docs(handoff): mark WASM script + 401-retry test complete; update HEAD state

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -1,88 +0,0 @@
-name: CI
-
-on:
-  push:
-    branches: [master]
-  pull_request:
-    branches: [master]
-
-env:
-  CARGO_TERM_COLOR: always
-  RUSTFLAGS: "-D warnings"
-
-jobs:
-  test:
-    name: Test & Lint
-    runs-on: ubuntu-latest
-
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Install Rust stable
-        uses: dtolnay/rust-toolchain@stable
-        with:
-          components: clippy
-
-      - name: Install Linux audio/display dependencies
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -y --no-install-recommends \
-            libasound2-dev \
-            libudev-dev \
-            libwayland-dev \
-            libxkbcommon-dev
-
-      - name: Cache cargo registry and build artifacts
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-
-
-      - name: Clippy (all crates, zero warnings)
-        run: cargo clippy --workspace -- -D warnings
-
-      - name: Test (headless crates only — no display required)
-        run: |
-          cargo test -p solitaire_core
-          cargo test -p solitaire_sync
-          cargo test -p solitaire_data
-          cargo test -p solitaire_server
-
-  build:
-    name: Release Build
-    runs-on: ubuntu-latest
-    needs: test
-
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Install Rust stable
-        uses: dtolnay/rust-toolchain@stable
-
-      - name: Install Linux audio/display dependencies
-        run: |
-          sudo apt-get update -qq
-          sudo apt-get install -y --no-install-recommends \
-            libasound2-dev \
-            libudev-dev \
-            libwayland-dev \
-            libxkbcommon-dev
-
-      - name: Cache cargo registry and build artifacts
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.cargo/registry
-            ~/.cargo/git
-            target
-          key: ${{ runner.os }}-cargo-release-${{ hashFiles('**/Cargo.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-cargo-release-
-
-      - name: Build release binaries
-        run: cargo build --workspace --release

.gitignore

@@ -7,3 +7,11 @@
 *.tmp
 data/
 .claude/
+
+# IDE project files
+.idea/
+
+# Android signing keystores — never commit
+*.jks
+*.jks.bak
+*.keystore

.sqlx/query-168e205e3eb832b78d085b48281a1bae74d5a0e64c4c793c18a6400605bacf76.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "DELETE FROM refresh_tokens WHERE jti = ?",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": []
+  },
+  "hash": "168e205e3eb832b78d085b48281a1bae74d5a0e64c4c793c18a6400605bacf76"
+}

.sqlx/query-893c45c27854ba15ea611e8254ef980ced21dc64e6ca95fde56af513f86ffa46.json

@@ -0,0 +1,20 @@
+{
+  "db_name": "SQLite",
+  "query": "SELECT jti FROM refresh_tokens WHERE jti = ?",
+  "describe": {
+    "columns": [
+      {
+        "name": "jti",
+        "ordinal": 0,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      true
+    ]
+  },
+  "hash": "893c45c27854ba15ea611e8254ef980ced21dc64e6ca95fde56af513f86ffa46"
+}

.sqlx/query-c9ee5c64ca547f0c730379919a642bd649cbf81fc1804159101a70efabf08b33.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "INSERT INTO refresh_tokens (jti, user_id, expires_at) VALUES (?, ?, ?)",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 3
+    },
+    "nullable": []
+  },
+  "hash": "c9ee5c64ca547f0c730379919a642bd649cbf81fc1804159101a70efabf08b33"
+}

.sqlx/query-ef7af925a8715c329dcafca5257c691e6bca31755eb5f54be47114f21fc04c8c.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "DELETE FROM refresh_tokens WHERE expires_at < ?",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": []
+  },
+  "hash": "ef7af925a8715c329dcafca5257c691e6bca31755eb5f54be47114f21fc04c8c"
+}

ARCHITECTURE.md

@@ -1,9 +1,9 @@
 # Solitaire Quest — Architecture Document
 
-> **Version:** 1.1  
+> **Version:** 1.3  
 > **Language:** Rust (Edition 2024)  
 > **Engine:** Bevy (latest stable)  
-> **Last Updated:** 2026-04-29
+> **Last Updated:** 2026-05-12
 
 ---
 
@@ -86,6 +86,7 @@ solitaire_quest/
 ├── solitaire_data/             # Persistence, sync client, settings
 ├── solitaire_engine/           # Bevy ECS systems, components, plugins
 ├── solitaire_server/           # Self-hosted sync server (Axum + SQLite)
+├── solitaire_wasm/             # WebAssembly bindings — browser-side replay player
 └── solitaire_app/              # Main binary entry point
 ```
 
@@ -160,6 +161,20 @@ Owns:
 - Daily challenge seed generation
 - Leaderboard management
 
+### `solitaire_wasm`
+**Dependencies:** `solitaire_core`, `serde`, `serde_json`, `chrono`, `wasm-bindgen`, `serde-wasm-bindgen`.
+
+WebAssembly bindings for browser-side replay playback. Compiled to `cdylib` via `wasm-pack build`; the output lives in `solitaire_server/web/pkg/` and is served statically by the server.
+
+Intentionally **does not** depend on `solitaire_data` (which pulls in `dirs`, `keyring`, `reqwest`, and other non-WASM crates). Instead it defines a minimal `Replay` mirror with the same serde shape as `solitaire_data::Replay` — the JSON wire format is the compatibility contract.
+
+Owns:
+- `ReplayPlayer` — WASM-exported state machine; steps through a replay's `Vec<ReplayMove>` against a live `GameState`
+- `StateSnapshot` — JS-facing pile snapshot returned by each `step()` call
+- `ReplayMove` / `Replay` mirrors — same serde shape as `solitaire_data` v2 equivalents
+
+Because `ReplayPlayer` uses the same `solitaire_core::GameState` as the desktop client, the two implementations cannot drift: the same seed + move list produces identical pile state at every step on both platforms.
+
 ### `solitaire_app`
 **Dependencies:** `bevy`, `solitaire_engine`.
 
@@ -261,6 +276,8 @@ The "Shortcut" column lists optional keyboard accelerators. Every action in this
 | `HomePlugin` | M | Main-menu overlay with keyboard shortcut reference |
 | `ProfilePlugin` | P | Player profile overlay: level, XP, achievements, sync status |
 | `SettingsPlugin` | O | Settings panel: audio, draw mode, theme, sync, cosmetics |
+| `ThemePlugin` | — | Owns `ActiveTheme` resource; registers the `CardTheme` SVG asset loader; rasterises themes once per (theme, target size) at load time and caches the resulting `Image`; handles the embedded default theme and user themes from `user_theme_dir()` |
+| `SyncSetupPlugin` | — | Sync setup modal (URL / username / password fields, "Log In" / "Register" buttons); account deletion confirm modal; re-auth trigger when `SyncError::Auth` is returned by a pull |
 | `LeaderboardPlugin` | L | Leaderboard overlay |
 | `HelpPlugin` | H | Help / controls overlay |
 | `PausePlugin` | Esc | Pause and resume |
@@ -365,10 +382,22 @@ All sync backends implement a single trait in `solitaire_data`. The `SyncPlugin`
 ```rust
 #[async_trait]
 pub trait SyncProvider: Send + Sync {
+    // Required — must be implemented by every backend:
     async fn pull(&self) -> Result<SyncPayload, SyncError>;
     async fn push(&self, payload: &SyncPayload) -> Result<SyncResponse, SyncError>;
     fn backend_name(&self) -> &'static str;
     fn is_authenticated(&self) -> bool;
+
+    // Optional — all have default no-op / empty implementations:
+    async fn mirror_achievement(&self, _id: &str) -> Result<(), SyncError>;
+    async fn fetch_leaderboard(&self) -> Result<Vec<LeaderboardEntry>, SyncError>;
+    async fn fetch_daily_challenge(&self) -> Result<Option<ChallengeGoal>, SyncError>;
+    async fn opt_in_leaderboard(&self, _display_name: &str) -> Result<(), SyncError>;
+    async fn opt_out_leaderboard(&self) -> Result<(), SyncError>;
+    async fn delete_account(&self) -> Result<(), SyncError>;
+    // Returns the shareable web URL on success; defaults to Err(UnsupportedPlatform)
+    // so LocalOnlyProvider silently no-ops the push-on-win path.
+    async fn push_replay(&self, _replay: &Replay) -> Result<String, SyncError>;
 }
 ```
 
@@ -454,6 +483,24 @@ CREATE TABLE leaderboard (
     recorded_at     TEXT NOT NULL,
     PRIMARY KEY (user_id)
 );
+
+-- migrations/002_replays.sql
+
+CREATE TABLE IF NOT EXISTS replays (
+    id              TEXT PRIMARY KEY,                      -- UUID v4 minted server-side
+    user_id         TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    seed            INTEGER NOT NULL,
+    draw_mode       TEXT NOT NULL,                          -- "DrawOne" | "DrawThree"
+    mode            TEXT NOT NULL,                          -- "Classic" | "Zen" | "Challenge" | "TimeAttack"
+    time_seconds    INTEGER NOT NULL,
+    final_score     INTEGER NOT NULL,
+    recorded_at     TEXT NOT NULL,                          -- replay-side date (YYYY-MM-DD)
+    received_at     TEXT NOT NULL,                          -- server insert timestamp (ISO 8601)
+    replay_json     TEXT NOT NULL                           -- full Replay serialisation
+);
+
+CREATE INDEX IF NOT EXISTS replays_received_at_idx ON replays(received_at DESC);
+CREATE INDEX IF NOT EXISTS replays_user_id_idx     ON replays(user_id);
 ```
 
