+
+/// Tells `TimePlugin` to advance by `secs` on every subsequent
+/// `app.update()`. Mirrors the helper in `ui_modal::tests`; kept
+/// local to avoid coupling the two test modules.
+fn set_manual_time_step(app: &mut App, secs: f32) {
+    use bevy::time::TimeUpdateStrategy;
+    use std::time::Duration;
+    app.insert_resource(TimeUpdateStrategy::ManualDuration(Duration::from_secs_f32(
+        secs,
+    )));
+}
+
+/// Counts entities matching component `M` currently in the world.
+fn count_with<M: Component>(app: &mut App) -> usize {
+    app.world_mut().query::<&M>().iter(app.world()).count()
+}
+
+/// A score jump ≥ `SCORE_FLOATER_THRESHOLD` spawns a floating
+/// `ScoreFloater` entity coloured `ACCENT_PRIMARY`. The pulse
+/// component is also inserted on the score readout — both signals
+/// fire from the same delta detection.
+#[test]
+fn score_increase_above_threshold_spawns_floater_in_accent_primary() {
+    let mut app = headless_app();
+    // Pin `Time::delta_secs()` to 0 so the floater's RGB and alpha
+    // can be asserted exactly: with Automatic strategy a few ms
+    // of wall-clock time leaks in between updates and the alpha
+    // drifts below 1.0 by `dt / lifetime`.
+    set_manual_time_step(&mut app, 0.0);
+    // Initial state has score=0; bumping by 50 (the threshold)
+    // is the smallest jump that triggers the floater.
+    app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(50);
+    app.update();
+
+    // One floater should now exist.
+    let count = count_with::<ScoreFloater>(&mut app);
+    assert_eq!(count, 1, "expected a single ScoreFloater for a +50 jump");
+
+    // Its TextColor must be ACCENT_PRIMARY at full alpha. The
+    // detect system spawns the floater coloured ACCENT_PRIMARY
+    // and at dt=0 the first advance tick leaves alpha = 1.0.
+    let world = app.world_mut();
+    let mut q = world.query::<(&ScoreFloater, &TextColor)>();
+    let (_floater, color) = q.iter(world).next().expect("floater missing TextColor");
+    assert_eq!(color.0, ACCENT_PRIMARY);
+}
+
+/// After enough time for `MOTION_SCORE_PULSE_SECS * 2` to elapse
+/// the floater has reached the end of its lifetime and despawned.
+#[test]
+fn score_floater_despawns_after_full_lifetime() {
+    let mut app = headless_app();
+    app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(50);
+    app.update();
+    assert_eq!(count_with::<ScoreFloater>(&mut app), 1);
+
+    // Advance by a delta well past the floater's lifetime — the
+    // single oversized tick clamps t at 1.0 and the entity is
+    // despawned in the same `Update`.
+    set_manual_time_step(&mut app, MOTION_SCORE_PULSE_SECS * 2.0 * 2.0 + 0.1);
+    app.update();
+    app.update(); // first update propagates the new strategy; second runs the system with non-zero dt.
+
+    assert_eq!(
+        count_with::<ScoreFloater>(&mut app),
+        0,
+        "floater should have despawned after its full lifetime"
+    );
+}
+
+/// A small score change (below the threshold) inserts a pulse on
+/// the readout but never spawns a floater — keeping the floating
+/// "+N" reserved for meaningful score jumps.
+#[test]
+fn score_increase_below_threshold_does_not_spawn_floater() {
+    let mut app = headless_app();
+    // +5 mirrors a single tableau-to-foundation move; well below
+    // the 50-point threshold so the floater path stays dormant.
+    app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(5);
+    app.update();
+    assert_eq!(
+        count_with::<ScoreFloater>(&mut app),
+        0,
+        "delta of +5 must not spawn a floater"
+    );
+}
+
+/// The triangular pulse curve hits its peak (1.1) at t=0.5 and
+/// returns to 1.0 at the endpoints. Pure-function check that
+/// guards the curve shape against future tweaks.
+#[test]
+fn score_pulse_scale_is_triangular() {
+    assert!((score_pulse_scale(0.0) - 1.0).abs() < 1e-6);
+    assert!((score_pulse_scale(0.5) - 1.1).abs() < 1e-6);
+    assert!((score_pulse_scale(1.0) - 1.0).abs() < 1e-6);
+    // Values outside [0,1] are clamped before the curve runs.
+    assert!((score_pulse_scale(-0.2) - 1.0).abs() < 1e-6);
+    assert!((score_pulse_scale(2.0) - 1.0).abs() < 1e-6);
+}
+
+/// Streak flourish curve must be 1.0 at t=0, peak at t=0.5, and
+/// return to 1.0 at t=duration. Mirrors the `foundation_flourish_scale`
+/// curve test — the two animations share a triangular shape so a
+/// future tweak that desyncs them shows up here.
+#[test]
+fn streak_flourish_scale_curves_through_one_one_one() {
+    let dur = MOTION_STREAK_FLOURISH_SECS;
+    assert!(
+        (streak_flourish_scale(0.0, dur) - 1.0).abs() < 1e-5,
+        "streak flourish scale at t=0 must be 1.0",
+    );
+    assert!(
+        (streak_flourish_scale(dur / 2.0, dur) - STREAK_FLOURISH_PEAK_SCALE).abs() < 1e-5,
+        "streak flourish scale at midpoint must be STREAK_FLOURISH_PEAK_SCALE",
+    );
+    assert!(
+        (streak_flourish_scale(dur, dur) - 1.0).abs() < 1e-5,
+        "streak flourish scale at t=duration must return to 1.0",
+    );
+}
+
+/// Out-of-range values are clamped, not extrapolated. Matches the
+/// foundation flourish's clamp behaviour so the score readout never
+/// freezes at a non-1.0 scale on the frame after the flourish ends.
+#[test]
+fn streak_flourish_scale_clamps_out_of_range() {
+    let dur = MOTION_STREAK_FLOURISH_SECS;
+    assert!((streak_flourish_scale(-1.0, dur) - 1.0).abs() < 1e-5);
+    assert!((streak_flourish_scale(dur * 5.0, dur) - 1.0).abs() < 1e-5);
+}
+
+/// Zero duration (e.g. `AnimSpeed::Instant`) returns identity, never
+/// divides by zero.
+#[test]
+fn streak_flourish_scale_zero_duration_is_one() {
+    assert!((streak_flourish_scale(0.0, 0.0) - 1.0).abs() < 1e-5);
+    assert!((streak_flourish_scale(0.5, 0.0) - 1.0).abs() < 1e-5);
+}
+
+// -----------------------------------------------------------------------
+// Reduce-motion gates — ScorePulse, ScoreFloater, StreakFlourish
+// -----------------------------------------------------------------------
+
+/// Under `Settings::reduce_motion_mode`, a score bump must NOT spawn
+/// a `ScorePulse` on the readout or a `ScoreFloater` on the stage.
+#[test]
+fn score_change_skips_pulse_and_floater_under_reduce_motion() {
+    use solitaire_data::Settings;
+    let mut app = headless_app();
+    app.insert_resource(SettingsResource(Settings {
+        reduce_motion_mode: true,
+        ..Settings::default()
+    }));
+    // +100 would normally create both a ScorePulse and a ScoreFloater.
+    app.world_mut().resource_mut::<GameStateResource>().0.force_test_score(50);
+    app.update();
+    assert_eq!(
+        count_with::<ScorePulse>(&mut app),
+        0,
+        "ScorePulse must not spawn under reduce-motion"
+    );
+    assert_eq!(
+        count_with::<ScoreFloater>(&mut app),
+        0,
+        "ScoreFloater must not spawn under reduce-motion"
+    );
+}
+
+// -----------------------------------------------------------------------
+// Phase 2: keyboard focus ring — HUD action bar
+// -----------------------------------------------------------------------
+
+/// Returns the `Focusable` carried by the unique entity matching
+/// marker `M`. Helper for the HUD focus tests.
+fn focusable_for<M: Component>(app: &mut App) -> Focusable {
+    app.world_mut()
+        .query_filtered::<&Focusable, With<M>>()
+        .iter(app.world())
+        .next()
+        .copied()
+        .unwrap_or_else(|| panic!("no Focusable on the {} button", std::any::type_name::<M>()))
+}
+
+#[test]
+fn hud_buttons_get_focusable_marker() {
+    let mut app = headless_app();
+    // Every action-bar button is in `FocusGroup::Hud`.
+    for f in [
+        focusable_for::<MenuButton>(&mut app),
+        focusable_for::<UndoButton>(&mut app),
+        focusable_for::<PauseButton>(&mut app),
+        focusable_for::<HelpButton>(&mut app),
+        focusable_for::<HintButton>(&mut app),
+        focusable_for::<ModesButton>(&mut app),
+        focusable_for::<NewGameButton>(&mut app),
+    ] {
+        assert_eq!(
+            f.group,
+            FocusGroup::Hud,
+            "every HUD action button must be in FocusGroup::Hud"
+        );
+    }
+}
+
+/// Returns the tooltip string carried by the unique entity matching
+/// marker `M`. Panics if zero or more than one such entity exists,
+/// which is the invariant we want to enforce for HUD readouts and
+/// action buttons (each marker is spawned exactly once).
+fn tooltip_for<M: Component>(app: &mut App) -> String {
+    let mut q = app.world_mut().query_filtered::<&Tooltip, With<M>>();
+    let world = app.world();
+    let mut iter = q.iter(world);
+    let first = iter
+        .next()
+        .unwrap_or_else(|| {
+            panic!(
+                "expected a Tooltip on the {} entity",
+                std::any::type_name::<M>()
+            )
+        })
+        .0
+        .clone()
+        .into_owned();
+    assert!(
+        iter.next().is_none(),
+        "expected exactly one Tooltip-bearing entity for {}",
+        std::any::type_name::<M>()
+    );
+    first
+}
+
+/// Every HUD readout and action button must spawn with a `Tooltip`
+/// carrying the approved canonical microcopy. Mirrors the structure
+/// of `hud_buttons_get_focusable_marker` (Phase 2 focus test) so the
+/// invariant — one marker entity, one tooltip, exact text — is
+/// asserted consistently across every element.
+#[test]
+fn hud_elements_carry_expected_tooltip_strings() {
+    let mut app = headless_app();
+
+    // HUD readouts (left column, top to bottom).
+    assert_eq!(
+        tooltip_for::<HudScore>(&mut app),
+        "Points earned this game. Hidden in Zen mode."