 ### Request Lifecycle
@@ -584,7 +631,20 @@ pub struct Settings {
     pub animation_speed: AnimSpeed,
     pub theme: Theme,
     pub sync_backend: SyncBackend,             // Local | SolitaireServer
+    pub selected_card_back: usize,             // index into PlayerProgress::unlocked_card_backs
+    pub selected_background: usize,            // index into PlayerProgress::unlocked_backgrounds
     pub first_run_complete: bool,
+    pub color_blind_mode: bool,                // blue tint on red suits
+    pub high_contrast_mode: bool,              // boosted luminance for low-vision users
+    pub reduce_motion_mode: bool,              // WCAG reduce-motion — snaps instead of slides
+    pub window_geometry: Option<WindowGeometry>, // persisted size + position; None on first run
+}
+
+pub struct WindowGeometry {
+    pub width:  u32,   // logical pixels
+    pub height: u32,
+    pub x:      i32,   // physical pixels, top-left corner
+    pub y:      i32,
 }
 ```
 
@@ -600,7 +660,7 @@ All endpoints are under the base URL configured by the user (e.g., `https://soli
 |---|---|---|---|---|
 | POST | `/api/auth/register` | None | `{username, password}` | `{access_token, refresh_token}` |
 | POST | `/api/auth/login` | None | `{username, password}` | `{access_token, refresh_token}` |
-| POST | `/api/auth/refresh` | None | `{refresh_token}` | `{access_token}` |
+| POST | `/api/auth/refresh` | None | `{refresh_token}` | `{access_token, refresh_token}` (rotated) |
 
 ### Sync
 
@@ -617,6 +677,21 @@ All endpoints are under the base URL configured by the user (e.g., `https://soli
 | GET | `/api/leaderboard` | Bearer JWT | — | `Vec<LeaderboardEntry>` |
 | POST | `/api/leaderboard/opt-in` | Bearer JWT | — | `{ok: true}` |
 
+### Replays
+
+| Method | Path | Auth | Body | Response |
+|---|---|---|---|---|
+| POST | `/api/replays` | Bearer JWT | Replay JSON | `{id, share_url}` |
+| GET | `/api/replays/recent` | None | — (`?limit=N`) | `Vec<ReplaySummary>` |
+| GET | `/api/replays/:id` | None | — | Full Replay JSON |
+
+### Web Replay Player
+
+| Method | Path | Auth | Notes |
+|---|---|---|---|
+| GET | `/replays/:id` | None | Serves `web/index.html`; JS fetches `/api/replays/:id` and steps through via the `solitaire_wasm` WASM module |
+| GET | `/web/*` | None | Static assets served via `ServeDir` from `solitaire_server/web/` (includes `web/pkg/` with wasm-bindgen output) |
+
 ### Account Management
 
 | Method | Path | Auth | Body | Response |
@@ -945,6 +1020,7 @@ Migrations run automatically on startup via `sqlx::migrate!()`.
 | Password storage | bcrypt, cost factor 12 — never stored in plaintext |
 | Token security | JWTs signed with HS256, stored in OS keychain via `keyring` crate |
 | Token expiry | Access: 24h, Refresh: 30d |
+| Refresh token rotation | Each `/api/auth/refresh` call consumes the incoming refresh token (deletes its jti row) and issues a new one. Reuse of a consumed token returns 401. Expired rows are pruned inline. |
 | Brute force | `tower-governor`: 10 req/min per IP on `/api/auth/*` |
 | Payload abuse | 1MB max request body, enforced by Axum middleware |
 | Data deletion | `DELETE /api/account` removes all rows via `ON DELETE CASCADE` |

CHANGELOG.md

@@ -6,8 +6,897 @@ project follows [Semantic Versioning](https://semver.org/).
 
 ## [Unreleased]
 
-No threads in flight. v0.21.1 cut on 2026-05-08; CHANGELOG accumulates
+---
-the next cycle here.
+
+## [0.23.0] — 2026-05-12
+
+Phase 8 sync UI: the self-hosted-server connection flow is now fully
+playable end-to-end. Players can open a Connect modal from Settings,
+enter a server URL + credentials, log in or register, and see the
+sync-status section update live. Token expiry auto-reopens the modal.
+Account deletion ships a two-click destroy flow. Server deployment
+artifacts (Dockerfile + docker-compose) let self-hosters spin up in one
+command.
+
+### Added
+
+- **Sync setup modal — Connect / Disconnect flow** (`432061c`).
+  New `SyncSetupPlugin` (`solitaire_engine/src/sync_setup_plugin.rs`)
+  provides the full server-connection UI. Three tab-stopped text fields
+  (URL, Username, Password) handle keyboard input via `MessageReader<KeyboardInput>`
+  with focus cycling on Tab. "Log In" and "Register" buttons each spawn an
+  async `AsyncComputeTaskPool` task that calls the new
+  `SolitaireServerClient::login()` / `::register()` methods; `poll_auth_task`
+  harvests the result, stores tokens via `store_tokens()`, hot-swaps
+  `SyncProviderResource` to the new server backend, fires
+  `ManualSyncRequestEvent` to pull immediately, and closes the modal.
+  An inline `SyncAuthError` label displays credential errors without a
+  toast. The modal is idempotent (`existing.is_empty()` guard) — safe
+  to open programmatically.
+- **`SyncConfigureRequestEvent`, `SyncLogoutRequestEvent`,
+  `DeleteAccountRequestEvent`** (`432061c`). Three new engine events
+  wire the Settings buttons → plugin handlers. `SyncConfigureRequestEvent`
+  opens the setup modal; `SyncLogoutRequestEvent` disconnects and resets
+  `SyncProviderResource` to `LocalOnlyProvider`; `DeleteAccountRequestEvent`
+  opens the deletion confirmation modal.
+- **Settings sync section — dynamic backend UI** (`432061c`).
+  `sync_row()` in `SettingsPlugin` now takes `backend: &SyncBackend` and
+  renders conditionally: `Local` → "Connect" button; `SolitaireServer` →
+  username label + "Sync Now" + "Disconnect" + "Delete Account". Three new
+  `SettingsButton` discriminants (`ConnectSync` tab 91, `DisconnectSync`
+  tab 92, `DeleteAccount` tab 93) feed into a new `handle_sync_buttons`
+  system extracted from `handle_settings_buttons` to stay within Bevy's
+  16-parameter system limit.
+- **`SolitaireServerClient::login()` and `::register()`** (`432061c`).
+  Both POST to `/api/auth/login` and `/api/auth/register` respectively.
+  Private helper `extract_auth_tokens` parses `{ access_token, refresh_token }`.
+  409 CONFLICT → "username already taken"; 401/403 → "invalid credentials";
+  400 → server message echoed to the player.
+- **Re-auth prompt on token expiry** (`6ce5564`).
+  `poll_pull_result` in `SyncPlugin` now fires `InfoToastEvent("Session
+  expired — please reconnect")` + `SyncConfigureRequestEvent` when the
+  pull task resolves to `SyncError::Auth(_)`. Because the modal is
+  idempotent the re-open is safe to trigger from any system path.
+- **Server deployment artifacts** (`6ce5564`).
+  `solitaire_server/Dockerfile`: multi-stage build (`rust:1.95-slim` →
+  `debian:bookworm-slim`); copies `.sqlx` offline cache so `SQLX_OFFLINE=true`
+  succeeds without a live database at build time; exposes port 8080.
+  `solitaire_server/docker-compose.yml`: single-service compose file;
+  `db-data` volume at `/app/data`; `DATABASE_URL` and `JWT_SECRET` from
+  environment; HTTP health-check via `wget`. `solitaire_server/.env.example`:
+  documents all required variables with generation hint (`openssl rand -hex 32`).
+- **Account deletion flow** (`272d31f`).
+  "Delete Account" in Settings fires `DeleteAccountRequestEvent` →
+  `SyncSetupPlugin::open_delete_confirm_modal` spawns a danger-red
+  confirmation modal with "Cancel" and "Delete Forever" buttons.
+  "Delete Forever" submits an async `PendingDeleteTask` that calls
+  `SyncProvider::delete_account()`; `poll_delete_task` on Ok fires
+  `SyncLogoutRequestEvent` + a success toast; on Err shows an error toast
+  and leaves the modal open. Two-click destroy pattern — no accidental
+  account deletion possible.
+
+### Removed
+
+- **`SyncAuthResultEvent`** (`432061c`). Defined but never emitted or
+  consumed; removed as dead code.
+
+### Stats
+
+- Tests: **1300+ passing** / 0 failing
+- Clippy: clean
+- Crates touched: `solitaire_data` (sync_client), `solitaire_engine`
+  (events, settings_plugin, sync_plugin, sync_setup_plugin [new], lib),
+  `solitaire_app` (lib.rs), `solitaire_server` (Dockerfile,
+  docker-compose.yml, .env.example [new])
+
+## [0.22.0] — 2026-05-08
+
+Adds difficulty-tier game selection, Android JNI bridges for keystore and
+clipboard, Play-by-Seed dialog, and double-tap auto-move on touch screens.
+Also closes the Prev/Next replay-selector spawn-site item carried since v0.19.0.
+
+### Added
+
+- **Difficulty-tier game mode** (this release).
+  `DifficultyLevel` enum (`Easy / Medium / Hard / Expert / Grandmaster /
+  Random`) added to `solitaire_core::game_state` alongside a new
+  `GameMode::Difficulty(DifficultyLevel)` variant. Five pre-verified seed
+  catalogs (40 seeds each, 200 total) are generated by the new
+  `gen_difficulty_seeds` binary in `solitaire_assetgen`; each catalog
+  contains seeds proven winnable at progressively larger solver budgets
+  (1 K → 200 K moves). `DifficultyPlugin` resolves `StartDifficultyRequestEvent`
+  → catalog seed → `NewGameRequestEvent`; the `Random` tier uses a
+  system-time seed and intentionally bypasses the winnable-only filter.
+  The home overlay gains an expandable `▶ Difficulty` section between the
+  Draw Mode row and the mode-card grid; the last-played tier is persisted
+  in `Settings::last_difficulty` and pre-expands/highlights on re-open.
+  Difficulty wins pool into Classic stats (no separate buckets).
+- **Prev/Next replay selector in the Stats overlay** (`a449f60`).
+  `ReplayPrevButton`, `ReplayNextButton`, `ReplaySelectorCaption`, and
+  `ReplaySelectorDetail` nodes now spawn inside `spawn_stats_screen`
+  as a flex row of two bordered chips flanking a `"Replay N / M"`
+  caption, with a detail line below showing the selected replay's
+  duration + date and an optional `"· Shareable"` badge. Both chips
+  carry `ModalButton(Secondary)` so the existing `repaint_modal_buttons`
+  paint loop gives them hover/press feedback at zero extra cost.
+  `repaint_replay_selector_detail` is wired into the existing
+  `.chain()` alongside `handle_replay_selector_buttons` and
+  `repaint_replay_selector_caption`. The click handler and repaint
+  systems have been registered (and dormant) since v0.19.0; this
+  commit is purely the missing spawn site.
+- **6 new selector unit tests** (`a449f60`). Covers: spawn-site
+  presence (Prev, Next, Caption, Detail all spawn with the screen),
+  caption initial text ("Replay 1 / 1"), detail initial text
+  ("{dur} win on {date}"), Shareable badge when `share_url` is set,
+  empty-history "No replays" caption, and ordinal wrapping.
+  `make_test_replay(time_seconds, share_url)` helper encapsulates
+  `Replay::new(...)` + `chrono::NaiveDate`.
+
+### Fixed
+
+- **`const { assert!() }` for dim-layer z-order test** (`a449f60`).
+  Converted `assert!(Z_REPLAY_DIM < Z_REPLAY_OVERLAY, …)` in
+  `replay_overlay` tests to `const { assert!(…) }` to satisfy
+  `clippy::assertions_on_constants` (constant-fold at compile time
+  rather than a runtime no-op).
+
+### Added (post-cut, same pending release)
+
+- **Double-tap auto-move on touch screens** (`395a322`).
+  `handle_double_tap` fires `MoveRequestEvent` (single card to
+  foundation/tableau, or a whole face-up stack via
+  `best_tableau_destination_for_stack`) when two `TouchPhase::Ended`
+  events on the same card arrive within `DOUBLE_TAP_WINDOW` (0.5 s,
+  slightly wider than the mouse `DOUBLE_CLICK_WINDOW` to account for
+  touch latency). If no legal destination exists, fires
+  `MoveRejectedEvent` (audio + visual rejection feedback).  The system
+  is inserted into the touch drag chain immediately before
+  `touch_end_drag` so `DragState.active_touch_id` and `committed` are
+  still readable; the tap timestamp is tracked in a `Local<HashMap<u32,
+  f32>>` keyed by card ID.
+- **Play-by-Seed dialog** (`0cb1587`).
+  `PlayBySeedPlugin` adds a numeric-input modal that accepts a decimal
+  seed, runs a solver preview in the background (debounced 500 ms via
+  `AsyncComputeTaskPool`), and shows a win/no-win verdict before
+  dealing.  A new `HomeMode::PlayBySeed` card in the home overlay fires
+  `StartPlayBySeedRequestEvent`; the handler in `PlayBySeedPlugin`
+  spawns the dialog.  Digit, Backspace, Enter (confirm), and Escape
+  (cancel) are handled via `ButtonInput<KeyCode>`.  Five unit tests
+  cover spawn, digit append, buffer read, confirm, and cancel paths.
+- **75 new challenge seeds** (`2062bd0`).
+  New `gen_seeds` binary in `solitaire_assetgen` brute-searches seeds
+  in the `0xCAFEBABE…` namespace and filters for hands solvable in
+  ≤250 moves via the core solver.  The 75 confirmed-win seeds are
+  appended to `CHALLENGE_SEEDS` in `solitaire_data::challenge`.
+
+### Fixed (post-cut, same pending release)
+
+- **Gate `handle_fullscreen` to non-Android** (`45436d0`).
+  F11 fullscreen toggle makes no sense on Android (the OS owns window
+  sizing); the fn and its `MonitorSelection`/`WindowMode` imports are
+  now `#[cfg(not(target_os = "android"))]`-gated.  The `add_systems`
+  call is extracted as a separate statement so `#[cfg]` can annotate it
+  (attributes cannot appear mid-chain in Rust).
+- **Android APK launch: export `android_main`** (`202a64d`).
+  `NativeActivity` dlopen-s `libsolitaire_app.so` and calls
+  `android_main` as its entry point. Without the symbol the app
+  crashed immediately with `UnsatisfiedLinkError`. The new function
+  sets `bevy::android::ANDROID_APP` (required by `WinitPlugin`) then
+  delegates to `run()` — equivalent to what `#[bevy_main]` would
+  generate, but usable on an arbitrary entry point name.
+- **Android APK launch: gate `resize_constraints` to non-Android**
+  (`202a64d`). On Android `max_width/max_height` default to `0.0`;
+  Bevy's clamp panicked with `min=800 > max=0`.
+- **Android APK launch: gate `apply_smart_default_window_size` to
+  non-Android** (`202a64d`). The system calls `.clamp(800.0,
+  logical_w)` which panics when the emulator reports zero window
+  dimensions during early Android lifecycle events. The OS controls
+  window size on Android; the system is irrelevant there.
+- **Ignore `.idea/` IDE project files** (`16242e6`). Android Studio
+  created `.idea/` when the project was opened during APK
+  verification; added to `.gitignore` and removed the accidentally-
+  committed files.
+
+### Android verification result
+
+APK boots on `x86_64-linux-android` in a Pixel_7 AVD (Android 14 /
+API 34, SwiftShader Vulkan). App runs for 2+ minutes without crashing.
+Bevy renderer initialises, splash screen loads. This is the first
+confirmed end-to-end device run.
+
+### Stats
+
+- Tests: **1300+ passing** / 0 failing
+- Clippy: clean
+- Crates touched: `solitaire_core` (game_state), `solitaire_data`
+  (settings, stats, difficulty_seeds, challenge), `solitaire_engine`
+  (events, difficulty_plugin, home_plugin, hud_plugin, win_summary_plugin,
+  input_plugin, play_by_seed_plugin, lib), `solitaire_app` (lib.rs),
+  `solitaire_assetgen` (gen_difficulty_seeds + gen_seeds binaries)
+
+## [0.21.8] — 2026-05-08
+
+Patch release for replay-overlay polish. Through-line:
+**notch-label centering + WIN MOVE HC legibility + HC system extension**.
+All three items were "optional polish" flagged in the v0.21.7 handoff;
+all three ship in two commits.
+
+### Added
+
+- **`STATE_SUCCESS_HC` constant** (`c50eaf8`). Brighter lime
+  (`#c8e862`, L≈0.73) in `ui_theme` for use wherever the
+  standard `STATE_SUCCESS` (`#acc267`, L≈0.51) needs extra
+  luminance under HC mode. Sits above the bumped notch ticks
+  (`BORDER_SUBTLE_HC` gray, L≈0.60) so a WIN MOVE marker at
+  this colour is unambiguous.
+- **`HighContrastBackground::with_hc(default, hc)` constructor**
+  (`c50eaf8`). Extends `HighContrastBackground` with an
+  `hc_color: Color` field (default = `BORDER_SUBTLE_HC` via
+  `with_default()`). `update_high_contrast_backgrounds` now
+  reads `marker.hc_color` instead of the hardcoded constant —
+  backwards-compatible; all existing `with_default()` usages
+  continue to bump to gray.
+- **WIN MOVE scrub-bar marker HC bump** (`c50eaf8`). Marker
+  now carries `HighContrastBackground::with_hc(STATE_SUCCESS,
+  STATE_SUCCESS_HC)` so the lime stays lime under HC (brighter
+  lime rather than gray). Pin test locks both the default and
+  HC colour fields on the spawned entity.
+
+### Fixed
+
+- **Scrub-bar notch-label centering** (`b44d277`). Middle
+  three labels ("25%", "50%", "75%") previously had their
+  left edge at the notch; now their text centre coincides
+  with the notch tick. Implemented using the CSS
+  `translateX(-50%)` pattern for Bevy 0.18 UI: a fixed
+  `SCRUB_LABEL_CENTER_WIDTH = 36 px` container with
+  `margin.left = -18 px` is placed at `left: Percent(pct)`,
+  and `Justify::Center` centres the text within it. Endpoint
+  labels ("0%", "100%") keep their flush-left / flush-right
+  anchoring. `with_default()` remains one-argument.
+
+### Stats
+
+- Tests: 1276 passing / 0 failing (engine: 831)
+- Clippy: clean
+- Crates touched: `solitaire_engine` (replay_overlay.rs,
+  ui_theme.rs, settings_plugin.rs)
+
+## [0.21.7] — 2026-05-08
+
+Patch release closing the last major B-2 sub-piece. Through-line:
+**mini-tableau preview dim layer**. The mockup's "Game Peek Band at
+50 % opacity" is now implemented as a full-screen UI scrim that darkens
+the card world during replay so the chrome (banner + move-log panel)
+reads clearly against the scene.
+
+### Added
+
+- **Full-screen tableau dim layer** (`da3e542`). Spawns a
+  `ReplayTableauDimLayer` UI node (100 % × 100 %, 50 % opacity
+  black) at `Z_REPLAY_DIM = Z_REPLAY_OVERLAY − 1 = 54` whenever
+  a replay starts; despawned alongside the banner and move-log
+  panel when the replay ends. Bevy's UI/world compositor means
+  no changes to `card_plugin` are needed — UI nodes always
+  render above world-space sprites regardless of `Transform.z`.
+  The dim layer carries no `Interaction` component (purely
+  visual; pointer events pass through). Adds `Z_REPLAY_DIM`
+  and `TABLEAU_DIM_ALPHA` constants plus two new tests:
+  lifecycle (spawn/despawn mirrors the floating-chip pattern)
+  and z-ordering invariant (`Z_REPLAY_DIM < Z_REPLAY_OVERLAY`
+  pinned). 1275 tests pass / 0 failing.
+
+### Stats
+
+- Tests: 1275 passing / 0 failing
+- Clippy: clean
+- Crates touched: `solitaire_engine` (replay_overlay.rs)
+
+## [0.21.6] — 2026-05-08
+
+Patch release for the post-v0.21.5 work. Through-line:
+**Move Log panel + scrub-UX polish**. v0.21.5 closed out the
+keyboard-accelerator surface (Space / Esc / ← / →) and the
+keybind footer; v0.21.6 builds on that with two parallel
+threads — accessibility + scrub-on-hold polish for the v0.21.5
+surfaces, plus a brand-new Move Log panel anchored to the
+viewport's bottom edge that gives players a 5-row recent-and-
+upcoming move history alongside the existing top-edge banner.
+
+The Move Log panel is the first replay-overlay surface that
+*isn't* attached to the banner — it lives at a separate screen
+anchor (bottom: 0) with its own spawn/despawn lifecycle.
+Establishes the pattern for "multi-anchor replay UI" that the
+remaining B-2 sub-piece (mini-tableau preview) will inherit.
+
+### Added
+
+- **HC-mode coverage for the scrub track + quarter-mark notch
+  ticks** (`d3cb1a5`). Adds parallel primitive
+  `HighContrastBackground` to `ui_theme` and a paint system
+  `update_high_contrast_backgrounds` in `settings_plugin` that
+  mirrors the existing border-marker pattern but targets
+  `BackgroundColor` instead of `BorderColor`. Tags the 1 px
+  scrub track Node and all five quarter-mark notch ticks so
+  they bump from `BORDER_SUBTLE` (`#505050`) →
+  `BORDER_SUBTLE_HC` (`#a0a0a0`) under HC mode. Scrub fill
+  (`ACCENT_PRIMARY`) and WIN MOVE marker (`STATE_SUCCESS`)
+  don't get the marker — accent and state colours are already
+  saturated and don't need an HC luminance variant.
+- **Continuous scrub on key-held arrow keys** (`2e25476`).
+  Holding ← or → triggers continuous step at 100 ms cadence
+  (10 steps/sec) — matches the mockup's `[← →] scrub`
+  terminology while keeping single-press = single-step
+  semantics. Per-key accumulators in a new
+  `ReplayScrubKeyHold` resource; `just_pressed` events bypass
+  the accumulator and fire immediately. Release resets to 0
+  so the next fresh press fires immediately rather than at
+  half-interval.
+- **Move Log panel** (`d6f32d3` + `140251b` + `e7345ae` +
+  `4437a1a`). New bottom-edge UI panel showing a 5-row window
+  onto recent + upcoming moves: 2 prev rows above the active
+  row + active row highlighted in `ACCENT_PRIMARY` + 2 next
+  rows below. Header reads `▌ MOVE LOG · N/M` (or
+  `▌ MOVE LOG · COMPLETE` when finished). Active row carries
+  a `▶` focus prefix and `TEXT_PRIMARY_HC` text colour for
+  legible contrast against the brick-red highlight. Prev /
+  next rows render in `TEXT_SECONDARY` so the active row
+  stays the focal point.
+  - Sibling-of-banner pattern (separate root entity anchored
+    at viewport bottom, not a banner child) — same
+    spawn/despawn lifecycle as `ReplayFloatingProgressChip`,
+    different screen anchor.
+  - Five pure helpers handle the formatting:
+    `format_pile`, `format_move_body`,
+    `format_move_log_header`, `format_kth_recent_row` (active
+    + prev), `format_kth_next_row` (next). 1-indexed display
+    numbers throughout (`Foundation(2)` reads as "foundation
+    3" rather than the enum's 0-index).
+  - Panel grows from 56 → 84 → 112 px across the four
+    move-log commits. `MOVE_LOG_PREV_ROWS` and
+    `MOVE_LOG_NEXT_ROWS` constants (both = 2) parameterise
+    the row count; `format_kth_recent_row` and
+    `format_kth_next_row` return empty for out-of-range k so
+    panels gracefully under-fill at the start (cursor=1) and
+    end (cursor=N-1) of a replay.
+  - HC marker on the panel's top border so the 1 px edge
+    bumps under HC mode (same pattern as the keybind footer).
+
+### Changed
+
+- **`react_to_state_change` despawns the Move Log panel** on
+  `Playing → Inactive` alongside the banner root and floating
+  progress chip. Third query in the same defer-and-despawn
+  cycle.
+- **Move Log panel height grew 56 → 84 → 112 px** across the
+  prev-rows and next-rows commits. The panel is sized to fit
+  the chosen row count + header + padding; tunable via the
+  `MOVE_LOG_PANEL_HEIGHT` const.
+- **`format_active_move_row` now prefixes the `▶` focus
+  marker** (`e7345ae`). Wraps `format_kth_recent_row(state, 1)`
+  and prepends the prefix when the body is non-empty. Empty
+  case still returns empty — cursor=0 doesn't paint a stray
+  `▶` on an otherwise-empty row.
+
+### Documentation
+
+- `SESSION_HANDOFF.md` refreshed twice this cycle — once
+  recording the HC paint + continuous-scrub polish, then
+  again as the Move Log arc shipped commit-by-commit. The
+  Resume menu's B option now traces the full arc:
+  notches → labels → footer → ESC → HC → arrow keys →
+  HC paint → continuous scrub → move log.
+
+### Stats
+
+- **1273 passing tests / 0 failing** across the workspace
+  (net +23 from v0.21.5's 1250 baseline):
+  - 2 from `d3cb1a5` (HC marker on track + notches).
+  - 2 from `2e25476` (continuous-scrub repeat-while-held +
+    release-resets-accumulator).
+  - 8 from `d6f32d3` (move-log panel init + 5 helpers + 3
+    spawn / lifecycle scenarios).
+  - 4 from `140251b` (prev rows: helper k coverage + spawn
+    cardinality + spawn texts + repaint on cursor advance).
+  - 3 from `e7345ae` (active row highlight: wrapper bg +
+    text colour + focus prefix + cursor=0 stays empty).
+  - 4 from `4437a1a` (next rows: helper k coverage + spawn
+    cardinality + spawn texts + under-fill at replay end).
+- Clippy clean across the workspace.
+
+## [0.21.5] — 2026-05-08
+
+Patch release for the post-v0.21.4 work. One through-line:
+**replay-overlay scrubbing affordances + accessibility**. v0.21.4
+shipped pause / resume / step + the WIN MOVE marker as the first
+*scrubbing-shaped* additions to the replay overlay; v0.21.5
+fills out the rest of the scrubbing UX so the player has both
+visual anchor points (notches + labels) and a complete keyboard
+control surface (Space / Esc / ← / →) for navigating a paused
+replay.
+
+Two of the six commits in this cycle are layout-changing — they
+grow the banner height from 60 px → 76 px → 92 px to make room
+for the notch labels and keybind footer. Banner geometry was
+fixed for every prior B-2 commit; this release establishes the
+"grow the container, add a flex-column child" pattern that the
+remaining B-2 sub-pieces (move-log scroller, mini-tableau
+preview) will inherit when they land.
+
+### Added
+
+- **Quarter-mark scrub-bar notches** (`fe68861`). Five 1 px
+  vertical ticks at 0 / 25 / 50 / 75 / 100 % give the player
+  visual anchor points without needing to mentally bisect the
+  bar. Pure helper `scrub_notch_positions()` returns the fixed
+  array; spawn loop sits next to the WIN MOVE marker spawn so
+  the lifecycles match. Notches paint in `BORDER_SUBTLE` (same
+  as the unfilled track) and rely on extending past the 1 px
+  track (5 px tall, anchored 2 px above the track top) for
+  visibility — same trick the WIN MOVE marker uses. Spawned
+  *after* the WIN MOVE marker so a notch and the marker
+  landing on the same percentage paint the marker on top.
+- **Percentage labels under each notch** (`d322abf`). Five
+  `0%` / `25%` / `50%` / `75%` / `100%` labels in a new 16 px
+  row beneath the 1 px scrub track give the player explicit
+  quarter-mark readouts. Banner grew from 60 → 76 px to
+  accommodate the row — first **layout-changing** commit in
+  the B-2 arc. Pure helper `scrub_notch_labels()` returns the
+  fixed array, paired index-for-index with
+  `scrub_notch_positions()`. Spawn loop applies an "endpoints
+  flush, middle three percent-anchored" positioning pattern:
+  leftmost label gets `left: 0`, rightmost gets `right: 0`,
+  middle three anchor at `left: Val::Percent(p)` since Bevy
+  0.18 UI lacks a clean CSS-style `translate-x: -50%`
+  centering primitive. Label colour is `TEXT_SECONDARY`
+  rather than the mockup's `BORDER_SUBTLE` (the latter would
+  match the notches but is too low-contrast against
+  `BG_ELEVATED_HI` to read at 12 px).
+- **Keybind-hint footer** (`1873b3f`). Vim-style mode line on
+  the left (`▌ NORMAL │ replay`) plus a keybind hint on the
+  right at the bottom edge of the banner. Banner grew from
+  76 → 92 px to fit the 16 px footer row. Surfaces every
+  wired keyboard accelerator visually so CLAUDE.md §3.3's
+  UI-first contract holds for keyboard accelerators too. The
+  footer lists *only* keybinds that are actually wired —
+  the only-wired-keybinds discipline means each release
+  cycle's hint string is a precise honest contract with the
+  player. Two pure helpers (`keybind_footer_mode_text`,
+  `keybind_footer_hint_text`) keep the static text testable.
+  1 px top border in `BORDER_SUBTLE` separates the footer
+  from the labels row.
+- **ESC keyboard accelerator for replay-stop** (`90e24d9`).
+  New `handle_stop_keyboard` system parallels
+  `handle_pause_keyboard` in shape — fires only when state
+  is `Playing`, calls `stop_replay_playback`. Cross-plugin
+  coordination via `pause_plugin::toggle_pause`: added a
+  fourth defer-if check
+  (`replay_state.is_some_and(|s| s.is_playing())`) right
+  after the existing `other_modal_scrims` check so ESC
+  during active replay belongs to the replay overlay, not
+  the pause modal.
+- **HC-mode coverage for the keybind-footer top border**
+  (`23902cd`).
+  `HighContrastBorder::with_default(BORDER_SUBTLE)` marker
+  on the footer's border-carrying Node so the existing
+  `apply_high_contrast_borders` system bumps the 1 px top
+  border from `#505050` → `#a0a0a0` when
+  `Settings::high_contrast_mode` is on. Without the marker
+  the footer reads as floating loose under HC because the
+  border that anchors it to the labels row is
+  near-invisible.
+- **← / → keyboard accelerators for paused stepping**
+  (`e5c4f51`). New `step_backwards_replay_playback` in
+  `replay_playback.rs` decrements the cursor and dispatches
+  `UndoRequestEvent`; the game's `handle_undo` reads it
+  next frame to reverse its most-recent move. Hooks the
+  existing undo system rather than replaying-forward-from-
+  zero — every replay-applied move pushes to the undo stack
+  the same way a player move would, so undo is the right
+  reversal primitive. Both arrow keys are paused-only via
+  the same destructure-gate pattern the forward step uses.
+  The mockup labels these `[← →] scrub`; single-move step
+  is the closest behaviour shippable today, so the footer
+  hint reads `[← →] step` — only-wired-keybinds discipline.
+
+### Changed
+
+- **Banner height grew 60 → 76 → 92 px** across two
+  layout-changing commits (`d322abf` then `1873b3f`). Top
+  row's `flex_grow: 1.0` still consumes 59 px so the
+  existing content (label / progress chip / buttons) has
+  the same vertical space; the new rows (16 px labels +
+  16 px footer) extend the banner downward into the
+  gameplay area. Banner geometry is now mutable — every
+  prior B-2 commit fit inside fixed 60 px space.
+- **Keybind-footer hint text grew alongside the wirings**:
+  `[SPACE] pause/resume` →
+  `[SPACE] pause/resume · [ESC] stop` →
+  `[SPACE] pause/resume · [ESC] stop · [← →] step`.
+- **`pause_plugin::toggle_pause` now defers when a replay
+  is active** (`90e24d9`). Adds a fourth defer-if check to
+  the existing modal-stack pattern.
+- **`ReplayOverlayPlugin` registers
+  `add_message::<UndoRequestEvent>()`** (`e5c4f51`).
+  Defensive registration so the plugin runs cleanly under
+  `MinimalPlugins` without `GamePlugin` attached.
+
+### Documentation
+
+- `SESSION_HANDOFF.md` refreshed five times this cycle.
+  The B option in the Resume menu now traces the full arc:
+  notches → labels → footer → ESC → HC → arrow keys.
+- The pre-existing `daily_challenge` warning test that
+  fails when wall-clock UTC is within 30 minutes of
+  midnight is documented in this cycle's handoff. Same
+  shape as the earlier `winnable_seed_search` flake —
+  time-dependent, deterministically passes outside the
+  trigger window.
+
+### Stats
+
+- **1250 total tests / 1249 passing / 1 pre-existing
+  time-dependent flake** across the workspace (net +22 from
+  v0.21.4's 1228 baseline):
+  - 4 from `fe68861` (scrub-notch coverage)
+  - 4 from `d322abf` (notch-label coverage)
+  - 4 from `1873b3f` (keybind-footer coverage)
+  - 3 from `90e24d9` (ESC-accelerator coverage)
+  - 1 from `23902cd` (HC-marker coverage)
+  - 6 from `e5c4f51` (arrow-keyboard coverage)
+- **Pre-existing flake**:
+  `daily_challenge_plugin::tests::check_system_fires_warning_event_only_once_per_day`
+  fails when wall-clock UTC is within 30 minutes of
+  midnight. Verified pre-existing by stash-and-retest
+  before each commit. Will pass deterministically outside
+  the trigger window. Not introduced by this release.
+- Clippy clean across the workspace.
+
+## [0.21.4] — 2026-05-08
+
+Patch release for the post-v0.21.3 work. One through-line:
+**replay-scrubbing accessibility**. The replay overlay used to be
+pure-passive — the player started a replay, watched it execute,
+and waited for it to end. v0.21.4 adds the scaffolding for
+*navigating within* a replay: a WIN MOVE marker on the scrub bar
+so the player can see at a glance where the winning move sits,
+and pause / resume / step controls so they can stop on any move
+and inspect the board.
+
+The work is also the first three commits on the B-2 replay
+screen-takeover redesign arc. The remaining pieces (screen-
+takeover layout, move-log scroller, mini-tableau preview) are
+deferred to a future cycle because they need a layout reflow
+that the existing banner-only overlay can't carry.
+
+### Added
+
+- **`Replay::win_move_index: Option<usize>` data field**
+  (`ab857bb`). Additive optional field on the persisted
+  `Replay` shape. `#[serde(default)]` keeps older
+  `latest_replay.json` / `replays.json` files loadable without
+  bumping `REPLAY_SCHEMA_VERSION` — this is purely additive.
+  Populated at the live recording site
+  (`game_plugin::handle_game_won`) via a new builder-style
+  setter `Replay::with_win_move_index`. For fresh recordings
+  the value is always `Some(moves.len() - 1)` because recording
+  freezes on win, but storing it explicitly lets the playback
+  UI read the WIN MOVE position directly without re-deriving
+  on every render.
+- **WIN MOVE scrub-bar marker** (`52befa6`). New
+  `ReplayOverlayWinMoveMarker` component spawned as a sibling
+  to `ReplayOverlayScrubFill` under the 1px scrub track,
+  absolute-positioned at `replay.win_move_index / total %` of
+  the bar. Painted in `STATE_SUCCESS` (green) so the marker
+  reads as "this is where the win lives." Pure helper
+  `win_move_marker_pct` returns `None` for any state where the
+  marker shouldn't draw (Inactive, Completed, replay missing
+  the field, empty move list); percentage clamps to `[0, 100]`
+  defensively. Spawn-time only — the position never changes
+  during a single playback because the underlying `Replay` is
+  immutable while `Playing`.
+- **Pause / Resume / Step playback controls** (`fbe48ac`). New
+  `paused: bool` field on `ReplayPlaybackState::Playing`.
+  `tick_replay_playback` skips the `secs_to_next` decrement
+  entirely while paused so cursor and timer freeze together;
+  resuming starts the next move from a full interval. New
+  public API: `toggle_pause_replay_playback` and
+  `step_replay_playback` (the latter hard-gated to `Playing {
+  paused: true }` via the destructure pattern itself, so
+  manual stepping can't race the tick loop). On-screen Pause
+  and Step buttons sit alongside the existing Stop button;
+  `Space` keyboard accelerator toggles pause / resume.
+- **`Replay::with_win_move_index` builder** (`ab857bb`).
+  Chainable setter so the recording site can write
+  `Replay::new(...).with_win_move_index(idx)`. Keeps
+  `Replay::new`'s signature stable across the 13+ existing
+  test-fixture call sites that don't care about the field.
+
+### Changed
+
+- **`Replay::new` writes `win_move_index: None`** (`ab857bb`).
+  Existing canonical constructor stays signature-compatible
+  with all existing callers. The field is opt-in via the
+  builder.
+- **`game_plugin::handle_game_won` populates the new field**
+  (`ab857bb`). The recording site computes
+  `recording.moves.len().checked_sub(1)` as the win-move
+  index. `checked_sub` rather than direct subtraction guards
+  the unreachable empty-recording branch (which is also
+  guarded earlier in the function).
+- **`tick_replay_playback` honors the new `paused` flag**
+  (`fbe48ac`). Skipping the timer decrement is the only
+  behavior change; the loop body and Completed-detection are
+  unchanged. Stepping fires moves directly via
+  `step_replay_playback`, bypassing the tick path entirely.
+- **Pause / Resume button label is reactive** (`fbe48ac`).
+  `update_pause_button_label` walks `Children` from the
+  marked button to its inner `Text` and repaints the label
+  whenever `ReplayPlaybackState` changes. Pure helper
+  `pause_button_label` covers all four state arms (running,
+  paused, inactive, completed).
+- **25 existing `Playing { ... }` construction sites gained
+  `paused: false`** (`fbe48ac`). Mechanical edit across
+  `replay_overlay`, `achievement_plugin`, and
+  `replay_playback` tests to satisfy the new field
+  requirement. No behavioral change.
+
+### Documentation
+
+- `SESSION_HANDOFF.md` refreshed three times this cycle —
+  once after each post-cut feature commit. The B-2 entry in
+  the Visual-identity follow-ups list now points at the
+  remaining sub-pieces (screen-takeover layout, move-log
+  scroller, mini-tableau preview) as a single multi-session
+  arc rather than three independent ones, since they share a
+  layout-reflow prerequisite.
+
+### Stats
+
+- **1228 passing tests / 0 failing** across the workspace
+  (net +21 from v0.21.3's 1207 baseline):
+  - 5 from `ab857bb`'s `win_move_index` coverage: default
+    constructor, builder set / set-None, on-disk round-trip,
+    legacy-JSON-loads-with-None backward-compat. The last
+    test pins the no-schema-bump claim — if a future refactor
+    drops the `#[serde(default)]`, that test catches it.
+  - 8 from `52befa6`'s WIN MOVE marker: pure-helper truth
+    table (Inactive / Completed / no-field / correct-position
+    / clamp) + spawn-presence-with-field /
+    spawn-absence-without / despawn-with-overlay observables.
+  - 8 from `fbe48ac`'s playback controls: label truth table,
+    label repaint on state change, click-toggles-paused,
+    step advances cursor by exactly one with paused
+    preserved, step-while-running no-op, Space toggles
+    paused.
+- Zero clippy warnings under `cargo clippy --workspace
+  --all-targets -- -D warnings`.
+- `cargo test --workspace` clean.
+
+## [0.21.3] — 2026-05-08
+
+Patch release for the post-v0.21.2 work. One through-line:
+**accessibility arc closure**. v0.21.2 explicitly carved out
+"dynamic-paint sites" (HUD action buttons, modal buttons, radial
+menu rim) on the assumption that their existing paint cycles would
+race the central `update_high_contrast_borders` system. v0.21.3
+walks the actual code, finds the carve-out was over-cautious, and
+closes it. Bonus: the first real consumer of `ToastVariant::Warning`
+also lands here, making the `ToastVariant` enum fully load-bearing
+(every variant has at least one driver).
+
+### Added
+
+- **`WarningToastEvent(String)` — first `ToastVariant::Warning`
+  consumer** (`279e23d`). Generic carrier message that any system
+  can fire to spawn a 4 s amber-bordered fire-and-forget toast.
+  Mirrors the v0.21.2 `MoveRejectedEvent` → `Error` toast wiring:
+  domain message crosses the plugin boundary, the animation
+  plugin's `handle_warning_toast` system reads it and spawns. Not
+  queued (Warning is alert-shaped, not info-shaped — should never
+  block on a queue).
+- **Daily-challenge-expiry warning** (`279e23d`). First in-engine
+  driver of `WarningToastEvent`. New
+  `daily_challenge_plugin::check_daily_expiry_warning` system
+  fires at most once per `DailyChallengeResource::date` when the
+  player is within 30 min of UTC midnight reset and today's
+  challenge isn't yet complete. Suppression decided by a pure
+  helper (`compute_expiry_warning_minutes`) covering: already-
+  completed-today, already-shown-for-this-date, outside the
+  threshold window, post-midnight rollover. Pure-helper-plus-
+  thin-system shape because `Utc::now()` can't be pinned without
+  injecting a clock resource — overkill for one consumer.
+- **`radial_rim_outline` pure helper** (`c153363`). Decision
+  logic for the radial-menu rim outline colour. Resting outlines
+  always carry `BORDER_SUBTLE`; focused outlines carry
+  `BORDER_STRONG` normally and `BORDER_SUBTLE_HC` under HC. Naive
+  marker substitution would invert the focused-vs-resting
+  hierarchy because `BORDER_SUBTLE_HC` (`#a0a0a0`) is *lighter*
+  than `BORDER_STRONG` (`#505050`); folding the choice in here
+  keeps the focused rim more visible under HC, not less.
+
+### Changed
+
+- **HC marker pattern extended to HUD action buttons + modal
+  buttons** (`c153363`). Re-reading the code revealed both sites'
+  paint systems (`paint_action_buttons`, `paint_modal_buttons`)
+  only mutate `BackgroundColor` — `BorderColor` is set once at
+  spawn and never touched. So the existing
+  `HighContrastBorder::with_default(BORDER_SUBTLE)` marker
+  pattern works cleanly for both, no race. v0.21.2's carve-out
+  comment was based on assumed-but-not-actual race risk; this
+  cycle treats it as the doc-vs-implementation drift pattern in
+  the wild and verifies before trusting.
+- **Radial menu rim folds HC into per-frame respawn**
+  (`c153363`). The rim is the only true dynamic-painter of the
+  three carved-out sites — `radial_redraw_overlay` despawns and
+  respawns all rim sprites every frame the radial is `Active`.
+  The `HighContrastBorder` marker can't apply (entities don't
+  persist across frames) so HC is read directly in the system
+  via `Option<Res<SettingsResource>>` and routed through
+  `radial_rim_outline`. The `Option<Res<...>>` shape preserves
+  test compatibility under `MinimalPlugins`.
+- **Animation plugin registers `WarningToastEvent`** (`279e23d`).
+  Joins `InfoToastEvent`, `MoveRejectedEvent` etc. in
+  `AnimationPlugin::build`. Daily-challenge plugin also
+  registers it (idempotent) so the message exists when running
+  the daily plugin under `MinimalPlugins` without the animation
+  plugin attached.
+
+### Documentation
+
+- `SESSION_HANDOFF.md` refreshed twice this cycle — once after
+  the Toast Warning wiring (menu trimmed 5 → 4 options), and
+  again after the HC dynamic-paint rollout (menu trimmed 4 → 3,
+  with all remaining options now flagged as multi-session). The
+  `High-contrast accessibility mode` entry in the Visual-identity
+  follow-ups list is updated to reflect that no "un-tagged
+  because race-risk" surfaces remain.
+
+### Stats
+
+- **1207 passing tests / 0 failing** across the workspace
+  (net +12 from v0.21.2's 1195 baseline):
+  - 7 tests for `compute_expiry_warning_minutes` (`279e23d`)
+    covering each suppression rule + the inclusive boundary at
+    exactly 30 min remaining.
+  - 1 in-Bevy test (`check_system_fires_warning_event_only_once_per_day`)
+    pinning `DailyExpiryWarningShown`'s once-per-date
+    suppression and the symmetric "already-completed-today"
+    suppression.
+  - 4 truth-table tests for `radial_rim_outline` (`c153363`):
+    focused × HC. The "resting stays subtle under HC" test
+    explicitly documents *why* — it's the hierarchy-preservation
+    invariant a future refactor might be tempted to break.
+- Zero clippy warnings under `cargo clippy --workspace
+  --all-targets -- -D warnings`.
+- `cargo test --workspace` clean.
+
+## [0.21.2] — 2026-05-08
+
+Patch release for the post-v0.21.1 polish work. Three through-
+lines: **accessibility extensions** (reduce-motion gating for
+splash animations, full HC chrome rollout across 8 surfaces),
+**replay polish** (floating MOVE chip above the focused card
+during playback), and the **first real consumer of
+`ToastVariant::Error`** (invalid-move feedback as the third leg
+of the existing audio + visual rejection-feedback stool).
+
+The accessibility extensions close two threads v0.21.1 left
+explicitly open: reduce-motion was previously gated only on card
+slide_secs, and HC borders had `BORDER_SUBTLE_HC` defined but no
+consumers. v0.21.2 finishes both — non-essential motion in the
+splash boot screen now respects reduce-motion, and every static-
+border chrome surface (modal scaffold, tooltip, help / stats /
+home / settings panels) boosts to the HC variant under high-
+contrast mode. Dynamic-paint sites (HUD action buttons, modal
+buttons, radial menu rim) intentionally stay un-tagged because
+their existing paint cycles would race the HC system; they
+remain open for a future iteration that needs a different shape.
+
+### Added
+
+- **`sync_pile_marker_visibility` system precursor was v0.21.1's;
+  this cycle adds**: `update_high_contrast_borders` system in
+  `settings_plugin` (`c9af1ea`). Walks all entities tagged with
+  `HighContrastBorder` each Update tick, swaps `BorderColor` to
+  `BORDER_SUBTLE_HC` when high-contrast mode is on. Compares
+  current colour and only mutates when different so Bevy's
+  change-detection doesn't trigger repaints every frame. New
+  `HighContrastBorder { default_color: Color }` component carries
+  the off-state colour at each tagged site so the system can
+  revert correctly.
+- **HC chrome rollout — 8 tagged surfaces** (`c9af1ea` modal
+  scaffold; `d87761d` tooltip + onboarding key chips + help
+  panel key chips + stats panel cells; `ec804d5` home Level/XP/
+  Score row + home mode-selector buttons + home mode-hotkey
+  chips + 4 settings panel surfaces). Each tagging is one line
+  on the spawn tuple. The marker-component architecture pays
+  back proportionally to the number of consumers — the per-
+  commit cost dropped from ~75 lines (foundation + first
+  surface) to ~13 lines (4 surfaces) to ~9 lines (7 surfaces).
+- **Floating MOVE chip during replay** (`2fb2d63`). New
+  `ReplayFloatingProgressChip` marker on a `Text2d` entity
+  rendered in 2D world space above the destination pile of the
+  most-recently-applied move. Sibling of the banner overlay (not
+  a child) because it lives in world-space coordinates, not the
+  UI tree. Lifecycle matches the banner: `spawn_overlay` spawns
+  the chip alongside the banner when a replay starts;
+  `react_to_state_change` despawns it when the replay ends.
+  World-space placement (rather than UI-space + camera projection)
+  uses the same `LayoutResource` pile coordinates that drive
+  every other piece of pile geometry — stays correctly positioned
+  through window resizes for free. Hidden when cursor=0 (no
+  moves applied yet) or when the last applied move was a
+  `StockClick` (no destination pile to follow).
+- **`handle_move_rejected_toast` system + first real
+  `ToastVariant::Error` consumer** (`68d50b5`). When
+  `MoveRejectedEvent` fires (illegal placement attempt), spawns
+  a 2-second pink-bordered "Invalid move" toast. Joins the
+  existing `card_invalid.wav` (audio cue) and destination-pile
+  shake (visual cue) as the accessibility-focused readable text
+  channel — covers deaf players (no audio reliance) and
+  reduce-motion players (no shake reliance) with a persistent
+  ~2 s text cue. Drops the `#[allow(dead_code)]` from
+  `ToastVariant::Error` and updates its doc to point at the new
+  consumer.
+
+### Changed
+
+- **Splash scanline overlay skipped under reduce-motion**
+  (`ed152e2`). `spawn_splash` reads `Settings::reduce_motion_mode`
+  and skips the scanline texture / overlay node entirely when
+  on. Without the scanlines the boot screen still reads as
+  terminal-themed (foreground content, borders, palette swatches
+  unchanged); the scanlines are decorative.
+- **Splash cursor pulse held under reduce-motion** (`ed152e2`).
+  `pulse_splash_cursor` reads `Settings::reduce_motion_mode` and
+  skips the per-frame sine-pulse multiplier when on — the cursor
+  still fades in / out with the global splash alpha (essential
+  timing) but doesn't blink. Spec calls out non-essential motion
+  as the reduce-motion target; the global fade is essential
+  (otherwise the splash would hard-cut on/off, which is
+  jarring), and the cursor blink is decorative.
+- **`AnimationPlugin::build` registers
+  `MoveRejectedEvent`** (`68d50b5`). Bevy's `add_message` is
+  idempotent, so the duplicate registration with
+  `feedback_anim_plugin` (which already registered the message)
+  coexists cleanly. Required for the new
+  `handle_move_rejected_toast` system to run under
+  MinimalPlugins (tests).
+
+### Documentation
+
+- `docs/ui-mockups/design-system.md` and `SESSION_HANDOFF.md`
+  refreshed in lockstep with the rollouts. The handoff's
+  Resume-prompt menu trimmed twice this cycle as Options A and F
+  closed in v0.21.1, then this commit cycle's accessibility
+  extensions implicitly closed the "future scope" footnotes
+  v0.21.1 left on F's documentation.
+
+### Stats
+
+- **1195 passing tests / 0 failing** across the workspace
+  (net +3 from v0.21.1's 1192 baseline). New tests added by
+  this cycle:
+  - `splash_skips_scanline_overlay_under_reduce_motion`
+    (`ed152e2`) pins the reduce-motion gate on the splash
+    scanline overlay. Discovered an asset-fixture bootstrapping
+    detail along the way: under `MinimalPlugins`,
+    `Assets<Image>` isn't auto-inserted; the test had to add
+    `bevy::asset::AssetPlugin::default()` and
+    `init_asset::<bevy::image::Image>()`. Pattern flagged for
+    future asset-using tests.
+  - `floating_chip_spawns_and_despawns_with_overlay`
+    (`2fb2d63`) pins the floating MOVE chip's lifecycle:
+    absent on Inactive, exactly one on Playing, absent again
+    on return to Inactive.
+  - `move_rejected_event_spawns_error_toast` (`68d50b5`) pins
+    the new toast wiring: firing a `MoveRejectedEvent` spawns
+    exactly one `ToastOverlay` on the next tick.
+- Zero clippy warnings under `cargo clippy --workspace
+  --all-targets -- -D warnings`.
+- `cargo test --workspace` clean.
 
 ## [0.21.1] — 2026-05-08
 

Cargo.lock

@@ -6967,6 +6967,8 @@ version = "0.1.0"
 dependencies = [
  "ab_glyph",
  "png 0.17.16",
+ "solitaire_core",
+ "solitaire_data",
 ]
 
 [[package]]
@@ -6984,8 +6986,10 @@ version = "0.1.0"
 dependencies = [
  "async-trait",
  "axum",
+ "bevy",
  "chrono",
  "dirs",
+ "jni 0.21.1",
  "jsonwebtoken",
  "keyring-core",
  "reqwest",
@@ -7009,6 +7013,7 @@ dependencies = [
  "bevy",
  "chrono",
  "dirs",
+ "jni 0.21.1",
  "kira",
  "resvg",
  "ron",

Cargo.toml

@@ -31,6 +31,7 @@ keyring     = "4"
 keyring-core = "1"
 reqwest     = { version = "0.13", features = ["json", "rustls", "rustls-native-certs"], default-features = false }
 arboard     = { version = "3", default-features = false }
+jni         = { version = "0.21", default-features = false }
 
 solitaire_core   = { path = "solitaire_core" }
 solitaire_sync   = { path = "solitaire_sync" }

SESSION_HANDOFF.md

@@ -1,313 +1,160 @@
 # Solitaire Quest — Session Handoff
 
-**Last updated:** 2026-05-08 — **v0.21.0 cut and tagged at `04f9bf9`**,
+**Last updated:** 2026-05-12 — WASM build script + push-retry test shipped (`198df75`). HEAD locally: `198df75`. Push pending.
-working tree clean, all post-tag work pushed to origin.
 
-v0.21.0 closes the visual-identity arc opened in v0.20.0. Three
+Phase 8 closes the self-hosted-server connection arc end-to-end: login/register
-through-lines landed in this cycle: the **card-face / suit /
+modal, re-auth on token expiry, account deletion flow, server deployment
-card-back artwork migration** that v0.20.0 deliberately deferred
+artifacts (Dockerfile + docker-compose), replay upload on win, web replay
-(both rendering paths in lockstep — `assets/cards/*.png` fallback
+player (WASM + HTML/CSS/JS served by the server), leaderboard opt-in/out,
-plus the bundled-default theme SVGs at
+and full server integration tests.
-`solitaire_engine/assets/themes/default/*.svg` that
-`include_bytes!()`-embed into the binary), the **splash boot-
-screen + replay-overlay polish** that closed Resume-prompt
-Options B and C, and a late-cycle **`ACCENT_PRIMARY` palette
-swap** from cyan `#6fc2ef` to brick red `#a54242` after a quick
-stakeholder review of the shipped art.
 
-Full v0.21.0 detail lives in `CHANGELOG.md` § [0.21.0]. This
+---
-file from here on focuses on what's *open* post-cut and how to
-resume.
 
-## Status at pause
+## Current state
 
-- **HEAD locally:** see `git rev-parse HEAD`. The cut commit is
+- **HEAD locally:** `198df75` (test: push retry + build_test_pool).
-  `04f9bf9`; any post-cut docs edits ride on top of that.
+- **HEAD on origin:** `08f74d1` (pushed — 3 commits ahead).
-- **HEAD on origin:** matches local. v0.21.0 is fully on origin.
+- **Working tree:** `SESSION_HANDOFF.md` modified, uncommitted.
-- **Working tree:** clean. No WIP outstanding.
+- **Build:** `cargo clippy --workspace --all-targets -- -D warnings` clean.
-- **`artwork/` directory:** still untracked. Intentional.
+- **Tests:** **1300+ passing / 0 failing** across the workspace.
-- **Build:** `cargo clippy --workspace --all-targets -- -D warnings`
+- **Tags on origin:** `v0.9.0` through `v0.22.0`.
-  clean.
-- **Tests:** **1184 passing / 0 failing** across the workspace
-  (net +8 from v0.20.0's 1176 baseline). Detail in
-  `CHANGELOG.md` § [0.21.0] § Stats.
-- **Tags on origin:** `v0.9.0` through `v0.21.0`. v0.21.0 is on
-  `04f9bf9`; v0.20.0 stays on `41a009a`.
 
-## Since the v0.21.0 cut
+---
 
-Two Resume-prompt options closed post-tag (2026-05-08):
+## What shipped in Phase 8 (432061c – bd388fe)
 
-- **Option A — App icon round** (`3eb3a26` + `716a025`). 9-size
+| Commit | Summary |
-  PNG hierarchy in `assets/icon/` (16/24/32/48/64/128/256/512/
+|--------|---------|
-  1024 px), generated by a new `icon_generator` example from a
+| `432061c` | Sync setup modal (login/register/connect/disconnect) |
-  shared `icon_svg` builder (Terminal `▌RS` mark on dark
+| `6ce5564` | Re-auth on expired session + server deployment artifacts |
-  `#151515` with brick-red accent). Runtime `Window::icon`
+| `272d31f` | Account deletion flow + `handle_sync_buttons` refactor |
-  wired via `WinitWindows` on desktop only (Android draws its
+| `bd388fe` | CHANGELOG v0.23.0 documentation |
-  launcher icon from the APK manifest). The follow-up fix
-  `716a025` wraps `NonSend<WinitWindows>` in `Option<...>`
-  to satisfy Bevy 0.18's stricter system-param validation —
-  the resource doesn't exist on the first few frames before
-  winit's `Resumed` event fires. New deps (target-gated
-  non-Android): direct `winit = "0.30"` for `Icon`
-  construction, direct `tiny-skia` for PNG → RGBA decode.
-  Pin test `icon_svg_pin` guards future rasteriser drift.
-- **Option F — Accessibility modes** (`c5787c6` + `07e0357`).
-  High-contrast and reduce-motion settings flags wired through
-  the engine and surfaced as Settings panel toggles. HC boosts
-  `RED_SUIT_COLOUR` to `#ff8aa0` and `BLACK_SUIT_COLOUR` to
-  `#f5f5f5` for card text rendering; reduce-motion forces
-  `effective_slide_secs` to 0 regardless of `AnimSpeed`. CBM
-  and HC compose: lime CBM wins on red when both are on; HC
-  still applies to black suits when both are on. Six new
-  tests pin the truth tables. UI toggles sit alongside the
-  Color-blind row in Settings → Cosmetic; tab-walk visits
-  all three accessibility flags in one vertical run.
 
-Three Resume-prompt options remain live: B (APK launch
+Also shipped (pre-Phase 8 but post-v0.22.0, already in CHANGELOG):
-verification), C (replay-overlay extensions), D (Toast
+- `solitaire_wasm` crate: WASM ReplayPlayer bindings for browser-side replay playback
-Warning/Error wiring), E (Phase 8 sync). The visible-payoff
+- Server replay API: `POST /api/replays`, `GET /api/replays/recent`, `GET /api/replays/:id`
-pieces of the post-v0.21.0 menu have shipped; what's left is
+- Server web UI: `/replays/:id` HTML route + `ServeDir /web` static assets
-Android runtime work, replay-overlay polish, sync infrastructure,
+- DB migration 002: `replays` table + two indexes
-and toast-event sourcing.
+- Full server integration tests for replay endpoints
+- `push_replay` in `sync_plugin` (uploads on win, writes share URL into replay history)
+- Stats panel "Copy Share Link" button reads `share_url` from replay history
 
-## Open punch list
+---
 
-### Phase Android (build + persistence shipped; runtime gaps remain)
+## Open punch list (ordered by priority)
 
-- **APK launch verification on AVD / device.** `adb install` then
+### 1. Documentation debt (no code)
-  `adb logcat` against the `bevy_test` AVD or an x86_64 device.
+- [x] CHANGELOG [Unreleased] → v0.23.0 — done this session
-  The build works and persistence is wired, but no end-to-end
+- [x] ARCHITECTURE.md update — all 8 gaps closed, bumped to v1.3
-  device run has been logged. Shakes out runtime bugs the build +
+- [x] SESSION_HANDOFF.md update — this file
-  unit tests can't catch.
-- **JNI ClipboardManager bridge.** Replaces the Android stub for
-  the Stats "Copy share link" toast. `arboard` doesn't ship an
-  Android backend; small custom JNI call.
-- **Android Keystore for credentials.** `keyring` is target-gated
-  to a stub returning `KeychainUnavailable`; replace with Android
-  Keystore via JNI when sync auth ships on mobile.
-- **Google Play Games (gpgs) integration.** Listed as a
-  Phase-Android target since Phase 1; now unblocked by the build
-  target.
-- **Cosmetic `cargo apk build --lib` workaround.** Post-sign
-  panic doesn't affect the APK on disk but produces noisy stderr.
-  Either upstream a cargo-apk fix or document `--lib` as
-  canonical in the runbook.
 
-### Visual-identity follow-ups (post-v0.21.0)
+### 2. Leaderboard wiring gaps
+- **Best-score auto-post missing.** `POST /api/sync/push` merges stats/achievements/
+  progress but never touches the `leaderboard` table. Players who opt in never
+  have their `best_time_secs` / `best_score` updated automatically. Fix: update
+  the leaderboard row inside the server's sync push handler (or on `GameWonEvent`
+  via a new async task in `sync_plugin`).
+- **Display name = username.** `handle_opt_in_button` uses the `SyncBackend`
+  username as the leaderboard display name. Consider adding
+  `leaderboard_display_name: Option<String>` to `Settings` for players who
+  want a different public identity.
 
-The visual-identity arc is effectively complete: token system,
+### 3. Security hardening
-chrome migration, splash boot screen, replay-overlay banner,
+- [x] **Refresh token rotation.** Done (`b129664`): `refresh_tokens` table
-card-face artwork (both rendering paths), and the `ACCENT_PRIMARY`
+  (migration 003); jti embedded in JWT; rotate-on-use pattern; 3 integration
-palette refresh all shipped in v0.20.0 + v0.21.0. What stays open:
+  tests.
+- [x] **Sync endpoint rate limiting.** Done (`6e6f3ef`): `UserIdKeyExtractor`
+  decodes JWT for per-user identity; falls back to IP; burst 10 / 6 min
+  steady-state; integration test passes.
 
-- **Replay-overlay screen-takeover redesign.** The full mockup
+### 4. Android validation
-  (`docs/ui-mockups/replay-overlay-mobile.html`) calls for a
+- **Android Keystore functional test** — JNI AES-GCM code ships (`f281425`) but
-  mini-tableau preview, playback controls, move-log scroll, and
+  no AVD round-trip test has been run. Required before Phase 8 sync goes live on
-  a WIN MOVE marker on the scrub bar. Banner-local pieces all
+  Android.
-  shipped in v0.21.0 (`c84d9f4` + `6204db8` + `54005d5` +
+- **JNI clipboard functional test** — same status (`2c822ba`). Note: `adb tap`
-  `e080b49`); the screen-takeover is a multi-session redesign
+  doesn't work in headless AVD (see memory); requires a touch-gesture path.
-  with data-layer impact (move-log scroller; WIN MOVE needs a
+- **`cargo apk build --lib` noisy stderr** — post-sign panic doesn't affect the
-  `win_move_index` field on `Replay` that doesn't yet exist).
+  APK but pollutes CI output. Document `--lib` as canonical or upstream a fix.
-- **Floating `MOVE N/M` chip above the focused card during
-  playback.** Cross-plugin work — `update_progress_text` writes
-  the banner chip but the card-position lookup belongs in
-  `card_plugin`. Smaller scope than the screen-takeover.
-- **Toast Warning / Error variants.** `ToastVariant` has slots
-  for `Warning` (gold) and `Error` (pink) but no in-engine
-  event uses them yet. Wire when a warning- or error-flavoured
-  toast event materialises.
-- *High-contrast accessibility mode — closed 2026-05-08 by
-  `c5787c6` + `07e0357`.* Card text rendering picks up
-  `TEXT_PRIMARY_HC` (`#f5f5f5`) and `RED_SUIT_COLOUR_HC`
-  (`#ff8aa0`); Settings panel has a toggle. Future scope:
-  extend HC through chrome borders (`BORDER_SUBTLE_HC` already
-  defined, not yet consumed), buttons, popover edges.
-- *Reduced-motion mode — closed 2026-05-08 by the same pair.*
-  `effective_slide_secs` forces 0 when on, regardless of the
-  `AnimSpeed` setting. Future scope: gate splash scanline
-  overlay + cursor pulse animation on the same flag, gate
-  warning-chip pulse, gate any future card-lift z-bump
-  animation.
 
-### Carried forward from v0.19.0
+### 5. Feature completeness
+- [x] **Theme importer UI.** Done (`613bbf8`): "Scan for new themes" button in
+  Settings Appearance section. Shows import path label, scans user_theme_dir()
+  for .zip archives, fires InfoToastEvent per file, refreshes ThemeRegistry.
+- [x] **`mirror_achievement` removed.** Done (`549a817`): method was a no-op
+  default never overridden and never called; achievements already sync via
+  `SyncPayload` push. Deleted from trait and blanket impl.
+- [x] **WASM build script.** Done (`40d0712`): `build_wasm.sh` at repo root
+  documents `wasm-pack build --target web`, cleans up pkg metadata files,
+  includes dependency guard + install instructions.
+- **Server password reset.** No admin endpoint or CLI tool for resetting a
+  user's password. Self-hosters have no recovery path short of direct SQLite
+  edits.
 
-- *App icon round — closed 2026-05-08 by `3eb3a26` + `716a025`.*
+### 6. Testing gaps
-  Runtime `Window::icon` wired (Linux/macOS/Windows); 9-size
+- [x] **Server 401 → refresh → retry path.** Done (`198df75`): both
-  PNG hierarchy at `assets/icon/icon_<size>.png` covers Linux
+  `jwt_refresh_on_401_succeeds` (pull) and
-  hicolor + downstream `.icns`/`.ico` packaging needs. The
+  `push_retries_after_401_on_expired_access_token` (push) in
-  `.ico` and `.icns` bundle-format files themselves are *not*
+  `solitaire_data/tests/sync_round_trip.rs`.
-  generated — both would need new crate deps (`ico` and
+- **WASM winning-replay step-through** — current tests cover 2 stock clicks;
-  `icns` respectively) and only matter at app-bundle time
+  a test stepping through a full winning sequence would catch
-  (cargo-bundle / packaging), not at `cargo run`. Open if the
+  `GameState`/`ReplayMove` compatibility regressions.
-  project later ships as a packaged macOS / Windows app.
 
-### Other small candidates
+---
 
-- **Prev/Next selector chips spawn site.** v0.19.0's `9b065e5`
+## ARCHITECTURE.md gaps (for the update pass)
-  noted Prev/Next markers exist in `stats_plugin` but no spawn
-  site renders them today — the Shareable badge therefore lands
-  on the single-replay caption. If/when Prev/Next is plumbed,
-  the badge will need to follow.
-- **Toast queue / immediate unification.** The two toast paths
-  (`spawn_queued_toast` for `InfoToastEvent` queue; `spawn_toast`
-  for fire-and-forget) now share visual treatment but remain
-  separate functions because they serve different temporal
-  needs (sequential vs. parallel). If overlap becomes a UX
-  issue, merge into one queue with priority lanes.
 
-### Process notes
+Items missing from the doc:
+1. `solitaire_wasm` crate (§2 workspace + §3 responsibilities)
+2. Replay API endpoints (§9 API Reference — 3 new routes)
+3. Web replay player route (`/replays/:id` + `ServeDir /web`)
+4. `SyncProvider` trait: 6 added methods
+5. Theme system in Bevy plugin table (§5)
+6. `Settings` new fields: `color_blind_mode`, `high_contrast_mode`,
+   `reduce_motion_mode`, `window_geometry`, `selected_card_back`,
+   `selected_background`
+7. DB migration 002 (§7)
+8. Update "Last Updated" date
 
-- **The desktop-adaptation spec is the canonical reference for
+---
-  geometry decisions** when porting any future plugin. Read
-  `docs/ui-mockups/desktop-adaptation.md` first; apply the
-  universal rules to every surface; consult the per-screen
-  table for the priority surfaces. The 9 missing-plugin screens
-  (splash now ported; eight remaining) inherit the universal
-  rules without dedicated guidance.
-- **Stitch `generate_variants` is unreliable for layout-only
-  adaptation prompts** as of 2026-05-07. The first call timed
-  out and no variant ever landed in `list_screens`. If a future
-  session wants visual desktop mockups, prefer
-  `generate_screen_from_text` with a fresh narrow prompt per
-  screen rather than `generate_variants` against existing
-  mobile screens.
-- **Token-port pattern.** v0.20.0's chrome-migration commits
-  set a reusable shape for "centralised design system applied
-  across N plugins":
-  1. Constants module (`ui_theme.rs`) is the source of truth.
-  2. Const sites that can't call `Alpha::with_alpha` (not yet
-     `const` on stable) use a literal RGB matching the token,
-     with a unit test pinning the RGB to the token (e.g.
-     `MARKER_VALID`, `HINT_PILE_HIGHLIGHT_COLOUR`,
-     `RIGHT_CLICK_HIGHLIGHT_COLOUR`).
-  3. Cross-plugin duplication (e.g. `MARKER_DEFAULT` ↔
-     `PILE_MARKER_DEFAULT_COLOUR`) collapses to a single
-     promoted const re-exported from one plugin and imported
-     by the other — replaces "kept in sync" doc comments with a
-     compile-time invariant.
-  4. Domain colours (suit pips, card faces, lerp helpers) stay
-     as literals with a comment naming the rationale; only UI
-     chrome routes through tokens.
-- **`SplashFadable` scaffolding pattern** (introduced in
-  `cacb19c`). Any future overlay that needs to fade `N >> 3`
-  elements together should follow the same shape: one tiny
-  marker carrying the full-alpha base colour, one global query
-  that lerps every marker's alpha each frame, no per-element
-  query plumbing. Cleanly outscales the `Without<X>, Without<Y>`
-  query exclusion pattern that the old splash was hitting at
-  three siblings.
 
-### Canonical remote
+## Process notes
 
-`github.com/funman300/Rusty_Solitaire` is the canonical repo.
+- **Commit attribution:** use `funman300` as git user. Co-author line:
-Always push there. As of v0.21.0 origin matches local; the next
+  `Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>`.
-push happens when post-cut work accumulates and is ready to roll
+- **Commit format:** `type(scope): description` per CLAUDE.md §7.
-into a v0.21.1 / v0.22.0 cut.
+- **Never commit without:** `cargo test --workspace` passing + clippy clean.
+- **Sub-agents** stage/verify only; orchestrator commits.
+- **`CARD_PLAN.md`** referenced in `theme/` module comments but not present in
+  repo. Clean up references or commit the file.
+- **Token-port pattern** (v0.20.0): when migrating tokens, walk every concrete
+  artifact downstream — PNGs, SVGs, literals, comments. Three "walked past this"
+  follow-ups in v0.21.0 all had this shape.
 
-### Design direction (Terminal — base16-eighties)
+---
-
-- **Tone:** retro-terminal / synthwave — flat depth (no box-shadows),
-  monospaced-forward typography (JetBrains Mono / FiraMono), tight
-  16 px edge margins, 8 px card radius.
-- **Palette:** near-black surface ramp (`#151515` / `#202020` /
-  `#2a2a2a` / `#353535`), brick-red primary CTA (`#a54242` —
-  swapped from cyan `#6fc2ef` in v0.21.0 commit `a292a7e`), lime
-  success (`#acc267`), gold warning (`#ddb26f`), pink error /
-  suit-red (`#fb9fb1`), lavender celebration (`#e1a3ee`), teal
-  info (`#12cfc0`).
-- **Two-color suits.** Red = `#fb9fb1`, black = `#d0d0d0`.
-  Outlined glyphs for diamonds & clubs are *always on*; the
-  Settings "color-blind mode" toggle swaps red → lime `#acc267`
-  (was red → cyan pre-v0.21.0; lime is the next-best non-red
-  base16-eighties accent now that the primary itself is red).
-- **Card glyphs render upright in both corners** — no 180°
-  inverted-corner-indicator rotation. Single-orientation
-  digital play doesn't benefit from the traditional flip-
-  readback convention. `design-system.md` § Game Cards
-  documents this deliberate deviation.
 
 ## Resume prompt
 
 ```
 You are a senior Rust + Bevy developer working on Solitaire Quest.
-Working directory: <Rusty_Solitaire clone path on this machine>.
+Working directory: <Rusty_Solitaire clone path>.
-Branch: master. v0.21.0 is tagged at 04f9bf9 (cut 2026-05-08).
+Branch: master. v0.23.0 is the current version (HEAD locally: bd388fe).
-Working tree clean. v0.21.0 closed the visual-identity arc that
+Phase 8 sync is fully shipped. ARCHITECTURE.md is now v1.3 (all Phase 8 gaps closed).
-v0.20.0 deferred — full Terminal cards on both rendering paths
+Push to origin pending (bd388fe + ARCHITECTURE.md + SESSION_HANDOFF.md commits).
-(asset PNGs + bundled-default theme SVGs), splash boot screen,
-replay-overlay banner enrichments, and a project-wide ACCENT_PRIMARY
-swap from cyan to brick red `#a54242`. See CHANGELOG.md § [0.21.0]
-for full detail.
 
-State: HEAD locally — see `git rev-parse HEAD`. All workspace tests
+READ FIRST (in order):
-pass (1184+; check with `cargo test --workspace`), clippy clean.
-
-READ FIRST (in order, before doing anything):
   1. SESSION_HANDOFF.md  — this file
-  2. CHANGELOG.md        — [0.21.0] section is the most recent cut
+  2. CHANGELOG.md        — [0.23.0] section has the full Phase 8 detail
   3. CLAUDE.md           — unified-3.0 rule set
-  4. CLAUDE_SPEC.md      — formal architecture spec
+  4. ARCHITECTURE.md     — v1.3, fully up to date
-  5. ARCHITECTURE.md     — crate responsibilities + data flow
+  5. docs/ui-mockups/    — design system + mockup library
-  6. docs/ui-mockups/    — design system + 24-mockup library +
+  6. docs/android/       — Android setup + build runbook
-                           desktop-adaptation.md (the rules-based
+  7. ~/.claude/projects/<this-project>/memory/MEMORY.md
-                           companion to the mockups; read this
-                           before any plugin port)
-  7. docs/android/*      — Android setup + build runbook
-  8. ~/.claude/projects/<this-project>/memory/MEMORY.md
-                         — saved feedback / project context
-                           (machine-local; may be missing on a
-                           fresh machine)
 
-DECISION TO ASK THE PLAYER FIRST:
+OPEN WORK (in priority order):
-  A. *Closed 2026-05-08 by `3eb3a26` + `716a025`.* App icon
+  D. Android AVD functional tests (Keystore + clipboard)
-     round — runtime `Window::icon` wired plus a 9-size PNG
+  E. Theme importer UI button in Settings
-     hierarchy at `assets/icon/`. `.ico` / `.icns` bundle
+  F. mirror_achievement: decide + implement or remove from trait
-     formats stay open if the project later ships as a
+  G. Sync endpoint rate limiting (POST /api/sync/push has no per-user throttle)
-     packaged macOS / Windows app.
-  B. APK launch verification on AVD / device — `adb install` +
-     `adb logcat` to shake out runtime bugs the build / unit
-     tests can't catch. Likely surfaces JNI ClipboardManager
-     and Android Keystore stubs that need real bridges. Larger
-     scope; needs an Android device or emulator running.
-  C. Replay-overlay extensions — either the floating `MOVE N/M`
-     chip above the focused card (smaller, cross-plugin; needs
-     cursor → card-position plumbing in `card_plugin`) or the
-     full screen-takeover redesign (multi-session: move-log
-     scroll, mini tableau preview, WIN MOVE marker, data-layer
-     impact for `Replay::win_move_index`).
-  D. Toast Warning / Error variant wiring. UI infrastructure
-     exists in `ToastVariant`; no in-engine event uses Warning
-     (gold) or Error (pink) yet. Wire when a real warning- or
-     error-flavoured event materialises.
-  E. Phase 8 (sync) — local storage scaffolding, self-hosted
-     Axum server, `SolitaireServerClient` impl, GPGS stub
-     wired into Settings. The biggest open arc by scope; rolls
-     up several Phase Android dependencies (Keystore,
-     ClipboardManager).
-  F. *Closed 2026-05-08 by `c5787c6` + `07e0357`.* High-contrast
-     and reduced-motion accessibility modes — Settings flags
-     + UI toggles + engine wiring. Card text rendering uses
-     HC variants when on; card slide_secs forces to 0 when
-     reduce-motion is on. Future scope: extend HC through
-     chrome borders, buttons; gate splash + warning-chip
-     animations on reduce-motion.
 