+    );
+    assert_eq!(
+        tooltip_for::<HudMoves>(&mut app),
+        "Moves you've made this game. Counts placements and stock draws."
+    );
+    assert_eq!(
+        tooltip_for::<HudTime>(&mut app),
+        "Time on this game. Counts down in Time Attack."
+    );
+    assert_eq!(
+        tooltip_for::<HudMode>(&mut app),
+        "Active game mode. Click Modes to switch."
+    );
+    assert_eq!(
+        tooltip_for::<HudChallenge>(&mut app),
+        "Today's daily challenge target. Beat it for bonus XP."
+    );
+    assert_eq!(
+        tooltip_for::<HudDrawCycle>(&mut app),
+        "Cards drawn on the next stock click in Draw-Three."
+    );
+    assert_eq!(
+        tooltip_for::<HudUndos>(&mut app),
+        "Undos used this game. Any undo blocks the No Undo achievement."
+    );
+    assert_eq!(
+        tooltip_for::<HudRecycles>(&mut app),
+        "Times you've recycled the stock. Three or more unlocks Comeback."
+    );
+    assert_eq!(
+        tooltip_for::<HudAutoComplete>(&mut app),
+        "Board is solvable from here. Press Enter to auto-finish."
+    );
+    assert_eq!(
+        tooltip_for::<HudSelection>(&mut app),
+        "Pile selected with Tab. Use arrows or Enter to act."
+    );
+
+    // Action bar (left to right).
+    assert_eq!(
+        tooltip_for::<MenuButton>(&mut app),
+        "Open Stats, Achievements, Profile, Settings, or Leaderboard."
+    );
+    assert_eq!(
+        tooltip_for::<UndoButton>(&mut app),
+        "Take back your last move. Costs points and blocks No Undo."
+    );
+    assert_eq!(
+        tooltip_for::<PauseButton>(&mut app),
+        "Pause the game and freeze the timer."
+    );
+    assert_eq!(
+        tooltip_for::<HelpButton>(&mut app),
+        "Show controls, rules, and keyboard shortcuts."
+    );
+    assert_eq!(
+        tooltip_for::<HintButton>(&mut app),
+        "Highlight a suggested move. Cycles through alternatives on repeat taps."
+    );
+    assert_eq!(
+        tooltip_for::<ModesButton>(&mut app),
+        "Switch modes: Classic, Daily, Zen, Challenge, Time Attack."
+    );
+    assert_eq!(
+        tooltip_for::<NewGameButton>(&mut app),
+        "Start a fresh deal. Confirms first if a game is in progress."
+    );
+}
+
+/// Every interior row of the Modes and Menu popovers must carry a
+/// `Tooltip`. The popovers open from action-bar buttons whose own
+/// tooltips are already covered above; this test extends the
+/// invariant inward so hover discoverability is uniform across the
+/// HUD's nested controls.
+///
+/// We invoke the popover spawn helpers directly with a maxed-out
+/// `ProgressResource` and a `DailyChallengeResource` so every row
+/// branch fires (Classic, Daily, Zen, Challenge, Time Attack).
+/// Headless click simulation isn't needed — the contract under
+/// test is "every popover row spawns with a tooltip", which is a
+/// property of the spawn helpers themselves.
+#[test]
+fn popover_rows_carry_tooltip_strings() {
+    use crate::progress_plugin::ProgressResource;
+    use solitaire_sync::progress::PlayerProgress;
+
+    let mut app = headless_app();
+
+    // Force every mode row to render: level past the challenge
+    // unlock threshold, plus a daily challenge resource so the
+    // Daily row appears.
+    let progress = ProgressResource(PlayerProgress {
+        level: CHALLENGE_UNLOCK_LEVEL,
+        ..Default::default()
+    });
+    let daily = DailyChallengeResource {
+        date: Local::now().date_naive(),
+        seed: 1,
+        goal_description: None,
+        target_score: None,
+        max_time_secs: None,
+    };
+
+    // Spawn both popovers via their helpers. Mirrors how the click
+    // handlers invoke them in production — we just skip the click.
+    {
+        let world = app.world_mut();
+        let mut commands = world.commands();
+        spawn_modes_popover(&mut commands, Some(&progress), Some(&daily), None);
+        spawn_menu_popover(&mut commands, None);
+        world.flush();
+    }
+    app.update();
+
+    // Every ModeOption-tagged entity must also carry a Tooltip,
+    // and the count must match the five canonical modes.
+    let mut mode_q = app
+        .world_mut()
+        .query_filtered::<&Tooltip, With<ModeOption>>();
+    let mode_tooltips: Vec<String> = mode_q
+        .iter(app.world())
+        .map(|t| t.0.clone().into_owned())
+        .collect();
+    assert_eq!(
+        mode_tooltips.len(),
+        5,
+        "expected a tooltip on each of the 5 mode rows, got {}",
+        mode_tooltips.len()
+    );
+    // Every approved mode tooltip string must be present somewhere
+    // among the ModeOption rows. Order isn't asserted — the spawn
+    // order test elsewhere already covers that.
+    for expected in [
+        "Standard Klondike. Score, timer, and full progression.",
+        "Today's seeded deal. Same for every player worldwide.",
+        "No timer, no score, no penalties. Just play.",
+        "Hand-picked hard seeds. No undo allowed.",
+        "Win as many games as you can in ten minutes.",
+    ] {
+        assert!(
+            mode_tooltips.iter().any(|s| s == expected),
+            "missing mode tooltip: {expected:?}"
+        );
+    }
+
+    // Same contract for MenuOption rows: seven entries, each with a
+    // tooltip, exact strings matching the approved microcopy.
+    let mut menu_q = app
+        .world_mut()
+        .query_filtered::<&Tooltip, With<MenuOption>>();
+    let menu_tooltips: Vec<String> = menu_q
+        .iter(app.world())
+        .map(|t| t.0.clone().into_owned())
+        .collect();
+    assert_eq!(
+        menu_tooltips.len(),
+        7,
+        "expected a tooltip on each of the 7 menu rows, got {}",
+        menu_tooltips.len()
+    );
+    for expected in [
+        "Show controls, rules, and keyboard shortcuts.",
+        "Switch modes: Classic, Daily, Zen, Challenge, Time Attack.",
+        "Lifetime totals: wins, streaks, fastest time, best score.",
+        "Browse unlocked achievements and the rewards still ahead.",
+        "Your level, XP progress, and sync status.",
+        "Audio, animations, theme, draw mode, and sync.",
+        "Top players from your sync server. Opt in from Profile.",
+    ] {
+        assert!(
+            menu_tooltips.iter().any(|s| s == expected),
+            "missing menu tooltip: {expected:?}"
+        );
+    }
+}
+
+#[test]
+fn hud_button_order_matches_spawn_order() {
+    let mut app = headless_app();
+    // Visual reading order (left → right): Menu, Undo, Pause, Help,
+    // Hint, Modes, New Game. Their `order` fields must be 0..=6 in
+    // that order so Tab cycles them as the player reads them.
+    assert_eq!(focusable_for::<MenuButton>(&mut app).order, 0);
+    assert_eq!(focusable_for::<UndoButton>(&mut app).order, 1);
+    assert_eq!(focusable_for::<PauseButton>(&mut app).order, 2);
+    assert_eq!(focusable_for::<HelpButton>(&mut app).order, 3);
+    assert_eq!(focusable_for::<HintButton>(&mut app).order, 4);
+    assert_eq!(focusable_for::<ModesButton>(&mut app).order, 5);
+    assert_eq!(focusable_for::<NewGameButton>(&mut app).order, 6);
+}
+
+#[test]
+fn hud_focus_only_engages_when_button_hovered() {
+    // Phase 2 declares membership in `FocusGroup::Hud`; the
+    // engagement rule lives in `handle_focus_keys`. Two halves to
+    // this test:
+    //   (a) no modal + no hover ⇒ Tab is a no-op (Phase 1 contract
+    //       still holds when nothing is hovered).
+    //   (b) no modal + a HUD button hovered ⇒ Tab advances
+    //       `FocusedButton` to a Hud-grouped entity.
+    use crate::ui_focus::{FocusedButton, UiFocusPlugin};
+    use crate::ui_modal::UiModalPlugin;
+
+    let mut app = App::new();
+    app.add_plugins(MinimalPlugins)
+        .add_plugins(UiModalPlugin)
+        .add_plugins(UiFocusPlugin)
+        .add_plugins(GamePlugin)
+        .add_plugins(TablePlugin)
+        .add_plugins(HudPlugin);
+    app.init_resource::<ButtonInput<KeyCode>>();
+    app.update();
+
+    // (a) Sanity: HUD buttons exist and are focusable, but no
+    // modal open and no hover ⇒ FocusedButton stays None.
+    assert!(
+        app.world().resource::<FocusedButton>().0.is_none(),
+        "no modal open, no auto-focus"
+    );
+
+    // Press Tab. With no modal and no hover, `handle_focus_keys`
+    // resolves no active group and returns early — Tab must not
+    // advance the HUD focus ring on its own.
+    {
+        let mut input = app.world_mut().resource_mut::<ButtonInput<KeyCode>>();
+        input.release_all();
+        input.clear();
+        input.press(KeyCode::Tab);
+    }
+    app.update();
+
+    assert!(
+        app.world().resource::<FocusedButton>().0.is_none(),
+        "Tab with no modal and no Hud hover must not engage the HUD focus ring"
+    );
+
+    // (b) Hover the Menu button — the leftmost HUD action — and
+    // Tab. The Hud-group cycle should pick a Hud-tagged entity.
+    let menu_entity = app
+        .world_mut()
+        .query_filtered::<Entity, With<MenuButton>>()
+        .iter(app.world())
+        .next()
+        .expect("MenuButton entity should exist");
+    app.world_mut()
+        .entity_mut(menu_entity)
+        .insert(Interaction::Hovered);
+
+    {
+        let mut input = app.world_mut().resource_mut::<ButtonInput<KeyCode>>();
+        input.release_all();
+        input.clear();
+        input.press(KeyCode::Tab);
+    }
+    app.update();
+
+    let focused = app
+        .world()
+        .resource::<FocusedButton>()
+        .0
+        .expect("Tab with a HUD button hovered must engage the HUD focus ring");
+    // The focused entity must itself be Hud-grouped (i.e. one of
+    // the action-bar buttons), not anything else in the world.