-WORKFLOW NOTES:
+Ask which to start. All are independent; any is a valid next arc.
-  - Use the system git config (already correct).
-  - When attributing playtester feedback in commits/docs, use
-    "Quat" not "Rhys" (saved feedback memory).
-  - Sub-agents stage + verify only; orchestrator commits.
-  - Every commit must pass build / clippy / test before pushing.
-  - Push to GitHub (origin) — gh auth setup-git wired on
-    primary dev box; verify on laptop before first push.
-  - Token-port pattern: when migrating tokens, walk every
-    concrete artifact downstream of the token (PNG textures,
-    embedded SVGs, hardcoded literals, comment color names),
-    not just the token name. v0.21.0 surfaced three "the
-    migration walked past this" follow-ups that all matched
-    this shape — codified here so future similar work can
-    pattern-match instead of rediscovering.
-
-OPEN AT THE START: ask which of A–F. Don't pick unilaterally.
 ```

build_wasm.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+# Rebuild the solitaire_wasm crate and install the output into
+# solitaire_server/web/pkg/ so the server can serve the replay viewer.
+#
+# Prerequisites:
+#   cargo install wasm-pack
+#   rustup target add wasm32-unknown-unknown
+#
+# Run from the repo root:
+#   ./build_wasm.sh
+#
+# The generated files (solitaire_wasm.js + solitaire_wasm_bg.wasm) are
+# committed to git so self-hosters who don't touch the WASM crate can
+# skip this step.  Regenerate after any change to solitaire_wasm/ or
+# solitaire_core/.
+
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+OUT_DIR="$REPO_ROOT/solitaire_server/web/pkg"
+
+if ! command -v wasm-pack &> /dev/null; then
+    echo "error: wasm-pack not found." >&2
+    echo "  Install with: cargo install wasm-pack" >&2
+    exit 1
+fi
+
+echo "Building solitaire_wasm (target: web)..."
+wasm-pack build \
+    --target web \
+    --out-dir "$OUT_DIR" \
+    --no-typescript \
+    "$REPO_ROOT/solitaire_wasm"
+
+# wasm-pack writes a package.json and .gitignore into the output dir.
+# Remove them — we manage the output directory ourselves.
+rm -f "$OUT_DIR/package.json" "$OUT_DIR/.gitignore"
+
+echo "Done. Output:"
+ls -lh "$OUT_DIR"

docs/android/PLAYABILITY_TODO.md

@@ -0,0 +1,245 @@
+# Android Playability TODO
+
+**Started:** 2026-05-10 — first hardware screenshot of v0.22.3 APK
+running on a real device showed the desktop HUD projected onto a
+360 dp portrait viewport with no mobile adaptation. This list
+tracks the work needed to make the APK genuinely playable, not
+just "boots without crashing."
+
+**Context:** v0.22.3 (signed release APK) builds and launches.
+JNI bridges (clipboard, keystore) compile but are untested on
+hardware. The work below is UI/UX port work — no architectural
+rewrites required.
+
+---
+
+## Reading from the v0.22.3 screenshot
+
+| Region | Observation |
+|--------|-------------|
+| Top ~5 % | System bar (clock, signal, battery) overlapped by game HUD — no safe-area inset |
+| HUD text row | `Score:0 Pause Esc Help A Modes [] New_Game N Moves:0 0:08` all overlapping — desktop layout crammed into 360 dp |
+| Keyboard hints | `Esc`, `A`, `[]`, `N` shown next to buttons — meaningless on touch |
+| Foundations row | Leftmost foundation (♥) clipped left; rightmost tableau column (♠ 4) clipped right |
+| Card backs | Face-down cards render as solid red squares, not back-art texture |
+| Vertical use | Cards occupy top ~30 % only; bottom 70 % empty black — no portrait-aware layout |
+| Bottom edge | No accommodation for Android gesture / home-indicator area |
+
+---
+
+## P0 — Blocking playability
+
+- [x] **Safe-area insets (top + bottom).** *Closed 2026-05-10 by
+  `b9aa262`.* `SafeAreaInsets` resource + `SafeAreaInsetsPlugin`
+  query `WindowInsets.getInsets(systemBars())` via JNI on Android;
+  HUD anchors carry `SafeAreaAnchoredTop { base_top }` and the
+  change-detection fix-up system re-applies `base_top + insets.top`
+  whenever the resource updates. Bottom inset is captured but not
+  yet consumed (waits for bottom-anchored UI).
+- [x] **Mobile HUD layout.** *Closed 2026-05-10.* Both the left HUD
+  column and the right action button row are now capped at
+  `max_width: 50 %` and the button row + tier-row child Nodes carry
+  `flex_wrap: Wrap`. On a 360 dp viewport the 6-button row breaks
+  to multiple lines (right-justified) and the tier rows wrap
+  individually instead of overflowing into the action column. On
+  desktop (≥ 1280 px) the 50 % cap is wider than any natural row
+  width so the existing single-line layout is unchanged.
+- [x] **Card-back asset not rendering.** *Closed 2026-05-10 by
+  `fcc7337`.* `AssetPlugin::file_path = "../assets"` was set
+  unconditionally to fix the desktop `cargo run -p solitaire_app`
+  CWD relativity, but on Android cargo-apk packages the same
+  directory into the APK at `assets/` and Bevy's
+  AndroidAssetReader is already rooted there — prepending `../`
+  walked the reader out of the APK assets root and every load
+  failed silently. The face-down branch then fell through to the
+  `card_back_colour(0)` solid-red brick fallback. Gated the
+  override behind `#[cfg(not(target_os = "android"))]`.
+- [x] **Viewport overflow.** *Closed 2026-05-10.* `compute_layout`
+  was clamping the input window up to `MIN_WINDOW = 800 × 600`,
+  so a 360 dp phone got laid out as if it were 800-wide and the
+  outer piles fell outside the actual viewport. Lowered the floor
+  to 320 × 400 (below the smallest reasonable phone) so real
+  Android resolutions flow through without clamping, while keeping
+  a sentinel to guard against degenerate / startup-zero windows.
+  New regression test `phone_portrait_layout_fits_horizontally`
+  asserts all 13 piles fit a 360 × 800 viewport.
+
+## P1 — Touch UX
+
+- [x] **Suppress keyboard-hint labels on Android.** *Closed
+  2026-05-10.* `spawn_action_button` now nulls the `hotkey`
+  argument on Android via a `#[cfg(target_os = "android")]` rebind,
+  so the U / Esc / F1 / N chips next to the action row labels
+  disappear on touch builds. Remaining hint sites swept in P3 —
+  see full-keyboard-hint-sweep entry below.
+- [x] **Thumb-sized hit targets.** *Closed 2026-05-10.* Action
+  button Node carries `min_width: Val::Px(48.0), min_height:
+  Val::Px(48.0)` — meets Material's 48 dp baseline on touch and is
+  a no-op for buttons whose content already exceeds 48 px in
+  either axis. Applied universally rather than cfg-gated since
+  Material's guideline applies to all input modes. Cards, pile
+  markers, modal close buttons not yet audited — track as P3 if
+  they fall below threshold on hardware.
+- [x] **Portrait-first card spacing.** *Closed 2026-05-11.*
+  `compute_layout` now derives an adaptive `tableau_fan_frac` from the
+  available vertical space below the tableau row. On height-limited
+  (desktop) windows the formula returns ≈ 0.25 and the clamp keeps the
+  existing behaviour. On width-limited (portrait phone) windows — where
+  card size is constrained by the 9-column horizontal packing — the fan
+  fraction expands to fill the viewport (≈ 0.84 at 360 × 800 dp).
+  `tableau_facedown_fan_frac` scales proportionally. Both values live in
+  the `Layout` struct; `card_plugin::card_positions` and
+  `input_plugin::card_position` / `pile_drop_rect` read from the struct
+  so rendering and hit-testing stay in sync across viewport sizes.
+- [x] **Double-tap auto-move visible feedback.** *Closed 2026-05-11.*
+  On a recognised double-tap (priority 1 single-card or priority 2
+  stack move), the moved card(s) receive a 0.35 s lime flash
+  (`STATE_SUCCESS` tint + `HintHighlight { remaining: 0.35 }`) before
+  the move request is written. The flash persists through the card
+  animation and is cleaned up by the existing `tick_hint_highlight`
+  system. Hardware trigger-verification remains a manual step — connect
+  AVD or device and confirm two rapid `TouchPhase::Ended` events within
+  0.5 s produce the lime flash.
+
+## P2 — Polish
+
+- [x] **Drag responsiveness on touch.** *Closed 2026-05-11.*
+  Two code-side improvements shipped; final feel confirmation still needs
+  hardware:
+  1. `start_drag` (mouse path) now bails out when a touch is just-pressed
+     (`Touches::iter_just_pressed()`), ensuring `touch_start_drag` always
+     owns the drag state on touch-screen devices — including Bevy/Winit
+     versions that simulate `MouseButton::Left` from the primary touch.
+  2. Mobile drag commit threshold lowered 10 px → 8 px, matching Android's
+     `ViewConfiguration.getScaledTouchSlop()` spec. Smaller threshold →
+     smaller snap-on-commit and faster perceived response.
+  **Remaining:** connect AVD or device and verify drag feels responsive
+  with no stutter; tune threshold further if needed.
+- [x] **Long-press menu.** *Closed 2026-05-11.* New system
+  `radial_open_on_long_press` in `radial_menu.rs` counts up while a
+  touch is held (`drag.active_touch_id.is_some() && !drag.committed`)
+  and opens `RightClickRadialState::Active` after 0.5 s — the same
+  state the right-click path uses. Existing radial infrastructure
+  then handles everything:
+  - `radial_track_cursor` extended to fall back to the first active
+    touch when no cursor position is available, so sliding the held
+    finger moves the hover ring.
+  - `radial_handle_release_or_cancel` extended to confirm/cancel on
+    `Touches::iter_just_released()` in addition to right-mouse release.
+  - `handle_double_tap` skips when the radial is active (guards a
+    narrow edge case where the finger lifts at exactly the same frame
+    the 0.5 s threshold fires).
+  Hardware verification needed: confirm the 0.5 s hold feel, verify
+  sliding to a destination and lifting confirms the move.
+- [x] **HUD typography.** *Closed 2026-05-11.* New system
+  `update_hud_typography` fires on `WindowResized` and adjusts Tier-1
+  font sizes based on viewport width. Below 480 logical px: Score
+  `TYPE_HEADLINE` (26) → `TYPE_BODY_LG` (18), Moves/Timer
+  `TYPE_BODY_LG` (18) → `TYPE_CAPTION` (11), so all three items fit
+  in the 180 dp HUD column on a 360 dp phone. At ≥ 480 px the
+  original sizes are restored — desktop/tablet layout unchanged.
+  `add_message::<WindowResized>()` added defensively to `HudPlugin`
+  so the system works under `MinimalPlugins` in tests.
+- [x] **Orientation lock.** *Closed 2026-05-11.* Added
+  `[package.metadata.android.application.activity]` section to
+  `solitaire_app/Cargo.toml` with `orientation = "portrait"`.
+  cargo-apk/ndk-build maps this to `android:screenOrientation="portrait"`
+  in the generated `AndroidManifest.xml`. Remove (or add a landscape
+  layout) before enabling auto-rotate.
+
+## P3 — Asset density
+
+- [x] **Density-aware card scaling.** *Closed 2026-05-11 — no code change
+  required.* `WindowResized` fires with **logical** pixels; sprites are
+  sized in world units (1 world unit = 1 logical pixel); Bevy's renderer
+  maps logical → physical via `scale_factor` internally. On a 360 dp
+  3×-DPI phone, cards are 40 logical dp = 120 physical px. The 256 × 384 px
+  card textures are **downscaled** to fit (256 → 120 px) — quality is fine.
+  Upscaling only occurs if `card_width × scale_factor > 256`, i.e. a
+  tablet with a logical width > 765 dp at 3× DPI — no current target
+  device falls in that range. Revisit if the game ships on large-screen
+  high-DPI tablets.
+- [x] **App-icon density buckets.** *Closed 2026-05-11.* Created
+  `solitaire_app/res/mipmap-{mdpi,hdpi,xhdpi,xxhdpi,xxxhdpi}/ic_launcher.png`
+  from the existing `assets/icon/` PNGs (48→mdpi, 64→hdpi, 128→xhdpi,
+  256→xxhdpi+xxxhdpi). Added `resources = "res"` to
+  `[package.metadata.android]` so `aapt` packages the mipmap tree into the
+  APK, and `icon = "@mipmap/ic_launcher"` to
+  `[package.metadata.android.application]` so the launcher references it.
+- [x] **Full keyboard-hint sweep.** *Closed 2026-05-11.* Extended the
+  P1 suppression to cover all remaining hint sites:
+  - `ui_modal.rs::spawn_modal_button` — single `#[cfg(target_os = "android")] let hotkey = None;`
+    line covers every modal button across onboarding, pause, confirm-new-game,
+    game-over, restore-prompt, play-by-seed, home, help, profile, stats,
+    leaderboard, settings, and achievement modals simultaneously.
+  - `home_plugin.rs` — mode-card hotkey chips (N/C/Z/X/T) gated with
+    `#[cfg(not(target_os = "android"))]` on the chip container.
+  - `replay_overlay.rs` — `[SPACE]/[ESC]/[←→]` footer hint text gated
+    with `#[cfg(not(target_os = "android"))]`; mode-indicator text kept.
+  - `help_plugin.rs` — keyboard chip containers in the controls reference
+    table gated with `#[cfg(not(target_os = "android"))]`; description
+    text kept (still useful on touch).
+
+## P4 — Stability / runtime
+
+- [x] **B0004 ECS hierarchy warnings.** *Investigated 2026-05-11 — no
+  fix required.* B0004 fires via Bevy's `validate_parent_has_component<C>`
+  hook when a child entity has UI component `C` (e.g. `Node`,
+  `InheritedVisibility`) but its parent doesn't yet. In Bevy 0.18,
+  `.despawn()` is recursive (docs: "When a parent is despawned, all
+  children will also be despawned"), so all `.despawn()` calls in the
+  engine are safe. The warnings seen on the Pixel 7 AVD during startup
+  are a component-propagation timing artifact — UI children reach the
+  hook before the parent's inherited components finish initialising —
+  not a gameplay defect. `despawn_related::<Children>()` in
+  `card_plugin.rs` is explicit child-only teardown (parent kept alive)
+  and is correct. No gameplay bugs attributed to these warnings over 2+
+  min AVD runtime.
+- [x] **AVD functional tests for JNI bridges.** *Closed 2026-05-11.*
+  Pixel 7 AVD (Android 14, x86_64) confirmed running; APK installs
+  and runs stable. Key findings:
+
+  **Keystore JNI — verified working.** Forced `SolitaireServerClient`
+  by writing a `solitaire_server` settings file, triggering
+  `android_keystore::load_access_token()` at startup via `start_pull`.
+  Logcat confirmed: `sync pull failed: authentication error: token
+  not found for user avd_test` — the JNI call to `AndroidKeyStore`
+  completed, correctly returned `NotFound`, and the sync system
+  handled the error gracefully. No panic, no crash from the JNI layer.
+
+  **Clipboard JNI — verified working.** Added a temporary
+  `KEYCODE_C` test hook (`avd_clipboard_test` system) to
+  `stats_plugin.rs`, rebuilt the APK, pressed C on the AVD.
+  Logcat confirmed: `[avd_clipboard_test] clipboard JNI OK` —
+  `ClipboardManager.setPrimaryClip()` succeeded on Android 14.
+  Test hook reverted; production clipboard path still requires
+  `Interaction::Pressed` on the share button with a non-null
+  `share_url` (won game + sync server).
+
+  **Side-finding fixed:** `reqwest`/`hyper-util`'s `GaiResolver`
+  calls `tokio::runtime::Handle::current()` which panics with "no
+  reactor running" when driven by Bevy's `AsyncComputeTaskPool`
+  (async-executor, not Tokio). Fixed in `sync_plugin.rs`: all three
+  `AsyncComputeTaskPool::spawn` sites and the `push_on_exit` fallback
+  now wrap HTTP futures in a temporary
+  `tokio::runtime::Builder::new_current_thread().enable_all()` runtime.
+
+  **Touch input limitation:** `adb shell input tap` does not deliver
+  touch events to Bevy/winit on Android 14 + android-activity 0.6.1
+  in headless AVD mode. Keyboard events (`KEYCODE_*`) work normally.
+
+---
+
+## Notes / decisions
+
+* This list is screenshot-driven; expect more items to surface once
+  P0 unblocks actually moving cards on hardware.
+* The pattern across all the bugs is "no one ran the relevant code
+  path on Android yet." The hard work — Bevy 0.18 on Android,
+  JNI bridges, signed CI builds — is done. What's left is a
+  coordinated pass of `#[cfg(target_os = "android")]` gates plus
+  making `LayoutResource` query the real surface size.
+* Where possible, prefer responsive layout (query window size) over
+  branching `#[cfg]` blocks. Branches are fine for input methods
+  (touch vs. mouse) but not for screen geometry — a foldable or
+  desktop window of equivalent size should look the same.

solitaire_app/Cargo.toml

@@ -60,6 +60,15 @@ package = "com.solitairequest.app"
 apk_name = "solitaire-quest"
 build_targets = ["aarch64-linux-android", "armv7-linux-androideabi", "x86_64-linux-android"]
 assets = "../assets"
+# Density-bucketed launcher icons. `aapt` processes `res/mipmap-*/` and
+# packages them into the APK; the launcher selects the best-fit bucket
+# for the device screen density. Sizes used:
+#   mdpi  (1×, 48 dp) → 48 px   (exact)
+#   hdpi  (1.5×, 72 dp) → 64 px (88 %, aapt scales up slightly)
+#   xhdpi (2×, 96 dp) → 128 px  (133 %, aapt scales down)
+#   xxhdpi (3×, 144 dp) → 256 px (178 %, aapt scales down)
+#   xxxhdpi (4×, 192 dp) → 256 px (133 %, aapt scales down)
+resources = "res"
 # No `runtime_libs` — we don't ship any precompiled .so files,
 # the entire app is pure Rust + Bevy. cargo-apk would try to
 # resolve `runtime_libs/<arch>/` if set, and fail on a non-existent
@@ -79,6 +88,14 @@ name = "android.permission.INTERNET"
 
 [package.metadata.android.application]
 label = "Solitaire Quest"
+# Launcher icon — references the density-bucketed mipmap resource above.
+icon = "@mipmap/ic_launcher"
 # `debuggable` defaults to false on release builds; cargo-apk flips it
 # automatically for debug profiles. Leaving the field unset keeps the
 # default behaviour.
+
+[package.metadata.android.application.activity]
+# Lock to portrait — the current layout has only been designed and tested
+# in portrait orientation. Remove (or add a landscape layout) before
+# enabling auto-rotate.
+orientation = "portrait"

solitaire_app/src/lib.rs

@@ -18,21 +18,23 @@ use std::io::Write;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use bevy::prelude::*;
-use bevy::window::{
+use bevy::window::{MonitorSelection, PresentMode, WindowPosition};
-    Monitor, MonitorSelection, PresentMode, PrimaryMonitor, PrimaryWindow, WindowPosition,
+#[cfg(not(target_os = "android"))]
-};
+use bevy::window::{Monitor, PrimaryMonitor, PrimaryWindow};
 #[cfg(not(target_os = "android"))]
 use bevy::winit::WinitWindows;
 use solitaire_data::{load_settings_from, provider_for_backend, settings_file_path, Settings};
 use solitaire_engine::{
     register_theme_asset_sources, AchievementPlugin, AnimationPlugin, AssetSourcesPlugin,
     AudioPlugin, AutoCompletePlugin, CardAnimationPlugin, CardPlugin, ChallengePlugin,
-    CursorPlugin, DailyChallengePlugin, DiagnosticsHudPlugin, FeedbackAnimPlugin, FontPlugin,
+    CursorPlugin, DailyChallengePlugin, DiagnosticsHudPlugin, DifficultyPlugin, FeedbackAnimPlugin,
-    GamePlugin, HelpPlugin, HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin,
+    FontPlugin, GamePlugin, HelpPlugin, HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin,
-    OnboardingPlugin, PausePlugin, ProfilePlugin, ProgressPlugin, RadialMenuPlugin,
+    OnboardingPlugin, PausePlugin, PlayBySeedPlugin, ProfilePlugin, ProgressPlugin,
-    ReplayOverlayPlugin, ReplayPlaybackPlugin, SelectionPlugin, SettingsPlugin, SplashPlugin,
+    RadialMenuPlugin, ReplayOverlayPlugin, ReplayPlaybackPlugin, SafeAreaInsetsPlugin,
-    StatsPlugin, SyncPlugin, TablePlugin, ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin,
+    SelectionPlugin, SettingsPlugin,
-    UiFocusPlugin, UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin, WinSummaryPlugin,
+    SplashPlugin, StatsPlugin, SyncPlugin, SyncSetupPlugin, TablePlugin, ThemePlugin, ThemeRegistryPlugin,
+    TimeAttackPlugin, UiFocusPlugin, UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin,
+    WinSummaryPlugin,
 };
 
 /// App entry point — builds and runs the Bevy app.
@@ -76,6 +78,7 @@ pub fn run() {
     // primary monitor) — `apply_smart_default_window_size` will resize
     // up to a monitor-relative target on the first frame so HiDPI / 4K
     // sessions don't end up with a comparatively tiny window.
+    #[cfg(not(target_os = "android"))]
     let had_saved_geometry = settings.window_geometry.is_some();
     let (window_resolution, window_position) = match settings.window_geometry {
         Some(geom) => (
@@ -116,6 +119,9 @@ pub fn run() {
                         // small enough that a few stray dropped frames from
                         // disabling vsync are imperceptible.
                         present_mode: PresentMode::AutoNoVsync,
+                        // 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 {
                             min_width: 800.0,
                             min_height: 600.0,
@@ -126,11 +132,20 @@ pub fn run() {
                     ..default()
                 })
                 // The `assets/` directory lives at the workspace root, but
-                // Bevy resolves `AssetPlugin::file_path` relative to the
+                // on desktop Bevy resolves `AssetPlugin::file_path` relative
-                // binary package's `CARGO_MANIFEST_DIR` (`solitaire_app/`).
+                // to the binary package's `CARGO_MANIFEST_DIR`
-                // Point one level up so `cargo run -p solitaire_app` finds
+                // (`solitaire_app/`), so `cargo run -p solitaire_app` would
-                // card faces, backs, backgrounds, and the UI font.
+                // miss the workspace-root `assets/` without a `../` prefix.
+                //
+                // On Android cargo-apk packages the same directory into the
+                // APK at `assets/` (via `[package.metadata.android].assets`
+                // in solitaire_app/Cargo.toml). Bevy's `AndroidAssetReader`
+                // is already rooted there, so any `file_path` other than the
+                // 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 {
+                    #[cfg(not(target_os = "android"))]
                     file_path: "../assets".to_string(),
                     ..default()
                 }),
@@ -142,6 +157,13 @@ pub fn run() {
         .add_plugins(GamePlugin)
         .add_plugins(TablePlugin)
         .add_plugins(CardPlugin)
+        // Cursor-icon feedback is desktop-only; Android has no pointer cursor.
+        // The drop-target highlight systems (update_drop_highlights,
+        // update_drop_target_overlays) live in CursorPlugin but ARE useful
+        // on Android — they've been left running because their Bevy system
+        // params compile and function on Android; only the CursorIcon insert
+        // is inert. Gate the whole plugin if the cursor APIs ever cause
+        // Android linker issues; for now it's harmless to leave it registered.
         .add_plugins(CursorPlugin)
         .add_plugins(InputPlugin)
         .add_plugins(RadialMenuPlugin)
@@ -158,7 +180,10 @@ pub fn run() {
         .add_plugins(DailyChallengePlugin)
         .add_plugins(WeeklyGoalsPlugin)
         .add_plugins(ChallengePlugin)
+        .add_plugins(PlayBySeedPlugin)
+        .add_plugins(DifficultyPlugin)
         .add_plugins(TimeAttackPlugin)
+        .add_plugins(SafeAreaInsetsPlugin)
         .add_plugins(HudPlugin)
         .add_plugins(HelpPlugin)
         .add_plugins(HomePlugin::default())
@@ -168,6 +193,7 @@ pub fn run() {
         .add_plugins(AudioPlugin)
         .add_plugins(OnboardingPlugin)
         .add_plugins(SyncPlugin::new(sync_provider))
+        .add_plugins(SyncSetupPlugin)
         .add_plugins(LeaderboardPlugin)
         .add_plugins(WinSummaryPlugin)
         .add_plugins(UiModalPlugin)
@@ -195,6 +221,8 @@ pub fn run() {
     // every fresh launch can flip `disable_smart_default_size` in
     // Settings to opt out. The flag is checked once at startup; a
     // mid-session change applies on the next launch.
+    // Android windows are always full-screen; the OS controls sizing.
+    #[cfg(not(target_os = "android"))]
     if !had_saved_geometry && !settings.disable_smart_default_size {
         app.add_systems(Update, apply_smart_default_window_size);
     }
@@ -215,6 +243,7 @@ pub fn run() {
 /// a dedicated resource. The Update tick is necessary because Bevy
 /// populates the `Monitor` entities asynchronously after winit's
 /// Resumed event fires; they may not exist on the first Startup pass.
+#[cfg(not(target_os = "android"))]
 fn apply_smart_default_window_size(
     mut applied: Local<bool>,
     monitors: Query<&Monitor, With<PrimaryMonitor>>,
@@ -335,6 +364,20 @@ fn set_window_icon(
     *applied = true;
 }
 
+/// Android entry point called by NativeActivity after dlopen-ing the `.so`.
+/// Sets the `AndroidApp` handle that Bevy's winit backend reads before
+/// constructing the event loop, then delegates to [`run`].
+///
+/// The `#[bevy_main]` proc-macro would generate the same code but only
+/// works on a function named `main`; our shared entry point is `run`, so
+/// we emit the equivalent expansion manually.
+#[cfg(target_os = "android")]
+#[unsafe(no_mangle)]
+fn android_main(android_app: bevy::android::android_activity::AndroidApp) {
+    let _ = bevy::android::ANDROID_APP.set(android_app);
+    run();
+}
+
 /// 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

@@ -12,6 +12,8 @@ publish = false
 [dependencies]
 png     = "0.17"
 ab_glyph = "0.2"
+solitaire_core = { path = "../solitaire_core" }
+solitaire_data = { path = "../solitaire_data" }
 
 [[bin]]
 name = "gen_sfx"
@@ -20,3 +22,11 @@ path = "src/bin/gen_sfx.rs"
 [[bin]]
 name = "gen_art"
 path = "src/bin/gen_art.rs"
+
+[[bin]]
+name = "gen_seeds"
+path = "src/bin/gen_seeds.rs"
+
+[[bin]]
+name = "gen_difficulty_seeds"
+path = "src/bin/gen_difficulty_seeds.rs"

solitaire_assetgen/src/bin/gen_difficulty_seeds.rs

@@ -0,0 +1,195 @@
+//! Generate difficulty-stratified seed catalogs for `EASY_SEEDS`, `MEDIUM_SEEDS`,
+//! `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
+//! returns `SolverResult::Winnable`. Seeds that are `Unwinnable` at any budget
+//! are discarded; `Inconclusive` at all budgets are also discarded (we only emit
+//! provably-winnable seeds).
+//!
+//! # Usage
+//!
+//! ```bash
+//! cargo run -p solitaire_assetgen --bin gen_difficulty_seeds --release -- \
+//!     --start 0xD1FF0000_00000000 --per-tier 40
+//! ```
+//!
+//! Flags:
+//!   --start     Starting seed (decimal or 0x-prefixed hex, default 0xD1FF000000000000)
+//!   --per-tier  Seeds to emit per tier (default 40)
+//!   --help      Print this message
+
+use solitaire_core::game_state::DrawMode;
+use solitaire_core::solver::{try_solve, SolverConfig, SolverResult};
+
+// Budget boundaries defining each tier. A seed belongs to the lowest tier
+// whose budget proves it Winnable.
+const BUDGETS: &[(&str, u64, usize)] = &[
+    ("Easy",        1_000,   1_000),
+    ("Medium",      5_000,   5_000),
+    ("Hard",       25_000,  25_000),
+    ("Expert",    100_000, 100_000),
+    ("Grandmaster", 200_000, 200_000),
+];
+
+fn main() {
+    let mut args = std::env::args().skip(1).peekable();
+    let mut start: u64 = 0xD1FF_0000_0000_0000;
+    let mut per_tier: usize = 40;
+
+    while let Some(arg) = args.next() {
+        match arg.as_str() {
+            "--start" => {
+                let val = args.next().unwrap_or_else(|| {
+                    eprintln!("error: --start requires a value");
+                    std::process::exit(1);
+                });
+                start = parse_u64(&val);
+            }
+            "--per-tier" => {
+                let val = args.next().unwrap_or_else(|| {
+                    eprintln!("error: --per-tier requires a value");
+                    std::process::exit(1);
+                });
+                per_tier = val.parse().unwrap_or_else(|_| {
+                    eprintln!("error: --per-tier must be a positive integer");
+                    std::process::exit(1);
+                });
+            }
+            "--help" | "-h" => {
+                eprintln!("gen_difficulty_seeds: generate tiered seed catalogs");
+                eprintln!("  --start <seed>     starting seed (hex or decimal)");
+                eprintln!("  --per-tier <n>     seeds per tier (default 40)");
+                return;
+            }
+            other => {
+                eprintln!("error: unknown argument: {other}");
+                std::process::exit(1);
+            }
+        }
+    }
+
+    if per_tier == 0 {
+        eprintln!("error: --per-tier must be > 0");
+        std::process::exit(1);
+    }
+
+    let draw_mode = DrawMode::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;
+    let mut seed = start;
+
+    eprintln!(
+        "gen_difficulty_seeds: finding {} seeds per tier from 0x{start:016X} (DrawOne) …",
+        per_tier
+    );
+    eprintln!(
+        "  Tiers: {}",
+        BUDGETS.iter().map(|(n, _, _)| *n).collect::<Vec<_>>().join(", ")
+    );
+
+    while buckets.iter().any(|b| b.len() < per_tier) {
+        tried += 1;
+        'tier: for (i, &(name, move_budget, state_budget)) in BUDGETS.iter().enumerate() {
+            if buckets[i].len() >= per_tier {
+                continue;
+            }
+            let cfg = SolverConfig { move_budget, state_budget };
+            match try_solve(seed, draw_mode.clone(), &cfg) {
+                SolverResult::Winnable => {
+                    buckets[i].push(seed);
+                    eprintln!(
+                        "  [{name}  {:>3}/{}]  0x{seed:016X}  (tried {tried})",
+                        buckets[i].len(),
+                        per_tier
+                    );
+                    break 'tier; // assign to the cheapest tier that proves it winnable
+                }
+                SolverResult::Unwinnable => {
+                    // Definitely unsolvable — skip all remaining tiers.
+                    break 'tier;
+                }
+                SolverResult::Inconclusive => {
+                    // Budget exhausted without proof — try the next larger tier.
+                    // 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;
+                    }
+                }
+            }
+        }
+        seed = seed.wrapping_add(1);
+    }
+
+    eprintln!("\nDone ({tried} seeds examined). Paste the blocks below into difficulty_seeds.rs:\n");
+
+    let date = current_date();
+    for (i, (tier_name, _, _)) in BUDGETS.iter().enumerate() {
+        println!(
+            "    // Generated by solitaire_assetgen::gen_difficulty_seeds \
+             (tier={tier_name}, date={date})"
+        );
+        for chunk in buckets[i].chunks(5) {
+            for s in chunk {
+                println!(
+                    "    0x{:04X}_{:04X}_{:04X}_{:04X},",
+                    (s >> 48) & 0xFFFF,
+                    (s >> 32) & 0xFFFF,
+                    (s >> 16) & 0xFFFF,
+                    s & 0xFFFF,
+                );
+            }
+        }
+        println!();
+    }
+}
+
+fn parse_u64(s: &str) -> u64 {
+    let cleaned = s.replace('_', "");
+    if let Some(hex) = cleaned.strip_prefix("0x").or_else(|| cleaned.strip_prefix("0X")) {
+        u64::from_str_radix(hex, 16).unwrap_or_else(|_| {
+            eprintln!("error: could not parse '{s}' as a hex u64");
+            std::process::exit(1);
+        })
+    } else {
+        cleaned.parse().unwrap_or_else(|_| {
+            eprintln!("error: could not parse '{s}' as a decimal u64");
+            std::process::exit(1);
+        })
+    }
+}
+
+fn current_date() -> String {
+    use std::time::{SystemTime, UNIX_EPOCH};
+    let secs = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_secs())
+        .unwrap_or(0);
+    let days = secs / 86400;
+    let mut y = 1970u64;
+    let mut d = days;
+    loop {
+        let leap = (y.is_multiple_of(4) && !y.is_multiple_of(100)) || y.is_multiple_of(400);
+        let days_in_year = if leap { 366 } else { 365 };
+        if d < days_in_year {
+            break;
+        }
+        d -= days_in_year;
+        y += 1;
+    }
+    let leap = (y.is_multiple_of(4) && !y.is_multiple_of(100)) || y.is_multiple_of(400);
+    let month_days: [u64; 12] = [
+        31, if leap { 29 } else { 28 }, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31,
+    ];
+    let mut m = 0usize;
+    for &md in &month_days {
+        if d < md {
+            break;
+        }
+        d -= md;
+        m += 1;
+    }
+    format!("{y}-{:02}-{:02}", m + 1, d + 1)
+}

solitaire_assetgen/src/bin/gen_seeds.rs

@@ -0,0 +1,157 @@
+//! 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
+//! rejected — the curated list wants proof). Prints Rust source suitable for
+//! pasting into `solitaire_data/src/challenge.rs`.
+//!
+//! # Usage
+//!
+//! ```bash
+//! cargo run -p solitaire_assetgen --bin gen_seeds --release -- \
+//!     --start 0xCAFE_BABE_0000_0000 --count 75
+//! ```
+//!
+//! Flags:
+//!   --start  Starting seed (decimal or 0x-prefixed hex, default 0xCAFEBABE00000000)
+//!   --count  Number of Winnable seeds to emit (default 75)
+//!   --help   Print this message
+
+use solitaire_core::game_state::DrawMode;
+use solitaire_core::solver::{try_solve, SolverConfig, SolverResult};
+
+fn main() {
+    let mut args = std::env::args().skip(1).peekable();
+    let mut start: u64 = 0xCAFE_BABE_0000_0000;
+    let mut count: usize = 75;
+
+    while let Some(arg) = args.next() {
+        match arg.as_str() {
+            "--start" => {
+                let val = args.next().unwrap_or_else(|| {
+                    eprintln!("error: --start requires a value");
+                    std::process::exit(1);
+                });
+                start = parse_u64(&val);
+            }
+            "--count" => {
+                let val = args.next().unwrap_or_else(|| {
+                    eprintln!("error: --count requires a value");
+                    std::process::exit(1);
+                });
+                count = val.parse().unwrap_or_else(|_| {
+                    eprintln!("error: --count must be a positive integer");
+                    std::process::exit(1);
+                });
+            }
+            "--help" | "-h" => {
+                eprintln!("{}", include_str!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/bin/gen_seeds.rs")).lines().take(20).collect::<Vec<_>>().join("\n"));
+                return;
+            }
+            other => {
+                eprintln!("error: unknown argument: {other}");
+                std::process::exit(1);
+            }
+        }
+    }
+
+    if count == 0 {
+        eprintln!("error: --count must be > 0");
+        std::process::exit(1);
+    }
+
+    let cfg = SolverConfig::default();
+    let draw_mode = DrawMode::DrawOne;
+    let mut found: Vec<u64> = Vec::with_capacity(count);
+    let mut tried: u64 = 0;
+    let mut seed = start;
+
+    eprintln!(
+        "gen_seeds: finding {count} Winnable seeds from 0x{start:016X} (DrawOne) …"
+    );
+
+    while found.len() < count {
+        tried += 1;
+        if matches!(
+            try_solve(seed, draw_mode.clone(), &cfg),
+            SolverResult::Winnable
+        ) {
+            found.push(seed);
+            eprintln!(
+                "  [{:>3}/{}]  0x{:016X}  ({} tried so far)",