+    let focusable = app
+        .world()
+        .entity(focused)
+        .get::<Focusable>()
+        .expect("focused entity must carry Focusable");
+    assert_eq!(
+        focusable.group,
+        FocusGroup::Hud,
+        "Hud-engaged Tab must focus a Hud-grouped entity"
+    );
+}

solitaire_engine/src/hud_plugin/updates.rs

@@ -0,0 +1,612 @@
+//! Per-frame HUD text/typography/visibility updater systems.
+
+use super::*;
+
+use bevy::window::WindowResized;
+use solitaire_core::{Foundation, KlondikePile, Tableau};
+use solitaire_core::Suit;
+use solitaire_core::{DrawStockConfig, game_state::GameMode};
+
+use crate::auto_complete_plugin::AutoCompleteState;
+
+/// Formats a time-limit value in seconds as `"mm:ss"` for HUD display.
+///
+/// For example `format_time_limit(300)` returns `"5:00"`.
+pub fn format_time_limit(secs: u64) -> String {
+    let m = secs / 60;
+    let s = secs % 60;
+    format!("{m}:{s:02}")
+}
+
+// ---------------------------------------------------------------------------
+// Score-change feedback (G2)
+//
+// The flow for each Update tick:
+//   1. `detect_score_change` diffs `GameStateResource.score` against
+//      `PreviousScore`. On any positive delta it inserts/refreshes
+//      `ScorePulse` on the score readout; on a delta ≥
+//      `SCORE_FLOATER_THRESHOLD` it also spawns a floating "+N" UI text
+//      anchored just below the score.
+//   2. `advance_score_pulse` ticks the pulse component, applies the
+//      triangular 1.0 → 1.1 → 1.0 scale curve, and removes the
+//      component on completion.
+//   3. `advance_score_floater` drifts each floater upward, fades it to
+//      transparent, and despawns it when its lifetime expires.
+//
+// The threshold of 50 (a foundation promotion's typical bonus) keeps
+// floaters rare and meaningful — see `SCORE_FLOATER_THRESHOLD`.
+// ---------------------------------------------------------------------------
+
+/// Sets the [`HudWonPreviously`] text to "✓ Won before" whenever the
+/// current deal's seed + draw_mode + mode triple matches an entry in
+/// the rolling [`ReplayHistory`]. Cleared while the active game is won
+/// (the on-screen "Game won!" cue already conveys victory) and on
+/// fresh deals the player hasn't won before.
+///
+/// Lives in its own system rather than `update_hud` to keep this
+/// orthogonal: `update_hud`'s query disambiguation is already busy
+/// enough; threading another marker through every Without filter
+/// would touch ~10 unrelated queries for no benefit.
+pub(super) fn update_won_previously(
+    game: Res<GameStateResource>,
+    // Optional because the HUD plugin's headless tests run without
+    // `StatsPlugin` and therefore without this resource. With the
+    // resource absent there's no history to compare against; the
+    // indicator just stays empty.
+    history: Option<Res<crate::stats_plugin::ReplayHistoryResource>>,
+    mut q: Query<&mut Text, With<HudWonPreviously>>,
+) {
+    let Ok(mut text) = q.single_mut() else {
+        return;
+    };
+    let won_before = !game.0.is_won()
+        && history.as_ref().is_some_and(|h| {
+            h.0.replays.iter().any(|r| {
+                r.seed == game.0.seed && r.draw_mode == game.0.draw_mode() && r.mode == game.0.mode
+            })
+        });
+    let next = if won_before {
+        "\u{2713} Won before"
+    } else {
+        ""
+    };
+    if text.0 != next {
+        text.0 = next.to_string();
+    }
+}
+
+#[allow(clippy::type_complexity, clippy::too_many_arguments)]
+pub(super) fn update_hud(
+    game: Res<GameStateResource>,
+    time_attack: Option<Res<TimeAttackResource>>,
+    daily: Option<Res<DailyChallengeResource>>,
+    auto_complete: Option<Res<AutoCompleteState>>,
+    mut score_q: Query<
+        &mut Text,
+        (
+            With<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut moves_q: Query<
+        &mut Text,
+        (
+            With<HudMoves>,
+            Without<HudScore>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut time_q: Query<
+        &mut Text,
+        (
+            With<HudTime>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut mode_q: Query<
+        &mut Text,
+        (
+            With<HudMode>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut challenge_q: Query<
+        (&mut Text, &mut TextColor),
+        (
+            With<HudChallenge>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut undos_q: Query<
+        (&mut Text, &mut TextColor),
+        (
+            With<HudUndos>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut auto_q: Query<
+        &mut Text,
+        (
+            With<HudAutoComplete>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudRecycles>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut recycles_q: Query<
+        &mut Text,
+        (
+            With<HudRecycles>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudDrawCycle>,
+            Without<HudSelection>,
+        ),
+    >,
+    mut draw_cycle_q: Query<
+        &mut Text,
+        (
+            With<HudDrawCycle>,
+            Without<HudScore>,
+            Without<HudMoves>,
+            Without<HudTime>,
+            Without<HudMode>,
+            Without<HudChallenge>,
+            Without<HudUndos>,
+            Without<HudAutoComplete>,
+            Without<HudRecycles>,
+            Without<HudSelection>,
+        ),
+    >,
+) {
+    let ta_active = time_attack.as_ref().is_some_and(|ta| ta.active);
+
+    // Score, moves, mode, challenge, and undos only need updating when game state changes.