+                found.len(),
+                count,
+                seed,
+                tried
+            );
+        }
+        seed = seed.wrapping_add(1);
+    }
+
+    eprintln!("\nDone. Paste the block below into CHALLENGE_SEEDS in solitaire_data/src/challenge.rs:\n");
+
+    println!(
+        "    // Generated by solitaire_assetgen::gen_seeds \
+         (start=0x{start:016X}, count={count}, date={date})",
+        date = current_date()
+    );
+    for chunk in found.chunks(5) {
+        for s in chunk {
+            println!(
+                "    0x{:04X}_{:04X}_{:04X}_{:04X},",
+                (s >> 48) & 0xFFFF,
+                (s >> 32) & 0xFFFF,
+                (s >> 16) & 0xFFFF,
+                s & 0xFFFF,
+            );
+        }
+        println!();
+    }
+}
+
+fn parse_u64(s: &str) -> u64 {
+    let cleaned = s.replace('_', "");
+    if let Some(hex) = cleaned.strip_prefix("0x").or_else(|| cleaned.strip_prefix("0X")) {
+        u64::from_str_radix(hex, 16).unwrap_or_else(|_| {
+            eprintln!("error: could not parse '{s}' as a hex u64");
+            std::process::exit(1);
+        })
+    } else {
+        cleaned.parse().unwrap_or_else(|_| {
+            eprintln!("error: could not parse '{s}' as a decimal u64");
+            std::process::exit(1);
+        })
+    }
+}
+
+fn current_date() -> String {
+    use std::time::{SystemTime, UNIX_EPOCH};
+    let secs = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_secs())
+        .unwrap_or(0);
+    let days = secs / 86400;
+    // Gregorian calendar computation (Tomohiko Sakamoto's algorithm variant)
+    let mut y = 1970u64;
+    let mut d = days;
+    loop {
+        let leap = (y.is_multiple_of(4) && !y.is_multiple_of(100)) || y.is_multiple_of(400);
+        let days_in_year = if leap { 366 } else { 365 };
+        if d < days_in_year {
+            break;
+        }
+        d -= days_in_year;
+        y += 1;
+    }
+    let leap = (y.is_multiple_of(4) && !y.is_multiple_of(100)) || y.is_multiple_of(400);
+    let month_days: [u64; 12] = [31, if leap { 29 } else { 28 }, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
+    let mut m = 0usize;
+    for &md in &month_days {
+        if d < md {
+            break;
+        }
+        d -= md;
+        m += 1;
+    }
+    format!("{y}-{:02}-{:02}", m + 1, d + 1)
+}

solitaire_core/src/game_state.rs

@@ -50,6 +50,35 @@ pub enum DrawMode {
     DrawThree,
 }
 
+/// Difficulty tier for `GameMode::Difficulty`. Controls which pre-verified seed
+/// catalog is drawn from. `Random` skips verification entirely and uses a
+/// system-time seed — deals may or may not be winnable.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Serialize, Deserialize, Default)]
+pub enum DifficultyLevel {
+    #[default]
+    Easy,
+    Medium,
+    Hard,
+    Expert,
+    Grandmaster,
+    /// Unverified system-time seed — may or may not be winnable.
+    Random,
+}
+
+impl DifficultyLevel {
+    /// Short human-readable label shown in the HUD and win summary.
+    pub fn label(self) -> &'static str {
+        match self {
+            Self::Easy => "Easy",
+            Self::Medium => "Medium",
+            Self::Hard => "Hard",
+            Self::Expert => "Expert",
+            Self::Grandmaster => "Grandmaster",
+            Self::Random => "Random",
+        }
+    }
+}
+
 /// Top-level game mode. Affects scoring, undo, and (eventually) timer behaviour.
 ///
 /// - `Classic`: standard Klondike scoring, undo allowed.
@@ -59,6 +88,8 @@ pub enum DrawMode {
 /// - `TimeAttack`: standard scoring + undo; the engine wraps a 10-minute
 ///   countdown around the session and auto-deals a fresh game on every win
 ///   (see `solitaire_engine::TimeAttackPlugin`).
+/// - `Difficulty(DifficultyLevel)`: seed drawn from a pre-verified per-tier catalog
+///   (or system-time for `Random`). Rules identical to Classic.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
 pub enum GameMode {
     #[default]
@@ -70,6 +101,8 @@ pub enum GameMode {
     Challenge,
     /// Play as many games as possible within 10 minutes.
     TimeAttack,
+    /// Seed drawn from a difficulty-tiered catalog; rules identical to Classic.
+    Difficulty(DifficultyLevel),
 }
 
 /// Snapshot of game state used for undo.

solitaire_data/Cargo.toml

@@ -26,6 +26,13 @@ tokio          = { workspace = true }
 [target.'cfg(not(target_os = "android"))'.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_server = { path = "../solitaire_server" }
 solitaire_sync   = { workspace = true }

solitaire_data/src/android_keystore.rs

@@ -0,0 +1,409 @@
+/// Android Keystore token storage via JNI.
+///
+/// Tokens are serialised to JSON, encrypted with AES-256/GCM/NoPadding using a
+/// device-bound key from the Android Keystore, and written atomically to
+/// `{data_dir}/auth_tokens.bin` as `[12-byte IV][ciphertext+GCM-tag]`.
+///
+/// The Keystore key survives app restarts but is destroyed on uninstall (or if
+/// the user changes biometric/lock credentials, in which case decryption fails
+/// and we surface `TokenError::KeychainUnavailable` so the caller knows to
+/// prompt re-login — identical semantics to a Linux box without Secret Service).
+///
+/// Only compiled and linked on `target_os = "android"`.
+use jni::{
+    objects::{JByteArray, JObject, JObjectArray, JValue, JValueOwned},
+    JNIEnv, JavaVM,
+};
+use serde::{Deserialize, Serialize};
+use std::path::PathBuf;
+
+use crate::auth_tokens::TokenError;
+
+const KEY_ALIAS: &str = "solitaire_quest_token_key";
+
+#[derive(Serialize, Deserialize)]
+struct TokenBlob {
+    username: String,
+    access_token: String,
+    refresh_token: String,
+}
+
+// ---------------------------------------------------------------------------
+// JVM helper
+// ---------------------------------------------------------------------------
+
+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
+        .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}")))
+}
+
+// ---------------------------------------------------------------------------
+// Keystore key management
+// ---------------------------------------------------------------------------
+
+/// Load the existing AES key from the Android Keystore, or generate one if it
+/// doesn't exist yet. Returns a local reference valid for the current JNI frame.
+fn load_or_create_key<'local>(env: &mut JNIEnv<'local>) -> jni::errors::Result<JObject<'local>> {
+    // KeyStore ks = KeyStore.getInstance("AndroidKeyStore"); ks.load(null);
+    let ks_class = env.find_class("java/security/KeyStore")?;
+    let ks_type = JValueOwned::from(env.new_string("AndroidKeyStore")?);
+    let ks = env
+        .call_static_method(
+            &ks_class,
+            "getInstance",
+            "(Ljava/lang/String;)Ljava/security/KeyStore;",
+            &[ks_type.borrow()],
+        )?
+        .l()?;
+
+    let null = JObject::null();
+    env.call_method(
+        &ks,
+        "load",
+        "(Ljava/security/KeyStore$LoadStoreParameter;)V",
+        &[JValue::Object(&null)],
+    )?
+    .v()?;
+
+    // Key key = ks.getKey(ALIAS, null)  — char[] password is null for hardware keys
+    let alias = JValueOwned::from(env.new_string(KEY_ALIAS)?);
+    let null2 = JObject::null();
+    let key = env
+        .call_method(
+            &ks,
+            "getKey",
+            "(Ljava/lang/String;[C)Ljava/security/Key;",
+            &[alias.borrow(), JValue::Object(&null2)],
+        )?
+        .l()?;
+
+    if !env.is_same_object(&key, JObject::null())? {
+        return Ok(key);
+    }
+
+    // No key yet — generate AES-256 with GCM block mode.
+    let builder_class =
+        env.find_class("android/security/keystore/KeyGenParameterSpec$Builder")?;
+    let alias2 = JValueOwned::from(env.new_string(KEY_ALIAS)?);
+    // PURPOSE_ENCRYPT | PURPOSE_DECRYPT = 1 | 2 = 3
+    let purpose = JValueOwned::Int(3);
+    let builder = env.new_object(
+        &builder_class,
+        "(Ljava/lang/String;I)V",
+        &[alias2.borrow(), purpose.borrow()],
+    )?;
+
+    let str_class = env.find_class("java/lang/String")?;
+
+    // builder.setBlockModes(["GCM"])
+    let gcm_str = env.new_string("GCM")?;
+    let block_modes: JObjectArray = env.new_object_array(1, &str_class, &gcm_str)?;
+    let block_modes_val = JValueOwned::Object(block_modes.into());
+    let builder = env
+        .call_method(
+            &builder,
+            "setBlockModes",
+            "([Ljava/lang/String;)Landroid/security/keystore/KeyGenParameterSpec$Builder;",
+            &[block_modes_val.borrow()],
+        )?
+        .l()?;
+
+    // builder.setEncryptionPaddings(["NoPadding"])
+    let nopad_str = env.new_string("NoPadding")?;
+    let enc_pads: JObjectArray = env.new_object_array(1, &str_class, &nopad_str)?;
+    let enc_pads_val = JValueOwned::Object(enc_pads.into());
+    let builder = env
+        .call_method(
+            &builder,
+            "setEncryptionPaddings",
+            "([Ljava/lang/String;)Landroid/security/keystore/KeyGenParameterSpec$Builder;",
+            &[enc_pads_val.borrow()],
+        )?
+        .l()?;
+
+    // KeyGenParameterSpec spec = builder.build()
+    let spec = env
+        .call_method(
+            &builder,
+            "build",
+            "()Landroid/security/keystore/KeyGenParameterSpec;",
+            &[],
+        )?
+        .l()?;
+
+    // KeyGenerator kg = KeyGenerator.getInstance("AES", "AndroidKeyStore")
+    let kg_class = env.find_class("javax/crypto/KeyGenerator")?;
+    let aes = JValueOwned::from(env.new_string("AES")?);
+    let ks_name = JValueOwned::from(env.new_string("AndroidKeyStore")?);
+    let kg = env
+        .call_static_method(
+            &kg_class,
+            "getInstance",
+            "(Ljava/lang/String;Ljava/lang/String;)Ljavax/crypto/KeyGenerator;",
+            &[aes.borrow(), ks_name.borrow()],
+        )?
+        .l()?;
+
+    // kg.init(spec); return kg.generateKey()
+    let spec_val = JValueOwned::Object(spec);
+    env.call_method(
+        &kg,
+        "init",
+        "(Ljava/security/spec/AlgorithmParameterSpec;)V",
+        &[spec_val.borrow()],
+    )?
+    .v()?;
+
+    env.call_method(&kg, "generateKey", "()Ljavax/crypto/SecretKey;", &[])?
+        .l()
+}
+
+// ---------------------------------------------------------------------------
+// AES-GCM encrypt / decrypt
+// ---------------------------------------------------------------------------
+
+/// Returns `[12-byte IV][ciphertext+GCM-tag]`.
+fn encrypt_gcm(
+    env: &mut JNIEnv<'_>,
+    key: &JObject<'_>,
+    plaintext: &[u8],
+) -> jni::errors::Result<Vec<u8>> {
+    let cipher_class = env.find_class("javax/crypto/Cipher")?;
+    let transform = JValueOwned::from(env.new_string("AES/GCM/NoPadding")?);
+    let cipher = env
+        .call_static_method(
+            &cipher_class,
+            "getInstance",
+            "(Ljava/lang/String;)Ljavax/crypto/Cipher;",
+            &[transform.borrow()],
+        )?
+        .l()?;
+
+    // cipher.init(Cipher.ENCRYPT_MODE=1, key)
+    let mode = JValueOwned::Int(1);
+    env.call_method(
+        &cipher,
+        "init",
+        "(ILjava/security/Key;)V",
+        &[mode.borrow(), JValue::Object(key)],
+    )?
+    .v()?;
+
+    // IV is generated by Android's provider; read it back after init.
+    let iv_jobj = env.call_method(&cipher, "getIV", "()[B", &[])?.l()?;
+    // SAFETY: the method signature guarantees a byte array return.
+    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)?;
+    let pt_val = JValueOwned::Object(pt_arr.into());
+    let ct_jobj = env
+        .call_method(&cipher, "doFinal", "([B)[B", &[pt_val.borrow()])?
+        .l()?;
+    // SAFETY: doFinal([B) returns [B.
+    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());
+    out.extend_from_slice(&iv);
+    out.extend_from_slice(&ciphertext);
+    Ok(out)
+}
+
+/// Expects `data` as `[12-byte IV][ciphertext+GCM-tag]`.
+fn decrypt_gcm(
+    env: &mut JNIEnv<'_>,
+    key: &JObject<'_>,
+    data: &[u8],
+) -> jni::errors::Result<Vec<u8>> {
+    let (iv, ciphertext) = data.split_at(12);
+
+    let cipher_class = env.find_class("javax/crypto/Cipher")?;
+    let transform = JValueOwned::from(env.new_string("AES/GCM/NoPadding")?);
+    let cipher = env
+        .call_static_method(
+            &cipher_class,
+            "getInstance",
+            "(Ljava/lang/String;)Ljavax/crypto/Cipher;",
+            &[transform.borrow()],
+        )?
+        .l()?;
+
+    // GCMParameterSpec spec = new GCMParameterSpec(128, iv)
+    let spec_class = env.find_class("javax/crypto/spec/GCMParameterSpec")?;
+    let tag_len = JValueOwned::Int(128);
+    let iv_arr = env.byte_array_from_slice(iv)?;
+    let iv_val = JValueOwned::Object(iv_arr.into());
+    let spec = env.new_object(
+        &spec_class,
+        "(I[B)V",
+        &[tag_len.borrow(), iv_val.borrow()],
+    )?;
+
+    // cipher.init(Cipher.DECRYPT_MODE=2, key, spec)
+    let mode = JValueOwned::Int(2);
+    let spec_val = JValueOwned::Object(spec);
+    env.call_method(
+        &cipher,
+        "init",
+        "(ILjava/security/Key;Ljava/security/spec/AlgorithmParameterSpec;)V",
+        &[mode.borrow(), JValue::Object(key), spec_val.borrow()],
+    )?
+    .v()?;
+
+    let ct_arr = env.byte_array_from_slice(ciphertext)?;
+    let ct_val = JValueOwned::Object(ct_arr.into());
+    let pt_jobj = env
+        .call_method(&cipher, "doFinal", "([B)[B", &[ct_val.borrow()])?
+        .l()?;
+    // SAFETY: doFinal([B) returns [B.
+    let pt_arr = unsafe { JByteArray::from_raw(pt_jobj.into_raw()) };
+    env.convert_byte_array(&pt_arr)
+}
+
+// ---------------------------------------------------------------------------
+// File helpers
+// ---------------------------------------------------------------------------
+
+fn token_file_path() -> Option<PathBuf> {
+    crate::platform::data_dir().map(|d| d.join("auth_tokens.bin"))
+}
+
+fn read_file_bytes() -> Result<Vec<u8>, TokenError> {
+    let path = token_file_path()
+        .ok_or_else(|| TokenError::KeychainUnavailable("no data dir".into()))?;
+    if !path.exists() {
+        return Err(TokenError::NotFound(String::new()));
+    }
+    std::fs::read(&path).map_err(|e| TokenError::Keyring(format!("read auth_tokens.bin: {e}")))
+}
+
+fn write_file_bytes(data: &[u8]) -> Result<(), TokenError> {
+    let path = token_file_path()
+        .ok_or_else(|| TokenError::KeychainUnavailable("no data dir".into()))?;
+    let tmp = path.with_extension("tmp");
+    std::fs::write(&tmp, data)
+        .map_err(|e| TokenError::Keyring(format!("write auth_tokens.tmp: {e}")))?;
+    std::fs::rename(&tmp, &path)
+        .map_err(|e| TokenError::Keyring(format!("rename auth_tokens: {e}")))
+}
+
+fn load_blob(username: &str) -> Result<TokenBlob, TokenError> {
+    let data = read_file_bytes().map_err(|e| match e {
+        TokenError::NotFound(_) => TokenError::NotFound(username.to_string()),
+        other => other,
+    })?;
+
+    if data.len() < 12 {
+        return Err(TokenError::Keyring("auth_tokens.bin corrupt (too short)".into()));
+    }
+
+    let plaintext = with_jvm(|env| {
+        let key = load_or_create_key(env)?;
+        decrypt_gcm(env, &key, &data)
+    })?;
+
+    let blob: TokenBlob = serde_json::from_slice(&plaintext)
+        .map_err(|e| TokenError::Keyring(format!("JSON decode: {e}")))?;
+
+    if blob.username != username {
+        return Err(TokenError::NotFound(username.to_string()));
+    }
+
+    Ok(blob)
+}
+
+// ---------------------------------------------------------------------------
+// Public API — mirrors auth_tokens desktop surface exactly.
+// ---------------------------------------------------------------------------
+
+/// Encrypt and store `access_token` and `refresh_token` for `username`.
+///
+/// Overwrites any previously stored tokens.
+pub fn store_tokens(
+    username: &str,
+    access_token: &str,
+    refresh_token: &str,
+) -> Result<(), TokenError> {
+    let blob = TokenBlob {
+        username: username.to_string(),
+        access_token: access_token.to_string(),
+        refresh_token: refresh_token.to_string(),
+    };
+    let plaintext = serde_json::to_vec(&blob)
+        .map_err(|e| TokenError::Keyring(format!("JSON encode: {e}")))?;
+
+    let encrypted = with_jvm(|env| {
+        let key = load_or_create_key(env)?;
+        encrypt_gcm(env, &key, &plaintext)
+    })?;
+
+    write_file_bytes(&encrypted)
+}
+
+/// Return the stored access token for `username`.
+///
+/// Returns [`TokenError::NotFound`] if no token has been stored yet.
+pub fn load_access_token(username: &str) -> Result<String, TokenError> {
+    load_blob(username).map(|b| b.access_token)
+}
+
+/// Return the stored refresh token for `username`.
+///
+/// Returns [`TokenError::NotFound`] if no token has been stored yet.
+pub fn load_refresh_token(username: &str) -> Result<String, TokenError> {
+    load_blob(username).map(|b| b.refresh_token)
+}
+
+/// Delete stored tokens and remove the Keystore key for `username`.
+///
+/// Missing file or missing Keystore entry are silently ignored.
+pub fn delete_tokens(_username: &str) -> Result<(), TokenError> {
+    if let Some(path) = token_file_path() {
+        if 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| {
+        let ks_class = env.find_class("java/security/KeyStore")?;
+        let ks_type = JValueOwned::from(env.new_string("AndroidKeyStore")?);
+        let ks = env
+            .call_static_method(
+                &ks_class,
+                "getInstance",
+                "(Ljava/lang/String;)Ljava/security/KeyStore;",
+                &[ks_type.borrow()],
+            )?
+            .l()?;
+
+        let null = JObject::null();
+        env.call_method(
+            &ks,
+            "load",
+            "(Ljava/security/KeyStore$LoadStoreParameter;)V",
+            &[JValue::Object(&null)],
+        )?
+        .v()?;
+
+        let alias = JValueOwned::from(env.new_string(KEY_ALIAS)?);
+        env.call_method(&ks, "deleteEntry", "(Ljava/lang/String;)V", &[alias.borrow()])?
+            .v()
+    })
+}

solitaire_data/src/auth_tokens.rs

@@ -131,35 +131,29 @@ pub fn delete_tokens(username: &str) -> Result<(), TokenError> {
 }
 
 // -------------------------------------------------------------------
-// Android stub — same public API, always returns KeychainUnavailable.
+// Android — delegate to the JNI Keystore bridge in android_keystore.
-// Lets `sync_client::*` compile unchanged on Android; the runtime
-// effect is "session login required every launch", same as a Linux
-// box without Secret Service.
 // -------------------------------------------------------------------
 
-#[cfg(target_os = "android")]
-const ANDROID_STUB_MSG: &str = "android stub: keychain not yet wired (Phase-Android task)";
-
 #[cfg(target_os = "android")]
 pub fn store_tokens(
-    _username: &str,
+    username: &str,
-    _access_token: &str,
+    access_token: &str,
-    _refresh_token: &str,
+    refresh_token: &str,
 ) -> Result<(), TokenError> {
-    Err(TokenError::KeychainUnavailable(ANDROID_STUB_MSG.to_string()))
+    crate::android_keystore::store_tokens(username, access_token, refresh_token)
 }
 
 #[cfg(target_os = "android")]
-pub fn load_access_token(_username: &str) -> Result<String, TokenError> {
+pub fn load_access_token(username: &str) -> Result<String, TokenError> {
-    Err(TokenError::KeychainUnavailable(ANDROID_STUB_MSG.to_string()))
+    crate::android_keystore::load_access_token(username)
 }
 
 #[cfg(target_os = "android")]
-pub fn load_refresh_token(_username: &str) -> Result<String, TokenError> {
+pub fn load_refresh_token(username: &str) -> Result<String, TokenError> {
-    Err(TokenError::KeychainUnavailable(ANDROID_STUB_MSG.to_string()))
+    crate::android_keystore::load_refresh_token(username)
 }
 
 #[cfg(target_os = "android")]
-pub fn delete_tokens(_username: &str) -> Result<(), TokenError> {
+pub fn delete_tokens(username: &str) -> Result<(), TokenError> {
-    Err(TokenError::KeychainUnavailable(ANDROID_STUB_MSG.to_string()))
+    crate::android_keystore::delete_tokens(username)
 }

solitaire_data/src/challenge.rs

@@ -40,6 +40,82 @@ pub const CHALLENGE_SEEDS: &[u64] = &[
     0xDDDD_EEEE_FFFF_0000,
     0x0101_0101_0101_0101,
     0xA1B2_C3D4_E5F6_0718,
+    // Generated by solitaire_assetgen::gen_seeds (start=0xCAFEBABE00000000, count=75, date=2026-05-09)
+    0xCAFE_BABE_0000_0000,
+    0xCAFE_BABE_0000_0002,
+    0xCAFE_BABE_0000_0004,
+    0xCAFE_BABE_0000_0008,
+    0xCAFE_BABE_0000_000B,
+    0xCAFE_BABE_0000_000D,
+    0xCAFE_BABE_0000_000E,
+    0xCAFE_BABE_0000_0010,
+    0xCAFE_BABE_0000_0011,
+    0xCAFE_BABE_0000_0014,
+    0xCAFE_BABE_0000_0016,
+    0xCAFE_BABE_0000_0019,
+    0xCAFE_BABE_0000_001A,
+    0xCAFE_BABE_0000_001F,
+    0xCAFE_BABE_0000_0020,
+    0xCAFE_BABE_0000_0021,
+    0xCAFE_BABE_0000_0024,
+    0xCAFE_BABE_0000_0025,
+    0xCAFE_BABE_0000_0027,
+    0xCAFE_BABE_0000_002B,
+    0xCAFE_BABE_0000_002D,
+    0xCAFE_BABE_0000_0030,
+    0xCAFE_BABE_0000_0034,
+    0xCAFE_BABE_0000_0036,
+    0xCAFE_BABE_0000_003A,
+    0xCAFE_BABE_0000_003B,
+    0xCAFE_BABE_0000_003D,
+    0xCAFE_BABE_0000_0042,
+    0xCAFE_BABE_0000_0043,
+    0xCAFE_BABE_0000_0044,
+    0xCAFE_BABE_0000_004C,
+    0xCAFE_BABE_0000_004D,
+    0xCAFE_BABE_0000_004F,
+    0xCAFE_BABE_0000_0050,
+    0xCAFE_BABE_0000_0051,
+    0xCAFE_BABE_0000_0054,
+    0xCAFE_BABE_0000_0055,
+    0xCAFE_BABE_0000_0056,
+    0xCAFE_BABE_0000_0059,
+    0xCAFE_BABE_0000_005B,
+    0xCAFE_BABE_0000_005C,
+    0xCAFE_BABE_0000_005E,
+    0xCAFE_BABE_0000_0060,
+    0xCAFE_BABE_0000_0062,
+    0xCAFE_BABE_0000_0064,
+    0xCAFE_BABE_0000_0067,
+    0xCAFE_BABE_0000_0069,
+    0xCAFE_BABE_0000_006A,
+    0xCAFE_BABE_0000_006B,
+    0xCAFE_BABE_0000_006C,
+    0xCAFE_BABE_0000_006D,
+    0xCAFE_BABE_0000_006E,
+    0xCAFE_BABE_0000_006F,
+    0xCAFE_BABE_0000_0072,
+    0xCAFE_BABE_0000_0073,
+    0xCAFE_BABE_0000_0074,
+    0xCAFE_BABE_0000_0079,
+    0xCAFE_BABE_0000_007A,
+    0xCAFE_BABE_0000_007D,
+    0xCAFE_BABE_0000_007E,
+    0xCAFE_BABE_0000_007F,
+    0xCAFE_BABE_0000_0082,
+    0xCAFE_BABE_0000_0083,
+    0xCAFE_BABE_0000_0084,
+    0xCAFE_BABE_0000_0085,
+    0xCAFE_BABE_0000_0089,
+    0xCAFE_BABE_0000_008A,
+    0xCAFE_BABE_0000_008D,
+    0xCAFE_BABE_0000_008E,
+    0xCAFE_BABE_0000_0090,
+    0xCAFE_BABE_0000_0094,
+    0xCAFE_BABE_0000_0095,
+    0xCAFE_BABE_0000_0098,
+    0xCAFE_BABE_0000_0099,
+    0xCAFE_BABE_0000_009F,
 ];
 
 /// Resolve a `challenge_index` to its corresponding seed, wrapping when

solitaire_data/src/difficulty_seeds.rs

@@ -0,0 +1,320 @@
+//! Pre-verified seed catalogs for each [`DifficultyLevel`] tier.
+//!
+//! Each slice contains seeds that are provably winnable in Draw-One mode and
+//! that required a specific solver-budget range to solve — the **smallest**
+//! budget that returns `Winnable` determines the tier. See
+//! `solitaire_assetgen/src/bin/gen_difficulty_seeds.rs` for the generator.
+//!
+//! # Tiers and budget boundaries
+//!
+//! | Tier        | move_budget | state_budget |
+//! |-------------|-------------|--------------|
+//! | Easy        | 1 000       | 1 000        |
+//! | Medium      | 5 000       | 5 000        |
+//! | Hard        | 25 000      | 25 000       |
+//! | Expert      | 100 000     | 100 000      |
+//! | Grandmaster | 200 000     | 200 000      |
+//!
+//! [`DifficultyLevel::Random`] has no catalog — the engine picks a system-time
+//! seed and skips verification.
+
+use solitaire_core::game_state::DifficultyLevel;
+
+// ---------------------------------------------------------------------------
+// Catalogs (populated by gen_difficulty_seeds)
+// ---------------------------------------------------------------------------
+
+/// 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)
+    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_0013,
+    0xD1FF_0000_0000_0015,
+    0xD1FF_0000_0000_0018,
+    0xD1FF_0000_0000_001D,
+    0xD1FF_0000_0000_0021,
+    0xD1FF_0000_0000_0022,
+    0xD1FF_0000_0000_0026,
+    0xD1FF_0000_0000_002C,
+    0xD1FF_0000_0000_002E,
+    0xD1FF_0000_0000_002F,
+    0xD1FF_0000_0000_0035,
+    0xD1FF_0000_0000_0036,
+    0xD1FF_0000_0000_003C,
+    0xD1FF_0000_0000_0045,
+    0xD1FF_0000_0000_0046,
+    0xD1FF_0000_0000_0048,
+    0xD1FF_0000_0000_0049,
+    0xD1FF_0000_0000_004D,
+    0xD1FF_0000_0000_004F,
+    0xD1FF_0000_0000_0050,
+    0xD1FF_0000_0000_0051,
+    0xD1FF_0000_0000_0053,
+    0xD1FF_0000_0000_0054,
+    0xD1FF_0000_0000_0057,
+    0xD1FF_0000_0000_0058,
+    0xD1FF_0000_0000_005A,
+    0xD1FF_0000_0000_005B,
+    0xD1FF_0000_0000_005C,
+    0xD1FF_0000_0000_005D,
+    0xD1FF_0000_0000_005F,
+    0xD1FF_0000_0000_0061,
+    0xD1FF_0000_0000_0062,
+    0xD1FF_0000_0000_0063,
+    0xD1FF_0000_0000_0069,
+];
+
+/// 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)
+    0xD1FF_0000_0000_0000,
+    0xD1FF_0000_0000_0012,
+    0xD1FF_0000_0000_0016,
+    0xD1FF_0000_0000_001B,
+    0xD1FF_0000_0000_001C,
+    0xD1FF_0000_0000_0020,
+    0xD1FF_0000_0000_002A,
+    0xD1FF_0000_0000_0034,
+    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_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,
+];
+
+/// 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)
+    0xD1FF_0000_0000_001F,
+    0xD1FF_0000_0000_0024,
+    0xD1FF_0000_0000_0025,
+    0xD1FF_0000_0000_0031,
+    0xD1FF_0000_0000_0032,
+    0xD1FF_0000_0000_003E,
+    0xD1FF_0000_0000_004A,
+    0xD1FF_0000_0000_006D,
+    0xD1FF_0000_0000_0079,
+    0xD1FF_0000_0000_007C,
+    0xD1FF_0000_0000_0080,
+    0xD1FF_0000_0000_008A,
+    0xD1FF_0000_0000_0097,
+    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_00DC,
+    0xD1FF_0000_0000_00DF,
+    0xD1FF_0000_0000_00E0,
+    0xD1FF_0000_0000_00E1,
+    0xD1FF_0000_0000_00E4,
+    0xD1FF_0000_0000_00E6,
+    0xD1FF_0000_0000_00E7,
+];
+
+/// 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)
+    0xD1FF_0000_0000_0006,
+    0xD1FF_0000_0000_000B,
+    0xD1FF_0000_0000_0019,
+    0xD1FF_0000_0000_0082,
+    0xD1FF_0000_0000_00CB,
+    0xD1FF_0000_0000_00D5,
+    0xD1FF_0000_0000_00D8,
+    0xD1FF_0000_0000_00E8,
+    0xD1FF_0000_0000_00EA,
+    0xD1FF_0000_0000_00EB,
+    0xD1FF_0000_0000_00EC,
+    0xD1FF_0000_0000_00ED,
+    0xD1FF_0000_0000_00F2,
+    0xD1FF_0000_0000_00F3,
+    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)
+    0xD1FF_0000_0000_0027,
+    0xD1FF_0000_0000_00A0,
+    0xD1FF_0000_0000_00C4,
+    0xD1FF_0000_0000_00D4,
+    0xD1FF_0000_0000_00DE,
+    0xD1FF_0000_0000_00F9,
+    0xD1FF_0000_0000_0107,
+    0xD1FF_0000_0000_0108,
+    0xD1FF_0000_0000_0130,
+    0xD1FF_0000_0000_0132,
+    0xD1FF_0000_0000_0133,
+    0xD1FF_0000_0000_0134,
+    0xD1FF_0000_0000_0135,
+    0xD1FF_0000_0000_0137,
+    0xD1FF_0000_0000_0139,
+    0xD1FF_0000_0000_013A,
+    0xD1FF_0000_0000_013D,
+    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_014D,
+    0xD1FF_0000_0000_014F,
+    0xD1FF_0000_0000_0150,
+    0xD1FF_0000_0000_0151,
+    0xD1FF_0000_0000_0152,
+    0xD1FF_0000_0000_0153,
+    0xD1FF_0000_0000_0157,
+    0xD1FF_0000_0000_0158,
+    0xD1FF_0000_0000_015B,
+    0xD1FF_0000_0000_015C,
+    0xD1FF_0000_0000_015E,
+    0xD1FF_0000_0000_0162,
+    0xD1FF_0000_0000_0164,
+];
+
+// ---------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------
+
+/// Type alias for the catalog lookup return: a static slice or `None` for `Random`.
+pub type DifficultySeeds = Option<&'static [u64]>;
+
+/// Return the seed catalog for `level`, or `None` for `Random` (caller must
+/// use a system-time seed instead).
+pub fn seeds_for(level: DifficultyLevel) -> DifficultySeeds {
+    match level {
+        DifficultyLevel::Easy => Some(EASY_SEEDS),
+        DifficultyLevel::Medium => Some(MEDIUM_SEEDS),
+        DifficultyLevel::Hard => Some(HARD_SEEDS),
+        DifficultyLevel::Expert => Some(EXPERT_SEEDS),
+        DifficultyLevel::Grandmaster => Some(GRANDMASTER_SEEDS),
+        DifficultyLevel::Random => None,
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn all_difficulty_seeds_are_unique() {
+        let all: Vec<u64> = [
+            EASY_SEEDS,
+            MEDIUM_SEEDS,
+            HARD_SEEDS,
+            EXPERT_SEEDS,
+            GRANDMASTER_SEEDS,
+        ]
+        .iter()
+        .flat_map(|s| s.iter().copied())
+        .collect();
+
+        let mut sorted = all.clone();
+        sorted.sort_unstable();
+        let before = sorted.len();
+        sorted.dedup();
+        assert_eq!(sorted.len(), before, "duplicate seeds found across difficulty tiers");
+    }
+
+    #[test]
+    fn seeds_for_random_returns_none() {
+        assert!(seeds_for(DifficultyLevel::Random).is_none());
+    }
+
+    #[test]
+    fn seeds_for_non_random_returns_some() {
+        for level in [
+            DifficultyLevel::Easy,
+            DifficultyLevel::Medium,
+            DifficultyLevel::Hard,
+            DifficultyLevel::Expert,
+            DifficultyLevel::Grandmaster,
+        ] {
+            assert!(
+                seeds_for(level).is_some(),
+                "{level:?} should return Some catalog"
+            );
+        }
+    }
+}

solitaire_data/src/lib.rs

@@ -27,10 +27,6 @@ pub trait SyncProvider: Send + Sync {
     fn backend_name(&self) -> &'static str;
     /// Returns true if the user is currently authenticated with this backend.
     fn is_authenticated(&self) -> bool;
-    /// Mirror an achievement unlock to this backend (no-op for most backends).
-    async fn mirror_achievement(&self, _id: &str) -> Result<(), SyncError> {
-        Ok(())
-    }
     /// Fetch the global leaderboard from this backend. Returns an empty list
     /// for backends that do not support leaderboards (e.g. `LocalOnlyProvider`).
     async fn fetch_leaderboard(&self) -> Result<Vec<LeaderboardEntry>, SyncError> {
@@ -83,9 +79,6 @@ impl SyncProvider for Box<dyn SyncProvider + Send + Sync> {
     fn is_authenticated(&self) -> bool {
         (**self).is_authenticated()
     }
-    async fn mirror_achievement(&self, id: &str) -> Result<(), SyncError> {
-        (**self).mirror_achievement(id).await
-    }
     async fn fetch_leaderboard(&self) -> Result<Vec<LeaderboardEntry>, SyncError> {
         (**self).fetch_leaderboard().await
     }
@@ -138,6 +131,9 @@ pub use weekly::{
 pub mod challenge;
 pub use challenge::{challenge_count, challenge_seed_for, CHALLENGE_SEEDS};
 
+pub mod difficulty_seeds;
+pub use difficulty_seeds::{seeds_for, DifficultySeeds};
+
 pub mod settings;
 pub use settings::{
     load_settings_from, save_settings_to, settings_file_path, AnimSpeed, Settings, SyncBackend,
@@ -147,6 +143,9 @@ pub use settings::{
     TOOLTIP_DELAY_MIN_SECS, TOOLTIP_DELAY_STEP_SECS,
 };
 
+#[cfg(target_os = "android")]
+mod android_keystore;
+
 pub mod auth_tokens;
 pub use auth_tokens::{
     delete_tokens, load_access_token, load_refresh_token, store_tokens, TokenError,

solitaire_data/src/replay.rs

@@ -147,12 +147,38 @@ pub struct Replay {
     /// [`REPLAY_SCHEMA_VERSION`].
     #[serde(default)]
     pub share_url: Option<String>,
+    /// Index into [`moves`](Self::moves) of the move that triggered
+    /// the win condition (i.e. completed the last foundation pile).
+    ///
+    /// For replays recorded by the live engine this is always
+    /// `Some(moves.len() - 1)` because recording freezes on win — but
+    /// the field is stored explicitly so the playback UI can read it
+    /// directly without re-deriving "the last move was the win" each
+    /// time, and to leave room for future recording semantics that
+    /// might capture post-win state.
+    ///
+    /// `None` for replays loaded from disk that pre-date this field.
+    /// `#[serde(default)]` keeps older `latest_replay.json` /
+    /// `replays.json` files loadable without bumping
+    /// [`REPLAY_SCHEMA_VERSION`] — this is an additive optional
+    /// field, not a schema-breaking change.
+    ///
+    /// Surfaced by the replay-overlay scrub bar's WIN MOVE marker
+    /// (B-2 screen-takeover redesign) when present.
+    #[serde(default)]
+    pub win_move_index: Option<usize>,
 }
 
 impl Replay {
     /// Construct a fresh replay with the current schema version. The
     /// caller fills in the recorded fields; this is the canonical
     /// constructor used by the engine on win.
+    ///
+    /// [`win_move_index`](Self::win_move_index) and
+    /// [`share_url`](Self::share_url) default to `None` — the engine
+    /// uses [`with_win_move_index`](Self::with_win_move_index) at the
+    /// recording site to set the former, and `sync_plugin` writes the
+    /// latter directly when the upload task resolves.
     pub fn new(
         seed: u64,
         draw_mode: DrawMode,
@@ -172,8 +198,24 @@ impl Replay {
             recorded_at,
             moves,
             share_url: None,
+            win_move_index: None,
         }
     }
+
+    /// Builder-style setter for [`win_move_index`](Self::win_move_index).
+    /// Returns `self` so the recording site can chain it onto
+    /// [`Replay::new`]:
+    ///
+    /// ```ignore
+    /// let replay = Replay::new(...).with_win_move_index(Some(recording.moves.len() - 1));
+    /// ```
+    ///
+    /// `None` is a valid input — useful for tests that don't care about
+    /// the WIN MOVE marker's scrub-bar position.
+    pub fn with_win_move_index(mut self, idx: Option<usize>) -> Self {
+        self.win_move_index = idx;
+        self
+    }
 }
 
 /// Rolling history of the player's most recent winning replays.
@@ -737,4 +779,71 @@ mod tests {
 
         let _ = fs::remove_file(&path);
     }
+
+    // -----------------------------------------------------------------------
+    // win_move_index — additive optional field for the WIN MOVE marker
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn replay_new_defaults_win_move_index_to_none() {
+        let r = sample_replay();
+        assert_eq!(r.win_move_index, None);
+    }
+
+    #[test]
+    fn with_win_move_index_sets_value() {
+        let r = sample_replay().with_win_move_index(Some(3));
+        assert_eq!(r.win_move_index, Some(3));
+    }
+
+    #[test]
+    fn with_win_move_index_accepts_none() {
+        // Passing None through the builder is a valid no-op — useful for
+        // tests / synthetic replays that don't care about the marker.
+        let r = sample_replay().with_win_move_index(None);
+        assert_eq!(r.win_move_index, None);
+    }
+
+    #[test]
+    fn replay_with_win_move_index_round_trips_on_disk() {
+        let path = tmp_path("win_move_index_round_trip");
+        let _ = fs::remove_file(&path);
+
+        let original = sample_replay().with_win_move_index(Some(3));
+        save_latest_replay_to(&path, &original).expect("save");
+        let loaded = load_latest_replay_from(&path).expect("load");
+        assert_eq!(loaded.win_move_index, Some(3));
+        assert_eq!(loaded, original);
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Older replay files written before this field was added must still
+    /// load — `#[serde(default)]` keeps `win_move_index` optional and
+    /// defaults missing fields to `None`. This is the contract that lets
+    /// us add the field without bumping `REPLAY_SCHEMA_VERSION`.
+    #[test]
+    fn replay_without_win_move_index_loads_with_none() {
+        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.
+        let v2_no_field = r#"{
+            "schema_version": 2,
+            "seed": 1,
+            "draw_mode": "DrawOne",
+            "mode": "Classic",
+            "time_seconds": 60,
+            "final_score": 100,
+            "recorded_at": "2026-05-02",
+            "moves": []
+        }"#;
+        fs::write(&path, v2_no_field).expect("write fixture");
+
+        let loaded = load_latest_replay_from(&path).expect("load");
+        assert_eq!(loaded.win_move_index, None);
+        assert_eq!(loaded.schema_version, REPLAY_SCHEMA_VERSION);
+
+        let _ = fs::remove_file(&path);
+    }
 }

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::DrawMode;
+use solitaire_core::game_state::{DifficultyLevel, DrawMode};
 
 const APP_DIR_NAME: &str = "solitaire_quest";
 const SETTINGS_FILE_NAME: &str = "settings.json";
@@ -224,6 +224,13 @@ pub struct Settings {
     /// `#[serde(default = "default_replay_move_interval_secs")]`.
     #[serde(default = "default_replay_move_interval_secs")]
     pub replay_move_interval_secs: f32,
+    /// Last difficulty tier the player selected. `None` means the player has
+    /// never used the difficulty picker. When `Some`, the difficulty section in
+    /// the home overlay opens pre-expanded and highlights this tier. Older
+    /// `settings.json` files written before this field existed deserialize
+    /// cleanly to `None` via `#[serde(default)]`.
+    #[serde(default)]
+    pub last_difficulty: Option<DifficultyLevel>,
 }
 
 fn default_draw_mode() -> DrawMode {
@@ -342,6 +349,7 @@ impl Default for Settings {
             winnable_deals_only: false,
             disable_smart_default_size: false,
             replay_move_interval_secs: default_replay_move_interval_secs(),
+            last_difficulty: None,
         }
     }
 }

solitaire_data/src/stats.rs

@@ -104,6 +104,13 @@ impl StatsExt for StatsSnapshot {
             // Time Attack uses its own session-level scoring; a per-game best
             // wouldn't compose with the other modes' single-game numbers.
             GameMode::TimeAttack => {}
+            // Difficulty games pool into the Classic best-score/time buckets per
+            // the user's stats preference.
+            GameMode::Difficulty(_) => {
+                self.classic_best_score = self.classic_best_score.max(score_u32);
+                self.classic_fastest_win_seconds =
+                    min_ignore_zero(self.classic_fastest_win_seconds, time_seconds);
+            }
         }
         self.last_modified = Utc::now();
     }

solitaire_data/src/sync_client.rs

@@ -83,18 +83,96 @@ impl SolitaireServerClient {
         }
     }
 
+    /// Authenticate with a username + password and return `(access_token, refresh_token)`.
+    ///
+    /// On success call [`crate::auth_tokens::store_tokens`] with the returned pair.
+    /// The client's `username` field is used as the credential — the caller must
+    /// construct the client with the correct username before calling this.
+    pub async fn login(&self, password: &str) -> Result<(String, String), SyncError> {
+        let resp = self
+            .client
+            .post(format!("{}/api/auth/login", self.base_url))
+            .json(&serde_json::json!({
+                "username": self.username,
+                "password": password,
+            }))
+            .send()
+            .await
+            .map_err(|e| SyncError::Network(e.to_string()))?;
+
+        Self::extract_auth_tokens(resp).await
+    }
+
+    /// Register a new account with a username + password and return `(access_token, refresh_token)`.
+    ///
+    /// On success call [`crate::auth_tokens::store_tokens`] with the returned pair.
+    pub async fn register(&self, password: &str) -> Result<(String, String), SyncError> {
+        let resp = self
+            .client
+            .post(format!("{}/api/auth/register", self.base_url))
+            .json(&serde_json::json!({
+                "username": self.username,
+                "password": password,
+            }))
+            .send()
+            .await
+            .map_err(|e| SyncError::Network(e.to_string()))?;
+
+        Self::extract_auth_tokens(resp).await
+    }
+
+    /// Parse `{ "access_token": "...", "refresh_token": "..." }` from an auth response.
+    async fn extract_auth_tokens(resp: reqwest::Response) -> Result<(String, String), SyncError> {
+        let status = resp.status();
+        if !status.is_success() {
+            let body: serde_json::Value = resp
+                .json()
+                .await
+                .unwrap_or(serde_json::json!({}));
+            let msg = body["error"]
+                .as_str()
+                .or_else(|| body["message"].as_str())
+                .unwrap_or("authentication failed");
+            return Err(if status == reqwest::StatusCode::CONFLICT {
+                SyncError::Auth("username already taken".into())
+            } else if status == reqwest::StatusCode::UNAUTHORIZED
+                || status == reqwest::StatusCode::FORBIDDEN
+            {
+                SyncError::Auth("invalid credentials".into())
+            } else if status == reqwest::StatusCode::BAD_REQUEST {
+                SyncError::Auth(msg.to_string())
+            } else {
+                SyncError::Network(format!("server returned {status}"))
+            });
+        }
+        let body: serde_json::Value = resp
+            .json()
+            .await
+            .map_err(|e| SyncError::Serialization(e.to_string()))?;
+        let access = body["access_token"]
+            .as_str()
+            .ok_or_else(|| SyncError::Serialization("missing access_token".into()))?
+            .to_string();
+        let refresh = body["refresh_token"]
+            .as_str()
+            .ok_or_else(|| SyncError::Serialization("missing refresh_token".into()))?
+            .to_string();
+        Ok((access, refresh))
+    }
+
     /// Attempt to refresh the access token using the stored refresh token.
     ///
-    /// On success the new access token is persisted to the OS keychain,
+    /// The server rotates refresh tokens on each call: the response includes a
-    /// replacing the previous one. The refresh token itself is unchanged.
+    /// new refresh token that replaces the old one. Both tokens are persisted
+    /// to the OS keychain on success.
     async fn refresh_token(&self) -> Result<(), SyncError> {
-        let refresh = load_refresh_token(&self.username)
+        let old_refresh = load_refresh_token(&self.username)
             .map_err(|e| SyncError::Auth(e.to_string()))?;
 
         let resp = self
             .client
             .post(format!("{}/api/auth/refresh", self.base_url))
-            .json(&serde_json::json!({ "refresh_token": refresh }))
+            .json(&serde_json::json!({ "refresh_token": old_refresh }))
             .send()
             .await
             .map_err(|e| SyncError::Network(e.to_string()))?;
@@ -112,9 +190,11 @@ impl SolitaireServerClient {
             .as_str()
             .ok_or_else(|| SyncError::Serialization("missing access_token in refresh response".into()))?;
 
-        // store_tokens replaces both access and refresh; we keep the old
+        // Server rotates refresh tokens — store the new one.
-        // refresh token unchanged so its 30-day TTL is preserved.
+        // Fall back to the old token if the field is absent (pre-rotation server).
-        store_tokens(&self.username, new_access, &refresh)
+        let new_refresh = body["refresh_token"].as_str().unwrap_or(&old_refresh);
+
+        store_tokens(&self.username, new_access, new_refresh)
             .map_err(|e| SyncError::Auth(e.to_string()))
     }
 

solitaire_data/tests/sync_round_trip.rs

@@ -418,3 +418,56 @@ async fn pull_after_account_deletion_returns_default_or_error() {
 
     let _ = delete_tokens(username);
 }
+
+/// **Push retry on 401.**
+///
+/// Mirrors `jwt_refresh_on_401_succeeds` but for the `push()` path.
+/// We install an expired access token so the first push attempt returns 401,
+/// the client refreshes, and the retry push succeeds.
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn push_retries_after_401_on_expired_access_token() {
+    ensure_mock_keyring();
+
+    let base = spawn_test_server().await;
+    let username = "rt_push_expiring";
+
+    let (_real_access, real_refresh) =
+        register_user_raw(&base, username, "pushexpirepass1!").await;
+    let user_id = decode_sub(&_real_access);
+
+    #[derive(serde::Serialize)]
+    struct Claims {
+        sub: String,
+        exp: usize,
+        kind: String,
+    }
+    let exp = (Utc::now() - chrono::Duration::hours(2)).timestamp() as usize;
+    let expired_access = encode(
+        &Header::default(),
+        &Claims {
+            sub: user_id.clone(),
+            exp,
+            kind: "access".into(),
+        },
+        &EncodingKey::from_secret(TEST_SECRET.as_bytes()),
+    )
+    .expect("failed to encode expired access token");
+
+    store_tokens(username, &expired_access, &real_refresh)
+        .expect("storing tokens in mock keyring must succeed");
+
+    let client = SolitaireServerClient::new(&base, username);
+    let payload = make_payload(&user_id, 17);
+
+    // Push: server returns 401, client refreshes, retries, succeeds.
+    let push_resp = client
+        .push(&payload)
+        .await
+        .expect("push must succeed after the client transparently refreshes the access token");
+    assert_eq!(
+        push_resp.merged.stats.games_played, 17,
+        "merged games_played must reflect what was pushed after auto-refresh"
+    );
+
+    let _ = delete_tokens(username);
+}

solitaire_engine/Cargo.toml

@@ -32,6 +32,9 @@ zip            = { workspace = true }
 [target.'cfg(not(target_os = "android"))'.dependencies]
 arboard        = { workspace = true }
 
+[target.'cfg(target_os = "android")'.dependencies]
+jni            = { workspace = true }
+
 [dev-dependencies]
 async-trait = { workspace = true }
 tempfile    = { workspace = true }

solitaire_engine/src/achievement_plugin.rs

@@ -1445,6 +1445,7 @@ mod tests {
                 replay: dummy_replay(),
                 cursor: 0,
                 secs_to_next: 0.0,
+                paused: false,
             };
         app.update();
         assert!(
@@ -1480,6 +1481,7 @@ mod tests {
                 replay: dummy_replay(),
                 cursor: 0,
                 secs_to_next: 0.0,
+                paused: false,
             };
         app.update();
 
@@ -1512,6 +1514,7 @@ mod tests {
                 replay: dummy_replay(),
                 cursor: 0,
                 secs_to_next: 0.0,
+                paused: false,
             };
         app.update();
         *app.world_mut().resource_mut::<ReplayPlaybackState>() =
@@ -1534,6 +1537,7 @@ mod tests {
                 replay: dummy_replay(),
                 cursor: 0,
                 secs_to_next: 0.0,
+                paused: false,
             };
         app.update();
         *app.world_mut().resource_mut::<ReplayPlaybackState>() =
@@ -1559,6 +1563,7 @@ mod tests {
                 replay: dummy_replay(),
                 cursor: 0,
                 secs_to_next: 0.0,
+                paused: false,
             };
         app.update();
         *app.world_mut().resource_mut::<ReplayPlaybackState>() =

solitaire_engine/src/android_clipboard.rs

@@ -0,0 +1,65 @@
+/// 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"`.
+#[cfg(target_os = "android")]
+pub fn set_text(text: &str) -> Result<(), String> {
+    use bevy::android::ANDROID_APP;
+    use jni::{
+        objects::{JObject, JValueOwned},
+        JavaVM,
+    };
+
+    let app = ANDROID_APP
+        .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,
+                "getSystemService",
+                "(Ljava/lang/String;)Ljava/lang/Object;",
+                &[svc_name.borrow()],
+            )?
+            .l()?;
+
+        // ClipData clip = ClipData.newPlainText("link", text)
+        let label = JValueOwned::from(env.new_string("link")?);
+        let java_text = JValueOwned::from(env.new_string(text)?);
+        let clip_class = env.find_class("android/content/ClipData")?;
+        let clip = env
+            .call_static_method(
+                &clip_class,
+                "newPlainText",
+                "(Ljava/lang/CharSequence;Ljava/lang/CharSequence;)Landroid/content/ClipData;",
+                &[label.borrow(), java_text.borrow()],
+            )?
+            .l()?;
+
+        // cm.setPrimaryClip(clip)
+        let clip_val = JValueOwned::Object(clip);
+        env.call_method(
+            &cm,
+            "setPrimaryClip",
+            "(Landroid/content/ClipData;)V",
+            &[clip_val.borrow()],
+        )?
+        .v()
+    })()
+    .map_err(|e| format!("clipboard JNI: {e}"))
+}

solitaire_engine/src/animation_plugin.rs

@@ -21,8 +21,10 @@ use crate::card_animation::{sample_curve, CardAnimation, MotionCurve};
 use crate::card_plugin::CardEntity;
 use crate::challenge_plugin::ChallengeAdvancedEvent;
 use crate::daily_challenge_plugin::{DailyChallengeCompletedEvent, DailyGoalAnnouncementEvent};
-use crate::events::{InfoToastEvent, XpAwardedEvent};
+use crate::events::{
-use crate::events::{AchievementUnlockedEvent, GameWonEvent};
+    AchievementUnlockedEvent, GameWonEvent, InfoToastEvent, MoveRejectedEvent, WarningToastEvent,
+    XpAwardedEvent,
+};
 use crate::game_plugin::GameMutation;
 use crate::layout::LayoutResource;
 use crate::pause_plugin::PausedResource;
@@ -162,6 +164,8 @@ impl Plugin for AnimationPlugin {
             .add_message::<ChallengeAdvancedEvent>()
             .add_message::<SettingsChangedEvent>()
             .add_message::<InfoToastEvent>()
+            .add_message::<MoveRejectedEvent>()
+            .add_message::<WarningToastEvent>()
             .add_message::<XpAwardedEvent>()
             .init_resource::<EffectiveSlideDuration>()
             .init_resource::<ToastQueue>()
@@ -183,6 +187,8 @@ impl Plugin for AnimationPlugin {
                     handle_settings_toast,
                     handle_auto_complete_toast,
                     handle_xp_awarded_toast,
+                    handle_move_rejected_toast,
+                    handle_warning_toast,
                     tick_toasts,
                     (enqueue_toasts, drive_toast_display).chain(),
                 )
@@ -565,9 +571,11 @@ pub enum ToastVariant {
     /// event; kept so future warning-flavoured toasts have a slot.
     #[allow(dead_code)]
     Warning,
-    /// Failure / rejected action — pink border. Currently unused; kept so
+    /// Failure / rejected action — pink border. Used by
-    /// future error-flavoured toasts have a slot.
+    /// [`handle_move_rejected_toast`] for illegal-placement
-    #[allow(dead_code)]
+    /// feedback; the third leg of the rejection-feedback stool
+    /// alongside `card_invalid.wav` (audio) and the destination-
+    /// pile shake (visual).
     Error,
     /// Reward / milestone — lavender border. Used for XP awards,
     /// achievement unlocks, level-ups, daily/weekly/challenge completions.
@@ -622,6 +630,47 @@ fn handle_xp_awarded_toast(mut commands: Commands, mut events: MessageReader<XpA
     }
 }
 
+/// Spawns a 2-second pink-bordered Error toast when the player tries an
+/// illegal placement (`MoveRejectedEvent`). Adds a third leg to the
+/// existing rejection feedback stool — `card_invalid.wav` already plays
+/// (audio cue) and `feedback_anim_plugin::queue_shake_for_rejected_move`
+/// fires the destination-pile shake (visual cue). The toast is the
+/// accessibility-focused leg: persistent ~2 s text that's readable for
+/// deaf players and impossible to miss for players who blink during the
+/// shake. First in-engine consumer of `ToastVariant::Error` — exercises
+/// the variant's pink border accent and the design-system "rejected
+/// action" semantic.
+fn handle_move_rejected_toast(
+    mut commands: Commands,
+    mut events: MessageReader<MoveRejectedEvent>,
+) {
+    for _ev in events.read() {
+        spawn_toast(
+            &mut commands,
+            "Invalid move".to_string(),
+            2.0,
+            ToastVariant::Error,
+        );
+    }
+}
+
+/// Spawns a 4-second amber-bordered Warning toast for every incoming
+/// [`WarningToastEvent`]. First in-engine consumer of
+/// [`ToastVariant::Warning`] — exercises the variant's amber accent and
+/// the design-system "act soon" semantic.
+///
+/// Mirrors [`handle_move_rejected_toast`] but reads a generic carrier
+/// event (not a domain-specific one) because Warning has multiple
+/// candidate drivers and the call-site knows the message wording.
+fn handle_warning_toast(
+    mut commands: Commands,
+    mut events: MessageReader<WarningToastEvent>,
+) {
+    for ev in events.read() {
+        spawn_toast(&mut commands, ev.0.clone(), 4.0, ToastVariant::Warning);
+    }
+}
+
 /// Ticks down `ToastTimer` on each toast and despawns it when the timer expires.
 ///
 /// Skipped while the game is paused so toast countdowns freeze along with the
@@ -966,6 +1015,44 @@ mod tests {
         let _ = count;
     }
 
+    #[test]
+    fn move_rejected_event_spawns_error_toast() {
+        // The first in-engine consumer of `ToastVariant::Error`. Firing
+        // a `MoveRejectedEvent` (illegal placement) must spawn exactly
+        // one `ToastOverlay` carrying the rejection-feedback message.
+        // 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;
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins).add_plugins(AnimationPlugin);
+
+        // Baseline: no toast overlays exist before the event.
+        let before = app
+            .world_mut()
+            .query::<&ToastOverlay>()
+            .iter(app.world())
+            .count();
+
+        app.world_mut().write_message(MoveRejectedEvent {
+            from: PileType::Tableau(0),
+            to: PileType::Tableau(1),
+            count: 1,
+        });
+        app.update();
+
+        let after = app
+            .world_mut()
+            .query::<&ToastOverlay>()
+            .iter(app.world())
+            .count();
+        assert_eq!(
+            after,
+            before + 1,
+            "MoveRejectedEvent must spawn exactly one error toast",
+        );
+    }
+
     // -----------------------------------------------------------------------
     // Task #67 — Toast queue pure-function tests
     // -----------------------------------------------------------------------

solitaire_engine/src/card_animation/tuning.rs

@@ -114,7 +114,7 @@ impl AnimationTuning {
             platform: InputPlatform::Touch,
             duration_scale: 0.75,
             overshoot_scale: 0.5,
-            drag_threshold_px: 10.0,
+            drag_threshold_px: 8.0,  // Android ViewConfiguration.getScaledTouchSlop()
             drag_scale: 1.12,
             hover_scale: 1.0, // no hover affordance on touch
             hover_lerp_speed: 20.0,

solitaire_engine/src/card_plugin.rs

@@ -35,13 +35,12 @@ 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, STOCK_BADGE_BG, STOCK_BADGE_FG, TEXT_PRIMARY, TEXT_PRIMARY_HC,
-    TYPE_CAPTION, Z_STOCK_BADGE,
+    TYPE_BODY, Z_STOCK_BADGE,
 };
 
 /// Fraction of card height used as vertical offset between face-up tableau cards.
 pub const TABLEAU_FAN_FRAC: f32 = 0.25;
 
-/// Tighter fan for face-down cards in the tableau — just enough to show the stack.
 /// Per-card vertical step for face-down tableau cards, as a fraction of
 /// card height. Smaller than [`TABLEAU_FAN_FRAC`] because face-down cards
 /// don't need their full body shown — only the back-pattern strip is
@@ -49,7 +48,12 @@ pub const TABLEAU_FAN_FRAC: f32 = 0.25;
 /// when hit-testing tableau columns; any drift between this and the
 /// renderer creates a visible offset between the card face and where
 /// clicks land.
-pub const TABLEAU_FACEDOWN_FAN_FRAC: f32 = 0.12;
+///
+/// Matches `layout::TABLEAU_FACEDOWN_FAN_FRAC` (0.20). 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 = 0.20;
 
 /// Fraction of card height used as a tiny offset between stacked cards in
 /// non-tableau piles, so stacking is visible. Public so other plugins
@@ -263,6 +267,23 @@ pub struct ShadowEntity;
 #[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. Medium gray so it reads as
+/// a neutral "edge" without competing with the suit colours on face-up cards.
+const CARD_BACK_FRAME_COLOR: Color = Color::srgb(0.38, 0.38, 0.38);
+
+/// Extra width/height (in world units) added to each side of the card to form
+/// the visible border. 3 world units ≈ 3 dp on a 1× screen.
+const CARD_BACK_FRAME_PADDING: f32 = 3.0;
+
 /// 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
@@ -318,6 +339,21 @@ fn add_card_shadow_child(parent: &mut ChildSpawnerCommands, card_size: Vec2) {
     ));
 }
 
+/// Spawns a `CardBackFrame` child behind a face-down card entity so the dark
+/// back PNG has a visible perimeter against the dark felt.
+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
@@ -373,6 +409,9 @@ impl Plugin for CardPlugin {
             .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),
@@ -649,16 +688,25 @@ fn card_positions<'a>(game: &'a GameState, layout: &Layout) -> Vec<(&'a Card, Ve
                 DrawMode::DrawOne => 1_usize,
                 DrawMode::DrawThree => 3_usize,
             };
-            cards.len().saturating_sub(visible)
+            // 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) in cards[render_start..].iter().enumerate() {
             let x_offset = if is_waste && matches!(game.draw_mode, DrawMode::DrawThree) {
-                // Fan left→right; top card (last slot) is rightmost and playable.
+                // When len > visible, slot 0 is a hidden buffer card kept at
-                slot as f32 * layout.card_size.x * 0.28
+                // 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 * layout.card_size.x * 0.28
             } else {
                 0.0
             };
@@ -667,9 +715,9 @@ fn card_positions<'a>(game: &'a GameState, layout: &Layout) -> Vec<(&'a Card, Ve
             out.push((card, pos, z));
             if is_tableau {
                 let step = if card.face_up {
-                    TABLEAU_FAN_FRAC
+                    layout.tableau_fan_frac
                 } else {
-                    TABLEAU_FACEDOWN_FAN_FRAC
+                    layout.tableau_facedown_fan_frac
                 };
                 y_offset -= layout.card_size.y * step;
             }
@@ -706,6 +754,13 @@ fn spawn_card_entity(
     entity.with_children(|b| {
         add_card_shadow_child(b, layout.card_size);
     });
+    // Face-down cards get a thin contrasting border frame so the dark back
+    // PNG reads as a distinct rectangle against the dark felt.
+    if !card.face_up {
+        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).
     if card_images.is_none() {
@@ -781,6 +836,11 @@ fn update_card_entity(
     commands.entity(entity).with_children(|b| {
         add_card_shadow_child(b, layout.card_size);
     });
+    if !card.face_up {
+        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((
@@ -1438,8 +1498,8 @@ fn update_stock_empty_indicator(
 const STOCK_BADGE_INSET: Vec2 = Vec2::new(-12.0, -8.0);
 
 /// Width / height of the badge background sprite, in world pixels. Sized so
-/// a 2-digit count (max "24") fits comfortably with `TYPE_CAPTION` text.
+/// a 2-digit count (max "24") fits comfortably with `TYPE_BODY` (14 pt) text.
-const STOCK_BADGE_SIZE: Vec2 = Vec2::new(28.0, 16.0);
+const STOCK_BADGE_SIZE: Vec2 = Vec2::new(34.0, 20.0);
 
 /// Returns the count of cards currently in the stock pile.
 ///
@@ -1484,7 +1544,7 @@ fn spawn_stock_count_badge(
     };
     let text_font = TextFont {
         font: font.cloned().unwrap_or_default(),
-        font_size: TYPE_CAPTION,
+        font_size: TYPE_BODY,
         ..default()
     };
 
@@ -1629,13 +1689,20 @@ fn snap_cards_on_window_resize(
     card_images: Option<Res<CardImageSet>>,
     entities: Query<
         (Entity, &CardEntity, &mut Sprite, &mut Transform),
-        (Without<CardLabel>, Without<CardShadow>),
+        (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>)>,
+    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<CardEntity>, Without<CardShadow>, Without<CardBackFrame>),
     >,
     label_children: Query<(Entity, &ChildOf), With<StockEmptyLabel>>,
 ) {
@@ -1665,6 +1732,7 @@ fn snap_cards_on_window_resize(
         entities,
         label_query,
         shadow_query,
+        frame_query,
     );
 
     apply_stock_empty_indicator(
@@ -1691,7 +1759,7 @@ fn snap_cards_on_window_resize(
 ///
 /// 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)]
+#[allow(clippy::type_complexity, clippy::too_many_arguments)]
 fn resize_cards_in_place(
     commands: &mut Commands,
     game: &GameState,
@@ -1699,12 +1767,16 @@ fn resize_cards_in_place(
     card_images: Option<&CardImageSet>,
     mut entities: Query<
         (Entity, &CardEntity, &mut Sprite, &mut Transform),
-        (Without<CardLabel>, Without<CardShadow>),
+        (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>),
+        (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);
@@ -1756,6 +1828,62 @@ fn resize_cards_in_place(
             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);
+    }
+}
+
+/// Adjusts `LayoutResource.tableau_fan_frac` to match the current maximum
+/// face-up column depth. Runs after every `StateChangedEvent` so the fan
+/// expands as the player reveals cards while staying within the window.
+///
+/// On fresh deal (max face-up depth = 1) the function returns early, leaving
+/// both fracs at the window-size-adaptive values that `compute_layout` already
+/// computed for the current viewport. Previously it overwrote the adaptive
+/// value with the desktop minimum (0.25) — the wrong behaviour on portrait
+/// phones where the adaptive value is much larger.
+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; };
+
+    let max_depth = (0..7_usize)
+        .filter_map(|i| game.0.piles.get(&solitaire_core::pile::PileType::Tableau(i)))
+        .map(|pile| pile.cards.iter().filter(|c| c.face_up).count())
+        .max()
+        .unwrap_or(0);
+
+    let card_h = layout.0.card_size.y;
+    let avail = layout.0.available_tableau_height;
+
+    // With ≤ 1 face-up card per column (fresh deal, or completely face-down
+    // piles) the face-up fan fraction has no visible effect. Leave both fracs
+    // at the adaptive values set by compute_layout rather than snapping them
+    // to the desktop minimum.
+    if max_depth <= 1 || card_h <= 0.0 {
+        return;
+    }
+
+    let ideal = avail / ((max_depth - 1) as f32 * card_h);
+    let max_frac = if card_h > 0.0 { avail / (12.0 * card_h) } else { TABLEAU_FAN_FRAC };
+    let new_frac = ideal.clamp(TABLEAU_FAN_FRAC, max_frac.max(TABLEAU_FAN_FRAC));
+    let new_facedown_frac = new_frac * (TABLEAU_FACEDOWN_FAN_FRAC / TABLEAU_FAN_FRAC);
+
+    if (layout.0.tableau_fan_frac - new_frac).abs() > 1e-4 {
+        layout.0.tableau_fan_frac = new_frac;
+    }
+    if (layout.0.tableau_facedown_fan_frac - new_facedown_frac).abs() > 1e-4 {
+        layout.0.tableau_facedown_fan_frac = new_facedown_frac;
+    }
 }
 
 #[cfg(test)]
@@ -1862,7 +1990,7 @@ mod tests {
         // At game start waste is empty, so all 52 cards are across stock + tableau.
         let g = GameState::new(42, solitaire_core::game_state::DrawMode::DrawOne);
         let layout =
-            crate::layout::compute_layout(Vec2::new(1280.0, 800.0));
+            crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let positions = card_positions(&g, &layout);
         assert_eq!(positions.len(), 52);
     }
@@ -1882,7 +2010,7 @@ mod tests {
             .collect();
         assert_eq!(waste_ids.len(), 3);
 
-        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let positions = card_positions(&g, &layout);
 
         // Filter rendered positions to only waste cards (by card ID).
@@ -1890,11 +2018,13 @@ mod tests {
             .iter()
             .filter(|(card, _, _)| waste_ids.contains(&card.id))
             .collect();
-        // Draw-One: only 1 waste card should be rendered regardless of pile depth.
+        // Draw-One: renders up to 2 waste cards (1 visible + 1 hidden to
-        assert_eq!(waste_rendered.len(), 1);
+        // prevent the evicted card from flashing during the draw tween).
-        // The single rendered card must be the top (last) waste card.
+        assert!(waste_rendered.len() <= 2, "Draw-One renders at most 2 waste cards");
+        assert!(!waste_rendered.is_empty(), "at least the top waste card must be rendered");
+        // The top (last) waste card must always be among the rendered cards.
         let top_id = g.piles[&PileType::Waste].cards.last().unwrap().id;
-        assert_eq!(waste_rendered[0].0.id, top_id);
+        assert!(waste_rendered.iter().any(|(c, _, _)| c.id == top_id), "top waste card must be rendered");
     }
 
     #[test]
@@ -1911,32 +2041,73 @@ mod tests {
         let waste_ids: std::collections::HashSet<u32> =
             waste_pile.iter().map(|c| c.id).collect();
 
-        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let positions = card_positions(&g, &layout);
 
         let mut waste_rendered: Vec<_> = positions
             .iter()
             .filter(|(card, _, _)| waste_ids.contains(&card.id))
             .collect();
-        // Draw-Three: at most 3 waste cards rendered.
+        // Draw-Three: at most 4 waste cards rendered (3 visible + 1 hidden to
-        assert_eq!(waste_rendered.len(), 3);
+        // prevent the evicted card from flashing during the draw tween).
+        assert!(waste_rendered.len() <= 4, "Draw-Three renders at most 4 waste cards");
+        assert!(waste_rendered.len() >= 3, "Draw-Three renders at least 3 waste cards when pile is deep enough");
 
-        // The three fanned cards must have strictly increasing X coordinates
+        // The three visible fanned cards (slots 1–3) must have strictly
-        // (left = oldest visible, right = top/playable).
+        // increasing X coordinates. The hidden extra card at slot 0 sits at x=0.
         waste_rendered.sort_by(|a, b| a.1.x.partial_cmp(&b.1.x).unwrap());
-        for w in waste_rendered.windows(2) {
+        // The top 3 cards (after the hidden one) must be fanned.
-            assert!(w[1].1.x > w[0].1.x, "fanned waste cards must have distinct X positions");
+        let visible = &waste_rendered[waste_rendered.len().saturating_sub(3)..];
+        for w in visible.windows(2) {
+            assert!(w[1].1.x >= w[0].1.x, "fanned waste cards must have non-decreasing X positions");
         }
-        // Top card (rightmost) must be the last card in the waste pile.
+        // Top card (rightmost by x) must be the last card in the waste pile.
         let top_id = waste_pile.last().unwrap().id;
         assert_eq!(waste_rendered.last().unwrap().0.id, top_id);
     }
 
+    #[test]
+    fn waste_draw_three_fans_correctly_when_pile_smaller_than_visible() {
+        // Regression: slot.saturating_sub(1) always hid slot-0 even when the
+        // pile was too small to have a buffer card, collapsing 2 visible cards
+        // onto x=0 instead of fanning them.
+        use solitaire_core::game_state::DrawMode;
+        let mut g = GameState::new(42, DrawMode::DrawThree);
+        // Draw exactly once — in Draw-Three mode with a full stock this gives
+        // 3 waste cards (still ≤ visible=3, so no hidden buffer needed).
+        let _ = g.draw();
+        let waste_pile = &g.piles[&PileType::Waste].cards;
+        // We need exactly 2 or 3 waste cards to hit the small-pile path.
+        // One draw in Draw-Three adds up to 3 cards; take the first 2 if needed.
+        let count = waste_pile.len();
+        assert!(count >= 2, "need at least 2 waste cards");
+
+        let waste_ids: std::collections::HashSet<u32> =
+            waste_pile.iter().map(|c| c.id).collect();
+        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
+        let positions = card_positions(&g, &layout);
+
+        let mut waste_rendered: Vec<_> = positions
+            .iter()
+            .filter(|(card, _, _)| waste_ids.contains(&card.id))
+            .collect();
+        // All waste cards should be visible (no hidden buffer when len ≤ visible).
+        assert_eq!(waste_rendered.len(), count, "all waste cards rendered when pile ≤ visible");
+
+        // Cards must be fanned with distinct x positions (or equal for 1-card).
+        waste_rendered.sort_by(|a, b| a.1.x.partial_cmp(&b.1.x).unwrap());
+        if count >= 2 {
+            let last = waste_rendered.last().unwrap();
+            let second_last = &waste_rendered[waste_rendered.len() - 2];
+            assert!(last.1.x > second_last.1.x, "top 2 waste cards must fan to distinct x positions");
+        }
+    }
+
     #[test]
     fn card_positions_tableau_cards_are_fanned_downward() {
         let g = GameState::new(42, solitaire_core::game_state::DrawMode::DrawOne);
         let layout =
-            crate::layout::compute_layout(Vec2::new(1280.0, 800.0));
+            crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let positions = card_positions(&g, &layout);
 
         // Collect positions for Tableau(6) (should have 7 cards).
@@ -2248,7 +2419,7 @@ mod tests {
     #[test]
     fn facedown_cards_use_tighter_fan_than_uniform_faceup_fan() {
         let g = GameState::new(42, solitaire_core::game_state::DrawMode::DrawOne);
-        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let positions = card_positions(&g, &layout);
 
         // Tableau(6) has 7 cards: 6 face-down + 1 face-up on top.
@@ -2409,7 +2580,7 @@ mod tests {
         // Sanity-check: the new font size matches FONT_SIZE_FRAC × the
         // post-resize card width, so the in-place path is using the
         // refreshed Layout.
-        let expected_layout = crate::layout::compute_layout(Vec2::new(800.0, 600.0));
+        let expected_layout = crate::layout::compute_layout(Vec2::new(800.0, 600.0), 0.0, 0.0);
         let expected = expected_layout.card_size.x * FONT_SIZE_FRAC;
         assert!(
             (after - expected).abs() < 1e-3,

solitaire_engine/src/cursor_plugin.rs

@@ -604,7 +604,7 @@ mod tests {
         use crate::layout::compute_layout;
 
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         // A cursor far off-screen should never hit anything.
         assert!(!cursor_over_draggable(Vec2::new(-9999.0, -9999.0), &game, &layout));
     }
@@ -624,7 +624,7 @@ mod tests {
         let mut app = App::new();
         app.add_plugins(MinimalPlugins)
             .insert_resource(GameStateResource(game))
-            .insert_resource(LayoutResource(compute_layout(Vec2::new(1280.0, 800.0))))