+    if game.is_changed() {
+        let g = &game.0;
+        let is_zen = g.mode == GameMode::Zen;
+        if let Ok(mut t) = score_q.single_mut() {
+            // Zen mode suppresses score display per spec ("No score display").
+            **t = if is_zen {
+                String::new()
+            } else {
+                format!("Score: {}", g.score())
+            };
+        }
+        if let Ok(mut t) = moves_q.single_mut() {
+            **t = format!("Moves: {}", g.move_count());
+        }
+        if let Ok(mut t) = mode_q.single_mut() {
+            **t = match g.mode {
+                GameMode::Classic => match g.draw_mode() {
+                    DrawStockConfig::DrawOne => String::new(),
+                    DrawStockConfig::DrawThree => "Draw 3".to_string(),
+                },
+                GameMode::Zen => "ZEN".to_string(),
+                GameMode::Challenge => "CHALLENGE".to_string(),
+                GameMode::TimeAttack => "TIME ATTACK".to_string(),
+                GameMode::Difficulty(level) => level.label().to_uppercase(),
+            };
+        }
+
+        // --- Daily challenge constraint (with time-low colour warning) ---
+        if let Ok((mut t, mut color)) = challenge_q.single_mut() {
+            if g.is_won() {
+                **t = String::new();
+            } else if let Some(dc) = daily.as_deref() {
+                **t = challenge_hud_text(dc);
+                if let Some(max_secs) = dc.max_time_secs {
+                    let remaining = max_secs.saturating_sub(g.elapsed_seconds);
+                    *color = TextColor(challenge_time_color(remaining));
+                }
+            } else {
+                **t = String::new();
+            }
+        }
+
+        // --- Undo count ---
+        if let Ok((mut t, mut color)) = undos_q.single_mut() {
+            let count = g.undo_count();
+            if count == 0 {
+                **t = String::new();
+                *color = TextColor(TEXT_PRIMARY);
+            } else {
+                **t = format!("Undos: {count}");
+                // STATE_WARNING signals "you took a penalty" — same hue
+                // as the Recycles counter so they read as one category.
+                *color = TextColor(STATE_WARNING);
+            }
+        }
+
+        // --- Recycle counter (both modes, hidden until first recycle) ---
+        if let Ok(mut t) = recycles_q.single_mut() {
+            **t = if g.recycle_count() > 0 {
+                format!("Recycles: {}", g.recycle_count())
+            } else {
+                String::new()
+            };
+        }
+
+        // --- Draw-cycle indicator (Draw-Three mode only) ---
+        if let Ok(mut t) = draw_cycle_q.single_mut() {
+            **t = if g.is_won() || g.draw_mode() != DrawStockConfig::DrawThree {
+                // Hide when not in Draw-Three or after the game is won.
+                String::new()
+            } else {
+                let stock_len = g.stock_cards().len();
+                let next_draw = stock_len.min(3);
+                format!("Cycle: {next_draw}/3")
+            };
+        }
+    }
+
+    // Time display: show Time Attack countdown every frame when active;
+    // Zen mode suppresses the timer per spec ("No timer") — cleared unconditionally
+    // every frame so it disappears immediately on the frame Z is pressed.
+    // Otherwise show game elapsed time (updates once per second via game.is_changed()).
+    let is_zen = game.0.mode == GameMode::Zen;
+    let update_time = (ta_active || game.is_changed()) && !is_zen;
+    if update_time {
+        if let Ok(mut t) = time_q.single_mut() {
+            if let Some(ta) = time_attack.as_ref().filter(|ta| ta.active) {
+                let remaining = ta.remaining_secs.max(0.0) as u64;
+                let m = remaining / 60;
+                let s = remaining % 60;
+                **t = format!("{m}:{s:02}");
+            } else {
+                let secs = game.0.elapsed_seconds;
+                let m = secs / 60;
+                let s = secs % 60;
+                **t = format!("{m}:{s:02}");
+            }
+        }
+    } else if is_zen {
+        // Clear the time display immediately whenever Zen mode is active —
+        // do not guard on game.is_changed() so it clears on the same frame
+        // the player presses Z, before any move is made.
+        if let Ok(mut t) = time_q.single_mut() {
+            **t = String::new();
+        }
+    }
+
+    // --- Auto-complete badge ---
+    // Reflects the AutoCompleteState resource; update whenever it changes or game changes.
+    let ac_active = auto_complete.as_ref().is_some_and(|ac| ac.active);
+    let ac_changed = auto_complete.as_ref().is_some_and(|ac| ac.is_changed());
+    if (ac_changed || game.is_changed())
+        && let Ok(mut t) = auto_q.single_mut()
+    {
+        **t = if ac_active {
+            "AUTO".to_string()
+        } else {
+            String::new()
+        };
+    }
+}
+
+/// Updates the `HudSelection` text node to show which pile is Tab-selected.
+///
+/// Displays `"▶ {pile_name}"` while `SelectionState::selected_pile` is `Some`,
+/// or an empty string when no pile is selected. Runs every frame so the
+/// indicator stays in sync with the selection resource.