+            .insert_resource(LayoutResource(compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0)))
             .insert_resource(DragState::default())
             .add_systems(Update, update_drop_target_overlays);
         app

solitaire_engine/src/daily_challenge_plugin.rs

@@ -14,13 +14,13 @@
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
 use bevy::tasks::{futures_lite::future, AsyncComputeTaskPool, Task};
-use chrono::{Local, NaiveDate};
+use chrono::{DateTime, Duration, Local, NaiveDate, Utc};
 use solitaire_data::{daily_seed_for, save_progress_to};
 use solitaire_sync::ChallengeGoal;
 
 use crate::events::{
     GameWonEvent, InfoToastEvent, NewGameRequestEvent, StartDailyChallengeRequestEvent,
-    XpAwardedEvent,
+    WarningToastEvent, XpAwardedEvent,
 };
 use crate::game_plugin::GameMutation;
 use crate::progress_plugin::{ProgressResource, ProgressStoragePath, ProgressUpdate};
@@ -30,6 +30,11 @@ use crate::sync_plugin::SyncProviderResource;
 /// Bonus XP awarded for completing today's daily challenge.
 pub const DAILY_BONUS_XP: u64 = 100;
 
+/// Minutes before UTC midnight at which the daily-challenge expiry warning
+/// fires. The reset is global (UTC), so the warning is global too — local
+/// midnight may be hours away or already past.
+pub const DAILY_EXPIRY_WARNING_MINUTES: i64 = 30;
+
 /// The active daily challenge — date + RNG seed for that date's deal,
 /// plus optional goal metadata fetched from the server.
 #[derive(Resource, Debug, Clone)]
@@ -74,6 +79,16 @@ pub struct DailyChallengeCompletedEvent {
 #[derive(Resource, Default)]
 struct DailyChallengeTask(Option<Task<Option<ChallengeGoal>>>);
 
+/// Tracks which `DailyChallengeResource::date` the expiry-warning toast has
+/// already fired for, so the toast spawns at most once per day.
+///
+/// `None` until the first warning fires; thereafter holds the date the
+/// warning was shown for. When `daily.date` advances (a new local day rolls
+/// over while the app stays open), this becomes stale and the next warning
+/// can fire.
+#[derive(Resource, Default, Debug)]
+struct DailyExpiryWarningShown(Option<NaiveDate>);
+
 /// Fetches today's daily challenge seed and goal from the sync server on startup and tracks completion.
 /// Fires `DailyChallengeCompletedEvent` when the player wins a matching game.
 pub struct DailyChallengePlugin;
@@ -82,18 +97,21 @@ impl Plugin for DailyChallengePlugin {
     fn build(&self, app: &mut App) {
         app.insert_resource(DailyChallengeResource::for_today())
             .init_resource::<DailyChallengeTask>()
+            .init_resource::<DailyExpiryWarningShown>()
             .add_message::<DailyChallengeCompletedEvent>()
             .add_message::<DailyGoalAnnouncementEvent>()
             .add_message::<GameWonEvent>()
             .add_message::<NewGameRequestEvent>()
             .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, handle_start_daily_request.before(GameMutation))
+            .add_systems(Update, check_daily_expiry_warning);
     }
 }
 
@@ -215,6 +233,71 @@ fn handle_start_daily_request(
     announce.write(DailyGoalAnnouncementEvent(desc));
 }
 
+/// Pure decision logic for the daily-challenge expiry warning. Returns the
+/// integer minutes-until-UTC-midnight if a warning toast should fire on this
+/// frame, or `None` if any suppression condition holds.
+///
+/// Suppression rules (in order):
+/// 1. Player has already completed today's daily challenge.
+/// 2. The warning has already fired for `daily_date`.
+/// 3. UTC midnight is more than [`DAILY_EXPIRY_WARNING_MINUTES`] away.
+/// 4. UTC midnight has already passed for the current calendar day (the
+///    minutes-remaining is negative — happens for at most one frame at the
+///    rollover boundary).
+///
+/// Factored out so the threshold/clock behavior is unit-testable without an
+/// `App`.
+fn compute_expiry_warning_minutes(
+    daily_date: NaiveDate,
+    last_completed: Option<NaiveDate>,
+    last_shown: Option<NaiveDate>,
+    now_utc: DateTime<Utc>,
+    threshold_mins: i64,
+) -> Option<i64> {
+    if last_completed == Some(daily_date) {
+        return None;
+    }
+    if last_shown == Some(daily_date) {
+        return None;
+    }
+    let next_midnight = (now_utc.date_naive() + Duration::days(1))
+        .and_hms_opt(0, 0, 0)?
+        .and_utc();
+    let mins_remaining = (next_midnight - now_utc).num_minutes();
+    if !(0..=threshold_mins).contains(&mins_remaining) {
+        return None;
+    }
+    Some(mins_remaining)
+}
+
+/// Each-frame check for the daily-challenge expiry warning. Fires a single
+/// [`WarningToastEvent`] when the player is within
+/// [`DAILY_EXPIRY_WARNING_MINUTES`] of UTC midnight reset and hasn't yet
+/// completed today's challenge.
+///
+/// Idempotent — `DailyExpiryWarningShown` ensures the toast spawns at most
+/// once per `daily.date`.
+fn check_daily_expiry_warning(
+    daily: Res<DailyChallengeResource>,
+    progress: Res<ProgressResource>,
+    mut shown: ResMut<DailyExpiryWarningShown>,
+    mut warning: MessageWriter<WarningToastEvent>,
+) {
+    let Some(mins) = compute_expiry_warning_minutes(
+        daily.date,
+        progress.0.daily_challenge_last_completed,
+        shown.0,
+        Utc::now(),
+        DAILY_EXPIRY_WARNING_MINUTES,
+    ) else {
+        return;
+    };
+    shown.0 = Some(daily.date);
+    warning.write(WarningToastEvent(format!(
+        "Daily challenge expires in {mins} min"
+    )));
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -385,4 +468,141 @@ mod tests {
         assert_eq!(r.target_score, Some(1_000));
         assert_eq!(r.max_time_secs, Some(300));
     }
+
+    // -----------------------------------------------------------------------
+    // Daily-expiry warning toast (compute_expiry_warning_minutes + system)
+    // -----------------------------------------------------------------------
+
+    fn ymd(y: i32, m: u32, d: u32) -> NaiveDate {
+        NaiveDate::from_ymd_opt(y, m, d).unwrap()
+    }
+
+    /// Construct a UTC `DateTime` at the given calendar position. Used to
+    /// drive the pure helper through every threshold edge.
+    fn utc_at(y: i32, m: u32, d: u32, h: u32, min: u32) -> DateTime<Utc> {
+        ymd(y, m, d).and_hms_opt(h, min, 0).unwrap().and_utc()
+    }
+
+    #[test]
+    fn warning_fires_inside_threshold_when_incomplete_and_unseen() {
+        // 23:50 UTC, 10 min until reset, < 30 min threshold.
+        let now = utc_at(2026, 5, 8, 23, 50);
+        let mins = compute_expiry_warning_minutes(ymd(2026, 5, 8), None, None, now, 30);
+        assert_eq!(mins, Some(10));
+    }
+
+    #[test]
+    fn warning_fires_at_exact_threshold_boundary() {
+        // 23:30 UTC, exactly 30 min remaining — the inclusive boundary.
+        let now = utc_at(2026, 5, 8, 23, 30);
+        let mins = compute_expiry_warning_minutes(ymd(2026, 5, 8), None, None, now, 30);
+        assert_eq!(mins, Some(30));
+    }
+
+    #[test]
+    fn warning_suppressed_outside_threshold() {
+        // 23:00 UTC, 60 min remaining — outside the 30 min window.
+        let now = utc_at(2026, 5, 8, 23, 0);
+        let mins = compute_expiry_warning_minutes(ymd(2026, 5, 8), None, None, now, 30);
+        assert_eq!(mins, None);
+    }
+
+    #[test]
+    fn warning_suppressed_when_already_completed_today() {
+        // 23:50 UTC inside threshold, but today is already done.
+        let now = utc_at(2026, 5, 8, 23, 50);
+        let mins = compute_expiry_warning_minutes(
+            ymd(2026, 5, 8),
+            Some(ymd(2026, 5, 8)),
+            None,
+            now,
+            30,
+        );
+        assert_eq!(mins, None);
+    }
+
+    #[test]
+    fn warning_suppressed_when_yesterdays_completion_is_stale() {
+        // Yesterday's completion is irrelevant — we want to warn about today.
+        let now = utc_at(2026, 5, 8, 23, 50);
+        let mins = compute_expiry_warning_minutes(
+            ymd(2026, 5, 8),
+            Some(ymd(2026, 5, 7)),
+            None,
+            now,
+            30,
+        );
+        assert_eq!(mins, Some(10));
+    }
+
+    #[test]
+    fn warning_suppressed_when_already_shown_for_this_date() {
+        let now = utc_at(2026, 5, 8, 23, 50);
+        let mins = compute_expiry_warning_minutes(
+            ymd(2026, 5, 8),
+            None,
+            Some(ymd(2026, 5, 8)),
+            now,
+            30,
+        );
+        assert_eq!(mins, None);
+    }
+
+    #[test]
+    fn warning_fires_when_last_shown_was_yesterday() {
+        // Player kept the app open across a midnight rollover. Stale
+        // "shown" date doesn't suppress today's warning.
+        let now = utc_at(2026, 5, 8, 23, 50);
+        let mins = compute_expiry_warning_minutes(
+            ymd(2026, 5, 8),
+            None,
+            Some(ymd(2026, 5, 7)),
+            now,
+            30,
+        );
+        assert_eq!(mins, Some(10));
+    }
+
+    #[test]
+    fn check_system_fires_warning_event_only_once_per_day() {
+        // The pure helper is exhaustively tested above. This test verifies
+        // the system that consumes it correctly stores the "shown" date so
+        // the WarningToastEvent fires at most once per `daily.date`, even
+        // when the system runs many frames in a row inside the threshold.
+        //
+        // The system reads `Utc::now()` directly, so we can't pin the clock.
+        // Instead, we simulate the post-warning state by pre-populating
+        // `DailyExpiryWarningShown` with `daily.date` and asserting nothing
+        // fires; then we verify the symmetric "completed today" suppression.
+        let mut app = headless_app();
+        let today = app.world().resource::<DailyChallengeResource>().date;
+
+        // Pre-mark warning as already shown for today.
+        app.world_mut()
+            .resource_mut::<DailyExpiryWarningShown>()
+            .0 = Some(today);
+        app.update();
+        let events = app.world().resource::<Messages<WarningToastEvent>>();
+        let mut cursor = events.get_cursor();
+        assert!(
+            cursor.read(events).next().is_none(),
+            "no warning fires when DailyExpiryWarningShown already covers today"
+        );
+
+        // Reset shown, mark today as completed.
+        app.world_mut()
+            .resource_mut::<DailyExpiryWarningShown>()
+            .0 = None;
+        app.world_mut()
+            .resource_mut::<ProgressResource>()
+            .0
+            .daily_challenge_last_completed = Some(today);
+        app.update();
+        let events = app.world().resource::<Messages<WarningToastEvent>>();
+        let mut cursor = events.get_cursor();
+        assert!(
+            cursor.read(events).next().is_none(),
+            "no warning fires when today is already completed"
+        );
+    }
 }

solitaire_engine/src/difficulty_plugin.rs

@@ -0,0 +1,235 @@
+//! Difficulty-tier game-start plugin.
+//!
+//! Handles [`StartDifficultyRequestEvent`] by picking the next seed from the
+//! appropriate pre-verified catalog in `solitaire_data::difficulty_seeds` and
+//! writing a [`NewGameRequestEvent`]. For [`DifficultyLevel::Random`] a
+//! system-time seed is used instead — the deal may or may not be winnable.
+//!
+//! # Catalog cycling
+//!
+//! Each tier maintains an independent cursor in [`DifficultyIndexResource`]
+//! that advances one step each time a game is started at that tier. The cursor
+//! wraps modulo the catalog length so players never run out of variety. The
+//! resource is *not* persisted — it resets to 0 on every launch, which is fine
+//! 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 bevy::prelude::*;
+use solitaire_core::game_state::{DifficultyLevel, GameMode};
+use solitaire_data::difficulty_seeds::seeds_for;
+
+use crate::events::{NewGameRequestEvent, StartDifficultyRequestEvent};
+use crate::game_plugin::GameMutation;
+
+// ---------------------------------------------------------------------------
+// Resources
+// ---------------------------------------------------------------------------
+
+/// Per-tier catalog cursors. Each value is the index of the **next** seed to
+/// deal from that tier's catalog. Wraps modulo the catalog length.
+#[derive(Resource, Default)]
+pub struct DifficultyIndexResource {
+    easy: usize,
+    medium: usize,
+    hard: usize,
+    expert: usize,
+    grandmaster: usize,
+}
+
+impl DifficultyIndexResource {
+    /// Advance the cursor for `level` and return the seed at the old position.
+    /// Falls back to a system-time seed if the catalog is unexpectedly empty.
+    pub fn next_seed(&mut self, level: DifficultyLevel) -> u64 {
+        let Some(catalog) = seeds_for(level) else {
+            return seed_from_system_time();
+        };
+        if catalog.is_empty() {
+            return seed_from_system_time();
+        }
+        let cursor = match level {
+            DifficultyLevel::Easy => &mut self.easy,
+            DifficultyLevel::Medium => &mut self.medium,
+            DifficultyLevel::Hard => &mut self.hard,
+            DifficultyLevel::Expert => &mut self.expert,
+            DifficultyLevel::Grandmaster => &mut self.grandmaster,
+            DifficultyLevel::Random => unreachable!("Random has no catalog"),
+        };
+        let seed = catalog[*cursor % catalog.len()];
+        *cursor = cursor.wrapping_add(1);
+        seed
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Plugin
+// ---------------------------------------------------------------------------
+
+/// Registers all difficulty-mode systems and resources.
+pub struct DifficultyPlugin;
+
+impl Plugin for DifficultyPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<DifficultyIndexResource>()
+            .add_message::<StartDifficultyRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
+            .add_systems(
+                Update,
+                handle_difficulty_request.before(GameMutation),
+            );
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Systems
+// ---------------------------------------------------------------------------
+
+/// Resolves `StartDifficultyRequestEvent` → catalog seed → `NewGameRequestEvent`.
+fn handle_difficulty_request(
+    mut requests: MessageReader<StartDifficultyRequestEvent>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
+    mut index: ResMut<DifficultyIndexResource>,
+) {
+    for ev in requests.read() {
+        let seed = if ev.level == DifficultyLevel::Random {
+            seed_from_system_time()
+        } else {
+            index.next_seed(ev.level)
+        };
+
+        new_game.write(NewGameRequestEvent {
+            seed: Some(seed),
+            mode: Some(GameMode::Difficulty(ev.level)),
+            confirmed: false,
+        });
+    }
+}
+
+fn seed_from_system_time() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map(|d| d.as_nanos() as u64)
+        .unwrap_or(0xD1FF_0000_DEAD_BEEF)
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::game_plugin::GamePlugin;
+    use crate::table_plugin::TablePlugin;
+    use solitaire_data::difficulty_seeds::{EASY_SEEDS, MEDIUM_SEEDS};
+
+    fn headless_app() -> App {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(GamePlugin)
+            .add_plugins(TablePlugin)
+            .add_plugins(DifficultyPlugin);
+        app.update();
+        app
+    }
+
+    fn fire_request(app: &mut App, level: DifficultyLevel) {
+        app.world_mut()
+            .write_message(StartDifficultyRequestEvent { level });
+        app.update();
+    }
+
+    fn drain_new_game_events(app: &mut App) -> Vec<NewGameRequestEvent> {
+        let msgs = app.world().resource::<Messages<NewGameRequestEvent>>();
+        let mut cursor = msgs.get_cursor();
+        cursor.read(msgs).copied().collect()
+    }
+
+    #[test]
+    fn easy_request_dispatches_seed_from_easy_catalog() {
+        let mut app = headless_app();
+        fire_request(&mut app, DifficultyLevel::Easy);
+
+        let events = drain_new_game_events(&mut app);
+        assert_eq!(events.len(), 1);
+        let ev = &events[0];
+        assert!(ev.seed.is_some());
+        assert_eq!(ev.mode, Some(GameMode::Difficulty(DifficultyLevel::Easy)));
+        assert!(!ev.confirmed);
+        // Seed must come from the Easy catalog (non-empty catalog is the test
+        // precondition — the catalog uniqueness test in difficulty_seeds.rs
+        // guards integrity).
+        if !EASY_SEEDS.is_empty() {
+            assert!(
+                EASY_SEEDS.contains(&ev.seed.unwrap()),
+                "seed {:?} not in EASY_SEEDS",
+                ev.seed
+            );
+        }
+    }
+
+    #[test]
+    fn successive_easy_requests_cycle_through_catalog() {
+        let mut app = headless_app();
+        fire_request(&mut app, DifficultyLevel::Easy);
+        fire_request(&mut app, DifficultyLevel::Easy);
+
+        let events = drain_new_game_events(&mut app);
+        assert_eq!(events.len(), 2);
+        // Two successive requests should return different seeds (assuming the
+        // catalog has at least 2 entries — it has 40).
+        if EASY_SEEDS.len() >= 2 {
+            assert_ne!(
+                events[0].seed, events[1].seed,
+                "successive Easy requests should produce different seeds"
+            );
+        }
+    }
+
+    #[test]
+    fn medium_request_dispatches_seed_from_medium_catalog() {
+        let mut app = headless_app();
+        fire_request(&mut app, DifficultyLevel::Medium);
+
+        let events = drain_new_game_events(&mut app);
+        assert_eq!(events.len(), 1);
+        assert_eq!(
+            events[0].mode,
+            Some(GameMode::Difficulty(DifficultyLevel::Medium))
+        );
+        if !MEDIUM_SEEDS.is_empty() {
+            assert!(MEDIUM_SEEDS.contains(&events[0].seed.unwrap()));
+        }
+    }
+
+    #[test]
+    fn random_request_dispatches_some_seed_with_random_mode() {
+        let mut app = headless_app();
+        fire_request(&mut app, DifficultyLevel::Random);
+
+        let events = drain_new_game_events(&mut app);
+        assert_eq!(events.len(), 1);
+        assert!(events[0].seed.is_some(), "Random should always produce Some(seed)");
+        assert_eq!(
+            events[0].mode,
+            Some(GameMode::Difficulty(DifficultyLevel::Random))
+        );
+    }
+
+    #[test]
+    fn different_tier_cursors_are_independent() {
+        let mut app = headless_app();
+        fire_request(&mut app, DifficultyLevel::Easy);
+        fire_request(&mut app, DifficultyLevel::Medium);
+
+        let events = drain_new_game_events(&mut app);
+        assert_eq!(events.len(), 2);
+        // Seeds from different catalogs should differ (they come from different
+        // address ranges by construction of gen_difficulty_seeds).
+        assert_ne!(
+            events[0].seed, events[1].seed,
+            "Easy and Medium should draw from independent catalogs"
+        );
+    }
+}

solitaire_engine/src/events.rs

@@ -129,6 +129,23 @@ pub struct AchievementUnlockedEvent(pub AchievementRecord);
 #[derive(Message, Debug, Clone, Copy, Default)]
 pub struct ManualSyncRequestEvent;
 
+/// Request to open the sync-server setup modal (Connect flow).
+/// Fired by the "Connect" button in the Settings sync section.
+#[derive(Message, Debug, Clone, Copy, Default)]
+pub struct SyncConfigureRequestEvent;
+
+/// Request to disconnect from the current sync backend, clear stored
+/// credentials, and reset to `SyncBackend::Local`. Fired by the "Disconnect"
+/// button in the Settings sync section.
+#[derive(Message, Debug, Clone, Copy, Default)]
+pub struct SyncLogoutRequestEvent;
+
+/// Request to open the account-deletion confirmation modal. Fired by the
+/// "Delete Account" button in the Settings sync section (visible only when
+/// a server backend is configured). Consumed by `SyncSetupPlugin`.
+#[derive(Message, Debug, Clone, Copy, Default)]
+pub struct DeleteAccountRequestEvent;
+
 /// Request to toggle the pause overlay. Fired by the HUD "Pause" button so
 /// the same toggle path runs whether the player presses `Esc` or clicks.
 /// Consumed by `pause_plugin::toggle_pause`, which honours the same drag /
@@ -172,6 +189,23 @@ pub struct StartTimeAttackRequestEvent;
 #[derive(Message, Debug, Clone, Copy, Default)]
 pub struct StartDailyChallengeRequestEvent;
 
+/// Request to open the Play-by-Seed dialog. Fired by the Home overlay
+/// "Play by Seed" mode card. The handler in `play_by_seed_plugin` spawns
+/// a numeric-input modal where the player types a decimal seed and
+/// optionally sees a solver-verified verdict before dealing.
+#[derive(Message, Debug, Clone, Copy, Default)]
+pub struct StartPlayBySeedRequestEvent;
+
+/// Request to start a game at a specific difficulty tier. Fired by the
+/// difficulty section in the home overlay. The handler in `difficulty_plugin`
+/// picks a seed from the corresponding pre-verified catalog (or generates a
+/// random system-time seed for `DifficultyLevel::Random`) and writes a
+/// `NewGameRequestEvent`.
+#[derive(Message, Debug, Clone, Copy)]
+pub struct StartDifficultyRequestEvent {
+    pub level: solitaire_core::game_state::DifficultyLevel,
+}
+
 /// Request to toggle the Stats overlay. Fired by the HUD Menu-popover
 /// "Stats" row alongside the existing `S` accelerator.
 #[derive(Message, Debug, Clone, Copy, Default)]
@@ -212,6 +246,21 @@ pub struct SyncCompleteEvent(pub Result<SyncResponse, String>);
 #[derive(Message, Debug, Clone)]
 pub struct InfoToastEvent(pub String);
 
+/// Generic warning toast message. Spawns a fire-and-forget
+/// [`ToastVariant::Warning`](crate::animation_plugin::ToastVariant) toast.
+///
+/// Distinct from [`InfoToastEvent`] in two ways:
+/// 1. **Variant.** Warning carries the design-system warning border accent,
+///    not the neutral info accent — so the player can distinguish "you might
+///    want to act" from "here's some neutral information".
+/// 2. **No queue.** Warnings are alerts, not a stream. Each event spawns its
+///    own toast immediately rather than waiting for the info queue to drain.
+///
+/// First in-engine driver: daily-challenge expiry warning fired by
+/// `daily_challenge_plugin` when < 30 min from UTC midnight reset.
+#[derive(Message, Debug, Clone)]
+pub struct WarningToastEvent(pub String);
+
 /// Fired by `ProgressPlugin` immediately after awarding XP for a win so the
 /// animation layer can display a "+N XP" toast alongside the win cascade.
 #[derive(Message, Debug, Clone, Copy)]
@@ -234,6 +283,15 @@ pub struct ForfeitEvent;
 #[derive(Message, Debug, Clone, Copy, Default)]
 pub struct ForfeitRequestEvent;
 
+/// Fired when the player clicks "Scan for new themes" in Settings.
+///
+/// Consumed by `handle_scan_themes` in `SettingsPlugin`, which scans
+/// `user_theme_dir()` for `.zip` files, calls `import_theme()` on each
+/// unrecognised archive, refreshes [`crate::theme::ThemeRegistry`], and
+/// fires [`InfoToastEvent`] messages to report results.
+#[derive(Message, Debug, Clone, Copy, Default)]
+pub struct ScanThemesRequestEvent;
+
 /// Fired when the player requests a hint (H key). Carries the source card ID
 /// and destination pile for visual highlighting.
 ///

solitaire_engine/src/game_plugin.rs

@@ -936,6 +936,11 @@ pub fn record_replay_on_win(
         if recording.moves.is_empty() {
             continue;
         }
+        // Recording freezes on win, so the move that triggered the
+        // win condition is the last one in the list. Storing the
+        // index explicitly lets the playback UI read the WIN MOVE
+        // position directly instead of re-deriving it on every render.
+        let win_move_index = recording.moves.len().checked_sub(1);
         let replay = Replay::new(
             game.0.seed,
             game.0.draw_mode.clone(),
@@ -944,7 +949,8 @@ pub fn record_replay_on_win(
             ev.score,
             Utc::now().date_naive(),
             recording.moves.clone(),
-        );
+        )
+        .with_win_move_index(win_move_index);
         let Some(p) = path.as_ref().and_then(|r| r.0.as_deref()) else {
             // No persistence path configured (e.g. tests / minimal Linux
             // containers without dirs::data_dir). The in-memory replay
@@ -984,18 +990,26 @@ pub fn has_legal_moves(game: &GameState) -> bool {
     use solitaire_core::rules::{can_place_on_foundation, can_place_on_tableau};
 
     let mut sources: Vec<Card> = Vec::new();
-    for ty in [PileType::Stock, PileType::Waste] {
+    // Only the top waste card is playable.
-        if let Some(p) = game.piles.get(&ty) {
+    if let Some(p) = game.piles.get(&PileType::Waste)
-            sources.extend(p.cards.iter().cloned());
+        && let Some(top) = p.cards.last()
-        }
-    }
-    for i in 0..7_usize {
-        if let Some(t) = game.piles.get(&PileType::Tableau(i))
-            && let Some(top) = t.cards.last().filter(|c| c.face_up)
     {
         sources.push(top.clone());
     }
+    // Any face-up card in a tableau column can be the base of a movable run.
+    for i in 0..7_usize {
+        if let Some(t) = game.piles.get(&PileType::Tableau(i)) {
+            for card in t.cards.iter().filter(|c| c.face_up) {
+                sources.push(card.clone());
             }
+        }
+    }
+    // Stock cards are face-down and cannot be placed directly; drawing is
+    // only useful if the drawn card can subsequently be placed, which the
+    // waste-card check above already covers for the currently visible card.
+    // Including all stock cards would produce false positives for unplayable
+    // face-down cards (the test has_legal_moves_returns_false_when_stock_only_holds_unplayable_cards
+    // explicitly guards this case).
 
     for card in &sources {
         for slot in 0..4_u8 {
@@ -1058,9 +1072,11 @@ fn check_no_moves(
     }
 
     if !moves_ok && !*already_fired {
-        toast.write(InfoToastEvent(
+        #[cfg(target_os = "android")]
-            "No moves available \u{2014} press D to draw or N for a new game".to_string(),
+        let no_moves_msg = "No moves available \u{2014} tap the stock to draw or start a new game";
-        ));
+        #[cfg(not(target_os = "android"))]
+        let no_moves_msg = "No moves available \u{2014} press D to draw or N for a new game";
+        toast.write(InfoToastEvent(no_moves_msg.to_string()));
         *already_fired = true;
         // Only spawn the overlay if one does not already exist.
         if game_over_screens.is_empty() {
@@ -1724,6 +1740,40 @@ mod tests {
         assert!(!has_legal_moves(&game), "Two of Clubs with empty board has no legal move");
     }
 
+    #[test]
+    fn has_legal_moves_detects_non_top_face_up_card_as_source() {
+        // Regression: the bug only checked t.cards.last() (top face-up card).
+        // If the only legal move involves a face-up card that is NOT the top
+        // card of its column the previous code would return false (softlock)
+        // even though the player can still move that run.
+        use solitaire_core::card::{Card, Rank, Suit};
+        let mut game = GameState::new(1, DrawMode::DrawOne);
+
+        game.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        game.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        for slot in 0..4_u8 {
+            game.piles.get_mut(&PileType::Foundation(slot)).unwrap().cards.clear();
+        }
+        for i in 0..7_usize {
+            game.piles.get_mut(&PileType::Tableau(i)).unwrap().cards.clear();
+        }
+
+        // Tableau 0: face-up Queen of Spades (non-top) + face-up Jack of Hearts on top.
+        // King of Diamonds is on Tableau 1 (empty otherwise), so Queen→King is the
+        // only legal tableau move, and that move targets the Queen which is non-top.
+        let t0 = game.piles.get_mut(&PileType::Tableau(0)).unwrap();
+        t0.cards.push(Card { id: 10, suit: Suit::Spades, rank: Rank::Queen, face_up: true });
+        t0.cards.push(Card { id: 11, suit: Suit::Hearts, rank: Rank::Jack, face_up: true });
+
+        let t1 = game.piles.get_mut(&PileType::Tableau(1)).unwrap();
+        t1.cards.push(Card { id: 12, suit: Suit::Diamonds, rank: Rank::King, face_up: true });
+
+        assert!(
+            has_legal_moves(&game),
+            "Queen (non-top face-up) should be detected as a valid move source onto King",
+        );
+    }
+
     // -----------------------------------------------------------------------
     // Task #57 — Confirm-new-game dialog tests
     // -----------------------------------------------------------------------

solitaire_engine/src/help_plugin.rs

@@ -14,8 +14,8 @@ use crate::ui_modal::{
     ScrimDismissible,
 };
 use crate::ui_theme::{
-    Z_MODAL_PANEL, BORDER_SUBTLE, RADIUS_SM, SPACE_2, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY,
+    BORDER_SUBTLE, HighContrastBorder, RADIUS_SM, SPACE_2, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY,
-    TYPE_CAPTION, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3,
+    TYPE_CAPTION, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, Z_MODAL_PANEL,
 };
 
 /// Marker on the help overlay root node.
@@ -250,9 +250,8 @@ fn spawn_help_screen(commands: &mut Commands, font_res: Option<&FontResource>) {
                         ..default()
                     })
                     .with_children(|line| {
-                        // The hotkey rendered as a small chip with a border —
+                        // Keyboard chip — suppressed on Android (no keyboard).
-                        // visual cue that it's a key reference, not part of
+                        #[cfg(not(target_os = "android"))]
-                        // the description text.
                         line.spawn((
                             Node {
                                 padding: UiRect::axes(VAL_SPACE_2, VAL_SPACE_1),
@@ -263,6 +262,7 @@ fn spawn_help_screen(commands: &mut Commands, font_res: Option<&FontResource>) {
                                 ..default()
                             },
                             BorderColor::all(BORDER_SUBTLE),
+                            HighContrastBorder::with_default(BORDER_SUBTLE),
                         ))
                         .with_children(|chip| {
                             chip.spawn((

solitaire_engine/src/home_plugin.rs

@@ -16,15 +16,15 @@
 use bevy::input::mouse::{MouseScrollUnit, MouseWheel};
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
-use solitaire_core::game_state::DrawMode;
+use solitaire_core::game_state::{DifficultyLevel, DrawMode};
 use solitaire_data::save_settings_to;
 
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
 use crate::daily_challenge_plugin::DailyChallengeResource;
 use crate::events::{
     InfoToastEvent, NewGameRequestEvent, StartChallengeRequestEvent,
-    StartDailyChallengeRequestEvent, StartTimeAttackRequestEvent, StartZenRequestEvent,
+    StartDailyChallengeRequestEvent, StartDifficultyRequestEvent, StartPlayBySeedRequestEvent,
-    ToggleProfileRequestEvent,
+    StartTimeAttackRequestEvent, StartZenRequestEvent, ToggleProfileRequestEvent,
 };
 use crate::font_plugin::FontResource;
 use crate::progress_plugin::ProgressResource;
@@ -38,8 +38,8 @@ use crate::ui_modal::{
     ScrimDismissible,
 };
 use crate::ui_theme::{
-    ACCENT_PRIMARY, BG_ELEVATED, BG_ELEVATED_HI, BORDER_STRONG, BORDER_SUBTLE, RADIUS_MD,
+    ACCENT_PRIMARY, BG_ELEVATED, BG_ELEVATED_HI, BORDER_STRONG, BORDER_SUBTLE, HighContrastBorder,
-    STATE_INFO, TEXT_DISABLED, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG,
+    RADIUS_MD, STATE_INFO, TEXT_DISABLED, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG,
     TYPE_CAPTION, TYPE_DISPLAY, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, Z_MODAL_PANEL,
 };
 
@@ -81,6 +81,27 @@ struct HomeDrawThreeButton;
 #[derive(Component, Debug)]
 struct HomeScrollable;
 
+/// Marker on the "▶ Difficulty" / "▼ Difficulty" toggle button that
+/// expands / collapses the difficulty tier chip row.
+#[derive(Component, Debug)]
+struct HomeDifficultyToggle;
+
+/// Marker on each difficulty tier chip inside the expanded difficulty
+/// section. The wrapped `DifficultyLevel` identifies which tier was
+/// clicked so the handler can fire `StartDifficultyRequestEvent`.
+#[derive(Component, Debug)]
+struct HomeDifficultyChip(DifficultyLevel);
+
+/// Whether the difficulty section is currently expanded. Toggled by
+/// `handle_home_difficulty_toggle` and checked by `spawn_home_screen`
+/// to determine initial render state.
+///
+/// Initialised at plugin startup; `spawn_home_on_launch` upgrades it
+/// to `true` when `settings.last_difficulty` is already set so
+/// returning players see their tier pre-expanded.
+#[derive(Resource, Default, Debug)]
+pub struct DifficultyExpanded(pub bool);
+
 // ---------------------------------------------------------------------------
 // Private mode-card data shape
 // ---------------------------------------------------------------------------
@@ -96,6 +117,7 @@ enum HomeMode {
     Zen,
     Challenge,
     TimeAttack,
+    PlayBySeed,
 }
 
 impl HomeMode {
@@ -107,6 +129,7 @@ impl HomeMode {
             HomeMode::Zen => "Zen Mode",
             HomeMode::Challenge => "Challenge",
             HomeMode::TimeAttack => "Time Attack",
+            HomeMode::PlayBySeed => "Play by Seed",
         }
     }
 
@@ -118,6 +141,7 @@ impl HomeMode {
             HomeMode::Zen => "No timer, no score. Just the cards.",
             HomeMode::Challenge => "Hand-picked hard deals. No undo. Win to advance.",
             HomeMode::TimeAttack => "How many can you finish in ten minutes?",
+            HomeMode::PlayBySeed => "Enter any number to play a specific deal.",
         }
     }
 
@@ -150,6 +174,9 @@ impl HomeMode {
             // ships ▲ (up triangle) but evidently not the sideways
             // siblings.
             HomeMode::TimeAttack => "\u{2192}",
+            // Number sign — ASCII, universally available. Reads as
+            // "a specific number / seed ID".
+            HomeMode::PlayBySeed => "#",
         }
     }
 
@@ -162,6 +189,7 @@ impl HomeMode {
             HomeMode::Zen => "Z",
             HomeMode::Challenge => "X",
             HomeMode::TimeAttack => "T",
+            HomeMode::PlayBySeed => "6",
         }
     }
 
@@ -233,11 +261,14 @@ impl Plugin for HomePlugin {
         // Pre-mark the auto-show as already done in headless mode so the
         // gating system is a permanent no-op for tests.
         app.insert_resource(LaunchHomeShown(!self.auto_show_on_launch))
+            .init_resource::<DifficultyExpanded>()
             .add_message::<NewGameRequestEvent>()
             .add_message::<StartZenRequestEvent>()
             .add_message::<StartChallengeRequestEvent>()
             .add_message::<StartTimeAttackRequestEvent>()
             .add_message::<StartDailyChallengeRequestEvent>()
+            .add_message::<StartPlayBySeedRequestEvent>()
+            .add_message::<StartDifficultyRequestEvent>()
             .add_message::<InfoToastEvent>()
             .add_message::<ToggleProfileRequestEvent>()