+pub(super) fn update_selection_hud(
+    selection: Option<Res<SelectionState>>,
+    game: Option<Res<GameStateResource>>,
+    mut q: Query<&mut Text, With<HudSelection>>,
+) {
+    let Ok(mut t) = q.single_mut() else { return };
+    let label = match selection.as_deref().and_then(|s| s.selected_pile.as_ref()) {
+        None => String::new(),
+        Some(KlondikePile::Stock) => "▶ Waste".to_string(),
+        Some(KlondikePile::Foundation(slot)) => match game.as_deref() {
+            Some(g) => foundation_selection_label(*slot, &g.0),
+            // No game resource means we can't probe claimed_suit; show the
+            // slot-based placeholder so the HUD still surfaces the selection.
+            None => format!("▶ Foundation {}", foundation_number(*slot)),
+        },
+        Some(KlondikePile::Tableau(idx)) => format!("▶ Column {}", tableau_number(*idx)),
+    };
+    **t = label;
+}
+
+/// Returns the HUD selection label for a foundation slot.
+///
+/// When the slot has a claimed suit (any card has landed) the announcement is
+/// "▶ {Suit} Foundation"; while the slot is empty it falls back to a
+/// "▶ Foundation N" placeholder labelled by the 1-based slot index.
+pub(super) fn foundation_selection_label(
+    slot: Foundation,
+    game: &solitaire_core::game_state::GameState,
+) -> String {
+    let claimed = game
+        .pile(KlondikePile::Foundation(slot))
+        .first()
+        .map(|c| c.0.suit());
+    match claimed {
+        Some(suit) => {
+            let s = match suit {
+                Suit::Clubs => "Clubs",
+                Suit::Diamonds => "Diamonds",
+                Suit::Hearts => "Hearts",
+                Suit::Spades => "Spades",
+            };
+            format!("▶ {s} Foundation")
+        }
+        None => format!("▶ Foundation {}", foundation_number(slot)),
+    }
+}
+
+const fn foundation_number(foundation: Foundation) -> u8 {
+    match foundation {
+        Foundation::Foundation1 => 1,
+        Foundation::Foundation2 => 2,
+        Foundation::Foundation3 => 3,
+        Foundation::Foundation4 => 4,
+    }
+}
+
+const fn tableau_number(tableau: Tableau) -> u8 {
+    match tableau {
+        Tableau::Tableau1 => 1,
+        Tableau::Tableau2 => 2,
+        Tableau::Tableau3 => 3,
+        Tableau::Tableau4 => 4,
+        Tableau::Tableau5 => 5,
+        Tableau::Tableau6 => 6,
+        Tableau::Tableau7 => 7,
+    }
+}
+
+/// Fires `InfoToastEvent("Auto-completing...")` exactly once each time
+/// `AutoCompleteState` transitions from inactive to active. Uses a `Local<bool>`
+/// to debounce so the toast only appears on the leading edge.
+pub(super) fn announce_auto_complete(
+    auto_complete: Option<Res<AutoCompleteState>>,
+    mut toast: MessageWriter<InfoToastEvent>,
+    mut was_active: Local<bool>,
+) {
+    let now_active = auto_complete.as_ref().is_some_and(|ac| ac.active);
+    if now_active && !*was_active {
+        toast.write(InfoToastEvent("Auto-completing...".to_string()));
+    }
+    *was_active = now_active;
+}
+
+/// Builds the HUD text for the active daily challenge constraints.
+///
+/// Returns `"Limit: mm:ss"` when a time limit is set, `"Goal: N pts"` when a
+/// score target is set, or an empty string when the challenge has no extra
+/// constraints.
+pub(super) fn challenge_hud_text(dc: &DailyChallengeResource) -> String {
+    if let Some(secs) = dc.max_time_secs {
+        format!("Limit: {}", format_time_limit(secs))
+    } else if let Some(score) = dc.target_score {
+        format!("Goal: {score} pts")
+    } else {
+        String::new()
+    }
+}
+
+/// Returns the colour for the challenge time-limit HUD label based on
+/// seconds remaining. Uses theme tokens so the urgency ramp picks up
+/// palette changes for free.
+///
+/// | Remaining   | Token            |
+/// |-------------|------------------|
+/// | ≥ 60 s      | `STATE_INFO`     |
+/// | 30 – 59 s   | `STATE_WARNING`  |
+/// | < 30 s      | `STATE_DANGER`   |
+pub fn challenge_time_color(remaining: u64) -> Color {
+    if remaining < 30 {
+        STATE_DANGER
+    } else if remaining < 60 {
+        STATE_WARNING
+    } else {
+        STATE_INFO
+    }
+}
+
+/// Scales HUD Tier-1 font sizes to fit a narrow viewport.
+///
+/// Fires on every `WindowResized` event. Below 480 logical pixels wide the
+/// score drops from `TYPE_HEADLINE` (26 px) to `TYPE_BODY_LG` (18 px) and the
+/// Moves/Timer labels drop from `TYPE_BODY_LG` to `TYPE_CAPTION` (11 px), so
+/// all three items remain on one row inside the 50 %-wide HUD column
+/// (≈ 180 dp on a 360 dp phone).  At ≥ 480 px the original sizes are
+/// restored so desktop/tablet layouts are unaffected.
+type HudScoreFont<'w, 's> =
+    Query<'w, 's, &'static mut TextFont, (With<HudScore>, Without<HudMoves>, Without<HudTime>)>;
+type HudMovesFont<'w, 's> =
+    Query<'w, 's, &'static mut TextFont, (With<HudMoves>, Without<HudScore>, Without<HudTime>)>;
+type HudTimeFont<'w, 's> =
+    Query<'w, 's, &'static mut TextFont, (With<HudTime>, Without<HudScore>, Without<HudMoves>)>;
+
+pub(super) fn update_hud_typography(
+    mut events: MessageReader<WindowResized>,
+    mut score_q: HudScoreFont,
+    mut moves_q: HudMovesFont,
+    mut time_q: HudTimeFont,
+) {
+    let Some(ev) = events.read().last() else {
+        return;
+    };
+    let (score_size, secondary_size) = if ev.width < 480.0 {
+        (TYPE_BODY_LG, TYPE_CAPTION)
+    } else {
+        (TYPE_HEADLINE, TYPE_BODY_LG)
+    };
+    for mut font in &mut score_q {
+        font.font_size = score_size;
+    }
+    for mut font in &mut moves_q {
+        font.font_size = secondary_size;
+    }
+    for mut font in &mut time_q {
+        font.font_size = secondary_size;
+    }
+}
+
+pub(super) fn apply_hud_visibility(
+    hud_vis: Res<HudVisibility>,
+    mut action_bar: Query<&mut Visibility, With<HudActionBar>>,
+) {
+    if !hud_vis.is_changed() {
+        return;
+    }
+    let v = if *hud_vis == HudVisibility::Visible {
+        Visibility::Visible
+    } else {
+        Visibility::Hidden
+    };
+    for mut vis in &mut action_bar {
+        *vis = v;
+    }
+    // The bottom action bar is a pure overlay — it does not claim any
+    // space in the card layout, so no WindowResized event is needed.
+}
+
+pub(super) fn restore_hud_on_modal(
+    new_scrims: Query<(), (With<ModalScrim>, Added<ModalScrim>)>,
+    mut hud_vis: ResMut<HudVisibility>,
+) {
+    if !new_scrims.is_empty() {
+        *hud_vis = HudVisibility::Visible;
+    }
+}
+
+/// Returns the action-bar label font size for a given logical window width.
+pub(super) fn action_bar_font_size(window_width: f32) -> f32 {
+    if USE_TOUCH_UI_LAYOUT {
+        // Seven word-labels ("Menu","Undo","Pause","Help","Hint","Mode","New")
+        // must share one row. The widest characters are in FiraMono (a
+        // monospace whose advance is ~0.62 of the font size). On a 900
+        // logical-px phone the row budget after bar padding (2*12) and six
+        // 4 px column gaps is ~852 px for ~28 label chars + 7*2*3 px button
+        // padding. Solving 28*0.62*size + 42 <= 852 gives size <= ~46, so the
+        // labels are advance-bound only on very narrow viewports; the real
+        // constraint is legibility, not fit. ~1/60 of the width yields ~15 px
+        // at 900 px — comfortably one row with margin to spare — clamped so it
+        // never drops below the 12 px legibility floor or grows past 18 px on
+        // landscape tablets where it would crowd the row again.
+        (window_width / 60.0).clamp(12.0, 18.0)
+    } else {
+        TYPE_BODY
+    }
+}
+
+pub(super) fn action_button_metrics() -> (UiRect, Val, Val) {
+    if USE_TOUCH_UI_LAYOUT {
+        // Tight 3 px horizontal padding (down from 4) trims 14 px off the row
+        // total across 7 buttons, and a 44 px min_width (down from 52) lets the
+        // shortest labels ("New", "Help") shrink to their text rather than
+        // padding the row out past the 900 logical-px viewport. min_height
+        // stays at 44 px to preserve the comfortable touch target.
+        (
+            UiRect::axes(Val::Px(3.0), Val::Px(4.0)),
+            Val::Px(44.0),
+            Val::Px(44.0),
+        )
+    } else {
+        (
+            UiRect::axes(VAL_SPACE_2, VAL_SPACE_2),
+            Val::Px(48.0),
+            Val::Px(48.0),
+        )
+    }
+}
+
+pub(super) fn spawn_action_button_label(
+    parent: &mut ChildSpawnerCommands,
+    label: &str,
+    font: &TextFont,
+    text_color: Color,
+) {
+    if USE_TOUCH_UI_LAYOUT {
+        parent.spawn((
+            ActionButtonLabel,
+            Text::new(label),
+            font.clone(),
+            TextColor(text_color),
+        ));
+    } else {
+        parent.spawn((Text::new(label), font.clone(), TextColor(text_color)));
+    }
+}
+
+/// Resizes the glyph text inside every [`ActionButtonLabel`] to match the
+/// current viewport width whenever [`LayoutResource`] changes (orientation
+/// change or window resize).
+#[cfg(target_os = "android")]
+pub(super) fn resize_action_bar_labels(
+    layout: Res<crate::layout::LayoutResource>,
+    windows: Query<&Window>,
+    mut labels: Query<&mut TextFont, With<ActionButtonLabel>>,
+) {
+    let w = windows
+        .iter()
+        .next()
+        .map_or(layout.0.card_size.x * 7.25, |win| win.width());
+    let new_size = action_bar_font_size(w);
+    for mut font in &mut labels {
+        font.font_size = new_size;
+    }
+}
+