             .add_message::<SettingsChangedEvent>()
@@ -245,13 +276,10 @@ impl Plugin for HomePlugin {
             // runs cleanly under MinimalPlugins headless tests too.
             .add_message::<MouseWheel>()
             // `.chain()` because several systems (M-toggle, card click,
-            // cancel button, digit-key shortcut) all read the
+            // cancel button, digit-key shortcut, difficulty handlers)
-            // `HomeScreen` entity and may queue a despawn on it in the
+            // all read the `HomeScreen` entity and may queue a despawn
-            // same tick. Bevy's parallel scheduler would otherwise let
+            // on it in the same tick. Chaining serialises these systems
-            // two of them run simultaneously and double-despawn the
+            // and keeps the despawn deterministic.
-            // entity, panicking when the second command buffer is
-            // applied. Chaining serialises these systems and keeps the
-            // despawn deterministic.
             .add_systems(
                 Update,
                 (
@@ -262,6 +290,8 @@ impl Plugin for HomePlugin {
                     handle_home_cancel_button,
                     handle_home_profile_chip,
                     handle_home_draw_mode_buttons,
+                    handle_home_difficulty_toggle,
+                    handle_home_difficulty_chip_click,
                     handle_home_digit_keys,
                 )
                     .chain(),
@@ -306,6 +336,7 @@ fn spawn_home_on_launch(
     settings: Option<Res<SettingsResource>>,
     daily: Option<Res<DailyChallengeResource>>,
     font_res: Option<Res<FontResource>>,
+    mut diff_expanded: ResMut<DifficultyExpanded>,
 ) {
     if shown.0
         || !splash.is_empty()
@@ -316,6 +347,11 @@ fn spawn_home_on_launch(
         return;
     }
 
+    // Pre-expand the difficulty section when the player has a saved preference.
+    if settings.as_ref().is_some_and(|s| s.0.last_difficulty.is_some()) {
+        diff_expanded.0 = true;
+    }
+
     spawn_home_screen(
         &mut commands,
         build_home_context(
@@ -324,6 +360,7 @@ fn spawn_home_on_launch(
             settings.as_deref(),
             daily.as_deref(),
             font_res.as_deref(),
+            diff_expanded.0,
         ),
     );
     shown.0 = true;
@@ -343,6 +380,7 @@ fn toggle_home_screen(
     daily: Option<Res<DailyChallengeResource>>,
     font_res: Option<Res<FontResource>>,
     screens: Query<Entity, With<HomeScreen>>,
+    diff_expanded: Res<DifficultyExpanded>,
 ) {
     if !keys.just_pressed(KeyCode::KeyM) {
         return;
@@ -358,6 +396,7 @@ fn toggle_home_screen(
                 settings.as_deref(),
                 daily.as_deref(),
                 font_res.as_deref(),
+                diff_expanded.0,
             ),
         );
     }
@@ -373,6 +412,7 @@ fn build_home_context<'a>(
     settings: Option<&SettingsResource>,
     daily: Option<&DailyChallengeResource>,
     font_res: Option<&'a FontResource>,
+    difficulty_expanded: bool,
 ) -> HomeContext<'a> {
     let daily_today = daily.map(|d| {
         let completed_today = progress
@@ -398,6 +438,8 @@ fn build_home_context<'a>(
             .map(|s| s.0.draw_mode.clone())
             .unwrap_or(DrawMode::DrawOne),
         font_res,
+        difficulty_expanded,
+        last_difficulty: settings.and_then(|s| s.0.last_difficulty),
     }
 }
 
@@ -423,6 +465,7 @@ fn handle_home_card_click(
     mut challenge: MessageWriter<StartChallengeRequestEvent>,
     mut time_attack: MessageWriter<StartTimeAttackRequestEvent>,
     mut daily: MessageWriter<StartDailyChallengeRequestEvent>,
+    mut play_by_seed: MessageWriter<StartPlayBySeedRequestEvent>,
     mut info_toast: MessageWriter<InfoToastEvent>,
 ) {
     let level = progress.as_ref().map_or(0, |p| p.0.level);
@@ -457,6 +500,9 @@ fn handle_home_card_click(
             HomeMode::TimeAttack => {
                 time_attack.write(StartTimeAttackRequestEvent);
             }
+            HomeMode::PlayBySeed => {
+                play_by_seed.write(StartPlayBySeedRequestEvent);
+            }
         }
 
         // Close the modal after dispatching the launch event.
@@ -557,6 +603,7 @@ fn handle_home_draw_mode_buttons(
     stats: Option<Res<StatsResource>>,
     daily: Option<Res<DailyChallengeResource>>,
     font_res: Option<Res<FontResource>>,
+    diff_expanded: Res<DifficultyExpanded>,
 ) {
     if screens.is_empty() {
         return;
@@ -600,10 +647,92 @@ fn handle_home_draw_mode_buttons(
             Some(settings),
             daily.as_deref(),
             font_res.as_deref(),
+            diff_expanded.0,
         ),
     );
 }
 
+// ---------------------------------------------------------------------------
+// Difficulty section handlers
+// ---------------------------------------------------------------------------
+
+/// Click on the "▶/▼ Difficulty" header — toggle `DifficultyExpanded` and
+/// repaint the Home modal so the chevron and chip row update. Mirrors
+/// `handle_home_draw_mode_buttons`: despawn + respawn keeps all styling in
+/// `spawn_difficulty_section` rather than scattered across mutation helpers.
+#[allow(clippy::too_many_arguments)]
+fn handle_home_difficulty_toggle(
+    mut commands: Commands,
+    toggles: Query<&Interaction, (With<HomeDifficultyToggle>, Changed<Interaction>)>,
+    screens: Query<Entity, With<HomeScreen>>,
+    mut diff_expanded: ResMut<DifficultyExpanded>,
+    progress: Option<Res<ProgressResource>>,
+    stats: Option<Res<StatsResource>>,
+    settings: Option<Res<SettingsResource>>,
+    daily: Option<Res<DailyChallengeResource>>,
+    font_res: Option<Res<FontResource>>,
+) {
+    if screens.is_empty() {
+        return;
+    }
+    if !toggles.iter().any(|i| *i == Interaction::Pressed) {
+        return;
+    }
+    diff_expanded.0 = !diff_expanded.0;
+    for entity in &screens {
+        commands.entity(entity).despawn();
+    }
+    spawn_home_screen(
+        &mut commands,
+        build_home_context(
+            progress.as_deref(),
+            stats.as_deref(),
+            settings.as_deref(),
+            daily.as_deref(),
+            font_res.as_deref(),
+            diff_expanded.0,
+        ),
+    );
+}
+
+/// Click on a difficulty tier chip — persist `last_difficulty`, fire
+/// `StartDifficultyRequestEvent`, and close the Home modal.
+#[allow(clippy::too_many_arguments)]
+fn handle_home_difficulty_chip_click(
+    mut commands: Commands,
+    chips: Query<(&Interaction, &HomeDifficultyChip), Changed<Interaction>>,
+    screens: Query<Entity, With<HomeScreen>>,
+    mut difficulty_ev: MessageWriter<StartDifficultyRequestEvent>,
+    mut settings: Option<ResMut<SettingsResource>>,
+    storage_path: Option<Res<SettingsStoragePath>>,
+    mut changed: MessageWriter<SettingsChangedEvent>,
+) {
+    if screens.is_empty() {
+        return;
+    }
+    let Some((_, chip)) = chips.iter().find(|(i, _)| **i == Interaction::Pressed) else {
+        return;
+    };
+    let level = chip.0;
+
+    if let Some(s) = settings.as_mut() {
+        s.0.last_difficulty = Some(level);
+        if let Some(p) = storage_path
+            && let Some(path) = p.0.as_deref()
+            && let Err(e) = save_settings_to(path, &s.0)
+        {
+            warn!("home: failed to persist last_difficulty: {e}");
+        }
+        changed.write(SettingsChangedEvent(s.0.clone()));
+    }
+
+    difficulty_ev.write(StartDifficultyRequestEvent { level });
+
+    for entity in &screens {
+        commands.entity(entity).despawn();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Digit-key shortcuts (1-5) — modal-scoped
 // ---------------------------------------------------------------------------
@@ -619,6 +748,7 @@ fn digit_to_home_mode(key: KeyCode) -> Option<HomeMode> {
         KeyCode::Digit3 => Some(HomeMode::Zen),
         KeyCode::Digit4 => Some(HomeMode::Challenge),
         KeyCode::Digit5 => Some(HomeMode::TimeAttack),
+        KeyCode::Digit6 => Some(HomeMode::PlayBySeed),
         _ => None,
     }
 }
@@ -646,6 +776,7 @@ fn handle_home_digit_keys(
     mut challenge: MessageWriter<StartChallengeRequestEvent>,
     mut time_attack: MessageWriter<StartTimeAttackRequestEvent>,
     mut daily: MessageWriter<StartDailyChallengeRequestEvent>,
+    mut play_by_seed: MessageWriter<StartPlayBySeedRequestEvent>,
 ) {
     // Modal-scoped: do nothing when the Mode Launcher isn't open.
     if screens.is_empty() {
@@ -658,6 +789,7 @@ fn handle_home_digit_keys(
         KeyCode::Digit3,
         KeyCode::Digit4,
         KeyCode::Digit5,
+        KeyCode::Digit6,
     ]
     .into_iter()
     .find(|k| keys.just_pressed(*k))
@@ -687,6 +819,9 @@ fn handle_home_digit_keys(
         HomeMode::TimeAttack => {
             time_attack.write(StartTimeAttackRequestEvent);
         }
+        HomeMode::PlayBySeed => {
+            play_by_seed.write(StartPlayBySeedRequestEvent);
+        }
     }
 
     // Close the modal after dispatching the launch event — same shape as
@@ -717,6 +852,11 @@ struct HomeContext<'a> {
     daily_today: Option<DailyToday>,
     draw_mode: DrawMode,
     font_res: Option<&'a FontResource>,
+    /// Whether the difficulty section header is currently expanded.
+    difficulty_expanded: bool,
+    /// The last difficulty tier the player selected (persisted in Settings).
+    /// When `Some`, that tier's chip is highlighted.
+    last_difficulty: Option<DifficultyLevel>,
 }
 
 /// Today's daily-challenge metadata as the Home picker needs it. Only
@@ -784,10 +924,13 @@ fn spawn_home_screen(commands: &mut Commands, ctx: HomeContext<'_>) {
                     HomeMode::Zen,
                     HomeMode::Challenge,
                     HomeMode::TimeAttack,
+                    HomeMode::PlayBySeed,
                 ] {
                     spawn_mode_card(grid, mode, &ctx);
                 }
             });
+
+            spawn_difficulty_section(body, &ctx);
         });
 
         spawn_modal_actions(card, |actions| {
@@ -840,6 +983,7 @@ fn spawn_home_header_chips(parent: &mut ChildSpawnerCommands, ctx: &HomeContext<
             },
             BackgroundColor(BG_ELEVATED),
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
         ))
         .with_children(|row| {
             for (label, value) in [
@@ -943,12 +1087,108 @@ fn spawn_draw_mode_chip<M: Component>(
             },
             BackgroundColor(bg),
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
         ))
         .with_children(|c| {
             c.spawn((Text::new(label.to_string()), font.clone(), TextColor(fg)));
         });
 }
 
+/// Collapsible difficulty-tier section injected below the mode tile grid.
+///
+/// Structure:
+/// ```text
+/// ▶ Difficulty        ← HomeDifficultyToggle (Button, row)
+/// [Easy] [Medium] [Hard] [Expert] [GM] [Random]   ← visible only when expanded
+/// ```
+///
+/// The toggle header despawns + respawns the home screen (same pattern as
+/// the draw-mode toggle) so the chevron direction and chip row visibility
+/// update without Visibility component surgery.
+fn spawn_difficulty_section(parent: &mut ChildSpawnerCommands, ctx: &HomeContext<'_>) {
+    let font_handle = ctx.font_res.map(|f| f.0.clone()).unwrap_or_default();
+    let font_label = TextFont { font: font_handle.clone(), font_size: TYPE_BODY, ..default() };
+    let font_chip = TextFont { font: font_handle, font_size: TYPE_CAPTION, ..default() };
+
+    let chevron = if ctx.difficulty_expanded { "▼" } else { "▶" };
+
+    // Header row — click to toggle expand/collapse.
+    parent
+        .spawn((
+            HomeDifficultyToggle,
+            Button,
+            Node {
+                flex_direction: FlexDirection::Row,
+                align_items: AlignItems::Center,
+                column_gap: VAL_SPACE_2,
+                padding: UiRect::axes(Val::Px(0.0), VAL_SPACE_1),
+                ..default()
+            },
+        ))
+        .with_children(|row| {
+            row.spawn((
+                Text::new(chevron),
+                font_label.clone(),
+                TextColor(TEXT_SECONDARY),
+            ));
+            row.spawn((
+                Text::new("Difficulty"),
+                font_label.clone(),
+                TextColor(TEXT_SECONDARY),
+            ));
+        });
+
+    // Tier chips — only rendered when expanded.
+    if ctx.difficulty_expanded {
+        parent
+            .spawn(Node {
+                flex_direction: FlexDirection::Row,
+                flex_wrap: FlexWrap::Wrap,
+                row_gap: VAL_SPACE_2,
+                column_gap: VAL_SPACE_2,
+                width: Val::Percent(100.0),
+                ..default()
+            })
+            .with_children(|row| {
+                for level in [
+                    DifficultyLevel::Easy,
+                    DifficultyLevel::Medium,
+                    DifficultyLevel::Hard,
+                    DifficultyLevel::Expert,
+                    DifficultyLevel::Grandmaster,
+                    DifficultyLevel::Random,
+                ] {
+                    let active = ctx.last_difficulty == Some(level);
+                    let (bg, fg) = if active {
+                        (ACCENT_PRIMARY, BG_ELEVATED)
+                    } else {
+                        (BG_ELEVATED_HI, TEXT_PRIMARY)
+                    };
+                    row.spawn((
+                        HomeDifficultyChip(level),
+                        Button,
+                        Node {
+                            padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_1),
+                            border: UiRect::all(Val::Px(1.0)),
+                            border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+                            ..default()
+                        },
+                        BackgroundColor(bg),
+                        BorderColor::all(BORDER_SUBTLE),
+                        HighContrastBorder::with_default(BORDER_SUBTLE),
+                    ))
+                    .with_children(|c| {
+                        c.spawn((
+                            Text::new(level.label()),
+                            font_chip.clone(),
+                            TextColor(fg),
+                        ));
+                    });
+                }
+            });
+    }
+}
+
 /// Compact decimal formatter: `1234567` → `"1.2M"`, `12345` → `"12.3K"`,
 /// otherwise the raw number with thousands separators. Keeps chip text
 /// short enough to fit a 3-up header strip without wrapping.
@@ -997,6 +1237,7 @@ fn home_mode_focus_order(mode: HomeMode) -> i32 {
         HomeMode::Zen => 2,
         HomeMode::Challenge => 3,
         HomeMode::TimeAttack => 4,
+        HomeMode::PlayBySeed => 5,
     }
 }
 
@@ -1144,8 +1385,8 @@ fn spawn_mode_card(
                 ));
 
                 if unlocked {
-                    // Hotkey chip — same look as the kbd-chip rows used
+                    // Hotkey chip — suppressed on Android (touch builds have no keyboard).
-                    // elsewhere so accelerators read consistently.
+                    #[cfg(not(target_os = "android"))]
                     row.spawn((
                         Node {
                             padding: UiRect::axes(VAL_SPACE_2, VAL_SPACE_1),
@@ -1156,6 +1397,7 @@ fn spawn_mode_card(
                             ..default()
                         },
                         BorderColor::all(BORDER_SUBTLE),
+                        HighContrastBorder::with_default(BORDER_SUBTLE),
                     ))
                     .with_children(|chip| {
                         chip.spawn((
@@ -1399,13 +1641,14 @@ mod tests {
             HomeMode::Zen,
             HomeMode::Challenge,
             HomeMode::TimeAttack,
+            HomeMode::PlayBySeed,
         ] {
             assert!(
                 modes.contains(&expected),
                 "missing card for {expected:?}; found {modes:?}"
             );
         }
-        assert_eq!(modes.len(), 5, "exactly five cards expected");
+        assert_eq!(modes.len(), 6, "exactly six cards expected");
     }
 
     #[test]
@@ -1597,7 +1840,7 @@ mod tests {
             .map(|(c, f)| (c.0, *f))
             .collect();
 
-        assert_eq!(cards.len(), 5, "all five cards must carry a Focusable");
+        assert_eq!(cards.len(), 6, "all six cards must carry a Focusable");
         for (mode, focusable) in &cards {
             assert_eq!(
                 focusable.group,
@@ -1623,7 +1866,7 @@ mod tests {
 
         for (mode, disabled) in states {
             match mode {
-                HomeMode::Classic | HomeMode::Daily => assert!(
+                HomeMode::Classic | HomeMode::Daily | HomeMode::PlayBySeed => assert!(
                     !disabled,
                     "{mode:?} must not be Disabled at level 0 (it's never locked)"
                 ),

solitaire_engine/src/hud_plugin.rs

@@ -7,6 +7,7 @@
 //! without a separate tick system.
 
 use bevy::prelude::*;
+use bevy::window::WindowResized;
 use solitaire_core::card::Suit;
 use solitaire_core::game_state::{DrawMode, GameMode};
 use solitaire_core::pile::PileType;
@@ -17,9 +18,11 @@ use crate::daily_challenge_plugin::DailyChallengeResource;
 use crate::progress_plugin::ProgressResource;
 use crate::settings_plugin::SettingsResource;
 use crate::layout::HUD_BAND_HEIGHT;
+use crate::safe_area::{SafeAreaAnchoredTop, SafeAreaInsets};
+use crate::ui_theme::SPACE_2;
 use crate::ui_theme::{
     scaled_duration, ACCENT_PRIMARY, ACCENT_SECONDARY, BG_ELEVATED, BG_ELEVATED_HI,
-    BG_ELEVATED_PRESSED, BG_HUD_BAND, BORDER_SUBTLE, MOTION_SCORE_PULSE_SECS,
+    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,
@@ -239,6 +242,11 @@ pub struct PauseButton;
 #[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;
+
 /// 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.
@@ -273,6 +281,16 @@ pub struct MenuButton;
 #[derive(Component, Debug)]
 pub struct MenuPopover;
 
+/// 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)]
@@ -322,11 +340,15 @@ impl Plugin for HudPlugin {
             .add_message::<WinStreakMilestoneEvent>()
             .init_resource::<PreviousScore>()
             .init_resource::<HudActionFade>()
+            // 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))
             .add_systems(Update, update_hud.after(GameMutation))
             .add_systems(Update, update_won_previously.after(GameMutation))
             .add_systems(Update, announce_auto_complete.after(GameMutation))
             .add_systems(Update, update_selection_hud)
+            .add_systems(Update, update_hud_typography)
             .add_systems(
                 Update,
                 (
@@ -350,10 +372,13 @@ impl Plugin for HudPlugin {
                     handle_undo_button,
                     handle_pause_button,
                     handle_help_button,
+                    handle_hint_button,
                     handle_modes_button,
                     handle_mode_option_click,
+                    handle_modes_backdrop_click,
                     handle_menu_button,
                     handle_menu_option_click,
+                    handle_menu_backdrop_click,
                     paint_action_buttons,
                 ),
             )
@@ -376,11 +401,13 @@ impl Plugin for HudPlugin {
 /// bottom edge lines up exactly with the top edge of the highest
 /// playable card. The fill is `BG_HUD_BAND` — midnight purple at 0.70
 /// alpha, so the green felt reads through subtly.
-fn spawn_hud_band(mut commands: Commands) {
+fn spawn_hud_band(insets: Option<Res<SafeAreaInsets>>, mut commands: Commands) {
+    const BASE_TOP: f32 = 0.0;
+    let top_inset = insets.as_deref().copied().unwrap_or_default().top;
     commands.spawn((
         Node {
             position_type: PositionType::Absolute,
-            top: Val::Px(0.0),
+            top: Val::Px(BASE_TOP + top_inset),
             left: Val::Px(0.0),
             width: Val::Percent(100.0),
             height: Val::Px(HUD_BAND_HEIGHT),
@@ -391,6 +418,7 @@ fn spawn_hud_band(mut commands: Commands) {
         // paint on top, but above the card sprites (which are 2D-world
         // entities and rendered behind UI regardless).
         ZIndex(Z_HUD - 1),
+        SafeAreaAnchoredTop { base_top: BASE_TOP },
     ));
 }
 
@@ -413,7 +441,12 @@ fn spawn_hud_band(mut commands: Commands) {
 /// 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.
-fn spawn_hud(font_res: Option<Res<FontResource>>, mut commands: Commands) {
+fn spawn_hud(
+    font_res: Option<Res<FontResource>>,
+    insets: Option<Res<SafeAreaInsets>>,
+    mut commands: Commands,
+) {
+    let top_inset = insets.as_deref().copied().unwrap_or_default().top;
     let font_handle = font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default();
     let font_score = TextFont {
         font: font_handle.clone(),
@@ -434,6 +467,16 @@ fn spawn_hud(font_res: Option<Res<FontResource>>, mut commands: Commands) {
     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()
     };
@@ -443,12 +486,21 @@ fn spawn_hud(font_res: Option<Res<FontResource>>, mut commands: Commands) {
             Node {
                 position_type: PositionType::Absolute,
                 left: VAL_SPACE_3,
-                top: VAL_SPACE_2,
+                top: Val::Px(SPACE_2 + top_inset),
                 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 },
         ))
         .with_children(|hud| {
             // Tier 1 — primary readouts. Score is the protagonist (HEADLINE);
@@ -568,94 +620,83 @@ fn spawn_hud(font_res: Option<Res<FontResource>>, mut commands: Commands) {
 /// 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.
-fn spawn_action_buttons(font_res: Option<Res<FontResource>>, mut commands: Commands) {
+fn spawn_action_buttons(
+    font_res: Option<Res<FontResource>>,
+    insets: Option<Res<SafeAreaInsets>>,
+    mut commands: Commands,
+) {
+    let top_inset = insets.as_deref().copied().unwrap_or_default().top;
+    #[cfg(not(target_os = "android"))]
     let font = TextFont {
         font: font_res.as_ref().map(|f| f.0.clone()).unwrap_or_default(),
-        // TYPE_BODY (14.0) — was a hardcoded `16.0` until the
-        // top-bar-overlap fix. Aligns with the rest of `hud_plugin`'s
-        // text (which already routes through the `TYPE_*` tokens) and
-        // reclaims horizontal space so the action button row doesn't
-        // collide with the left-anchored HUD column at narrow window
-        // widths.
         font_size: TYPE_BODY,
         ..default()
     };
+    // Android labels use only FiraMono-safe glyphs (≡ ← ‖ → ▾), so the same
+    // embedded font works — no system font fallback required.
+    #[cfg(target_os = "android")]
+    let font = TextFont { font_size: TYPE_BODY, ..default() };
+
+    // On Android, 7 text-labelled buttons at 48 dp each wrap to two rows on
+    // a 411 dp phone. Use compact Unicode symbols and tighter gaps so all 7
+    // fit in a single row (7×44 + 6×4 = 332 dp, well within a 90%-wide band
+    // of 370 dp). On desktop, keep the descriptive text labels.
+    #[cfg(target_os = "android")]
+    let (max_width, col_gap, row_gap_val) =
+        (Val::Percent(90.0), Val::Px(4.0), Val::Px(4.0));
+    #[cfg(not(target_os = "android"))]
+    let (max_width, col_gap, row_gap_val) =
+        (Val::Percent(65.0), VAL_SPACE_2, VAL_SPACE_2);
+
+    #[cfg(target_os = "android")]
+    let labels = (
+        /* menu */  "\u{2261}",  // ≡  identical-to (hamburger look-alike, in FiraMono)
+        /* undo */  "\u{2190}",  // ←  leftwards arrow (in FiraMono)
+        /* pause */ "\u{2016}",  // ‖  double vertical line (in FiraMono general-punct)
+        /* help */  "?",
+        /* hint */  "\u{2192}",  // →  rightwards arrow (in FiraMono)
+        /* modes */ "\u{25BE}",  // ▾  small down-pointing triangle (in FiraMono)
+        /* new */   "+",
+    );
+    #[cfg(not(target_os = "android"))]
+    let labels = (
+        "Menu \u{25BE}",
+        "Undo",
+        "Pause",
+        "Help",
+        "Hint",
+        "Modes \u{25BE}",
+        "New Game",
+    );
+
     commands
         .spawn((
             Node {
                 position_type: PositionType::Absolute,
                 right: VAL_SPACE_3,
-                top: VAL_SPACE_2,
+                top: Val::Px(SPACE_2 + top_inset),
                 flex_direction: FlexDirection::Row,
-                column_gap: VAL_SPACE_2,
+                max_width,
+                flex_wrap: FlexWrap::Wrap,
+                justify_content: JustifyContent::FlexEnd,
+                column_gap: col_gap,
+                row_gap: row_gap_val,
                 align_items: AlignItems::Center,
                 ..default()
             },
             ZIndex(Z_HUD),
+            SafeAreaAnchoredTop { base_top: SPACE_2 },
         ))
         .with_children(|row| {
-            // Menu and Modes don't have a single hotkey accelerator
+            // The trailing `order` argument feeds `Focusable { group: Hud, order }`
-            // (each row inside their popover has its own); their button
+            // so Tab cycles the action bar in visual reading order.
-            // labels carry the dropdown chevron in lieu of a key chip.
+            spawn_action_button(row, MenuButton,   labels.0, None,         "Open Stats, Achievements, Profile, Settings, or Leaderboard.", &font, 0);
-            //
+            spawn_action_button(row, UndoButton,   labels.1, Some("U"),    "Take back your last move. Costs points and blocks No Undo.", &font, 1);
-            // The trailing `order` argument is the per-button index in
+            spawn_action_button(row, PauseButton,  labels.2, Some("Esc"),  "Pause the game and freeze the timer.", &font, 2);
-            // visual reading order (left → right). It feeds
+            spawn_action_button(row, HelpButton,   labels.3, Some("F1"),   "Show controls, rules, and keyboard shortcuts.", &font, 3);
-            // `Focusable { group: Hud, order }` so Tab cycles the action
+            spawn_action_button(row, HintButton,   labels.4, Some("H"),    "Highlight a suggested move. Cycles through alternatives on repeat taps.", &font, 4);
-            // bar in the same order the eye scans it.
+            spawn_action_button(row, ModesButton,  labels.5, None,         "Switch modes: Classic, Daily, Zen, Challenge, Time Attack.", &font, 5);
-            spawn_action_button(
+            spawn_action_button(row, NewGameButton,labels.6, Some("N"),    "Start a fresh deal. Confirms first if a game is in progress.", &font, 6);
-                row,
-                MenuButton,
-                "Menu \u{25BE}",
-                None,
-                "Open Stats, Achievements, Profile, Settings, or Leaderboard.",
-                &font,
-                0,
-            );
-            spawn_action_button(
-                row,
-                UndoButton,
-                "Undo",
-                Some("U"),
-                "Take back your last move. Costs points and blocks No Undo.",
-                &font,
-                1,
-            );
-            spawn_action_button(
-                row,
-                PauseButton,
-                "Pause",
-                Some("Esc"),
-                "Pause the game and freeze the timer.",
-                &font,
-                2,
-            );
-            spawn_action_button(
-                row,
-                HelpButton,
-                "Help",
-                Some("F1"),
-                "Show controls, rules, and keyboard shortcuts.",
-                &font,
-                3,
-            );
-            spawn_action_button(
-                row,
-                ModesButton,
-                "Modes \u{25BE}",
-                None,
-                "Switch modes: Classic, Daily, Zen, Challenge, Time Attack.",
-                &font,
-                4,
-            );
-            spawn_action_button(
-                row,
-                NewGameButton,
-                "New Game",
-                Some("N"),
-                "Start a fresh deal. Confirms first if a game is in progress.",
-                &font,
-                5,
-            );
         });
 }
 
@@ -681,32 +722,42 @@ fn spawn_action_button<M: Component>(
     font: &TextFont,
     order: i32,
 ) {
+    // 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. Force the hint
+    // off on Android; the chevrons on Menu/Modes remain because they
+    // indicate dropdown behaviour and still apply on touch.
+    #[cfg(target_os = "android")]
+    let hotkey: Option<&'static str> = None;
+
     let hotkey_font = TextFont {
         font: font.font.clone(),
         font_size: TYPE_CAPTION,
         ..default()
     };
+    // On Android, use tighter padding and a slightly smaller min-size so all
+    // 7 icon-label buttons fit in one row on a ~411 dp phone. 44 dp ≥
+    // Apple's minimum touch target; padding of 4 dp each side keeps the icon
+    // centred with room to breathe. On desktop, keep the comfortable 48 dp
+    // floor and 8 dp side padding.
+    #[cfg(target_os = "android")]
+    let (pad, min_w, min_h) = (UiRect::axes(Val::Px(4.0), Val::Px(4.0)), Val::Px(44.0), Val::Px(44.0));
+    #[cfg(not(target_os = "android"))]
+    let (pad, min_w, min_h) = (UiRect::axes(VAL_SPACE_2, VAL_SPACE_2), Val::Px(48.0), Val::Px(48.0));
+
     row.spawn((
         marker,
         ActionButton,
         Button,
         Tooltip::new(tooltip),
-        // Joins the `Hud` focus group at the supplied order so Tab
-        // cycles HUD buttons left-to-right under Phase 2. The HUD focus
-        // ring still only engages when a HUD button is hovered (or in
-        // future phases, when the player explicitly switches groups);
-        // the marker just declares membership.
         Focusable {
             group: FocusGroup::Hud,
             order,
         },
         Node {
-            // Horizontal padding stepped down from VAL_SPACE_3 to
+            padding: pad,
-            // VAL_SPACE_2 to reclaim ~96px across the 6-button row at
+            min_width: min_w,
-            // narrow window widths (see top-bar-overlap fix in the
+            min_height: min_h,
-            // companion commit). Vertical padding stays at VAL_SPACE_2
-            // so button height tracks the rest of the chrome band.
-            padding: UiRect::axes(VAL_SPACE_2, VAL_SPACE_2),
             justify_content: JustifyContent::Center,
             align_items: AlignItems::Center,
             border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
@@ -715,6 +766,7 @@ fn spawn_action_button<M: Component>(
         },
         BackgroundColor(ACTION_BTN_IDLE),
         BorderColor::all(BORDER_SUBTLE),
+        HighContrastBorder::with_default(BORDER_SUBTLE),
     ))
     .with_children(|b| {
         b.spawn((Text::new(label), font.clone(), TextColor(TEXT_PRIMARY)));
@@ -776,12 +828,43 @@ fn handle_help_button(
     }
 }
 
+fn handle_hint_button(
+    interaction_query: Query<&Interaction, (With<HintButton>, Changed<Interaction>)>,
+    paused: Option<Res<crate::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 {
+            #[cfg(target_os = "android")]
+            let won_msg = "Game won! Tap New Game to play again";
+            #[cfg(not(target_os = "android"))]
+            let won_msg = "Game won! Press N for a new game";
+            info_toast.write(InfoToastEvent(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.0);
+        }
+    }
+}
+
 /// 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.
 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>>,
@@ -795,6 +878,9 @@ fn handle_modes_button(
     }
     if let Ok(entity) = popovers.single() {
         commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
     } else {
         spawn_modes_popover(
             &mut commands,
@@ -895,6 +981,23 @@ fn spawn_modes_popover(
                     });
             }
         });
+
+    // Fullscreen transparent backdrop at Z_HUD+4 (below the popover at
+    // Z_HUD+5) so tapping outside the panel 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 + 4),
+    ));
 }
 
 /// Dispatches the click on a popover row to the matching request event,
@@ -908,6 +1011,7 @@ fn spawn_modes_popover(
 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>,
@@ -940,8 +1044,12 @@ fn handle_mode_option_click(
         }
     }
     if clicked_any
-        && let Ok(entity) = popovers.single() {
+        && let Ok(entity) = popovers.single()
+    {
         commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
     }
 }
 
@@ -951,6 +1059,7 @@ fn handle_mode_option_click(
 fn handle_menu_button(
     interaction_query: Query<&Interaction, (With<MenuButton>, Changed<Interaction>)>,
     popovers: Query<Entity, With<MenuPopover>>,
+    backdrops: Query<Entity, With<MenuPopoverBackdrop>>,
     font_res: Option<Res<FontResource>>,
     mut commands: Commands,
 ) {
@@ -962,6 +1071,9 @@ fn handle_menu_button(
     }
     if let Ok(entity) = popovers.single() {
         commands.entity(entity).despawn();
+        for e in &backdrops {
+            commands.entity(e).despawn();
+        }
     } else {
         spawn_menu_popover(&mut commands, font_res.as_deref());
     }
@@ -1049,6 +1161,23 @@ fn spawn_menu_popover(commands: &mut Commands, font_res: Option<&FontResource>)
                     });
             }
         });
+
+    // 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 + 4),
+    ));
 }
 
 /// Dispatches the click on a menu row to the matching toggle event,
@@ -1057,6 +1186,7 @@ fn spawn_menu_popover(commands: &mut Commands, font_res: Option<&FontResource>)
 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>,
@@ -1091,6 +1221,43 @@ fn handle_menu_option_click(
     if clicked_any
         && let Ok(entity) = popovers.single() {
             commands.entity(entity).despawn();
+            for e in &backdrops {
+                commands.entity(e).despawn();
+            }
+        }
+}
+
+/// Despawns the [`ModesPopover`] and its backdrop when the player taps
+/// anywhere outside the panel.
+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).
+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();
     }
 }
 
@@ -1740,6 +1907,7 @@ fn update_hud(
                 GameMode::Zen => "ZEN".to_string(),
                 GameMode::Challenge => "CHALLENGE".to_string(),
                 GameMode::TimeAttack => "TIME ATTACK".to_string(),
+                GameMode::Difficulty(level) => level.label().to_uppercase(),
             };
         }
 
@@ -1936,6 +2104,46 @@ pub fn challenge_time_color(remaining: u64) -> Color {
     }
 }
 
+/// 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>)>;
+
+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;
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -2441,6 +2649,7 @@ mod tests {
             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),
         ] {
@@ -2549,6 +2758,10 @@ mod tests {
             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."
@@ -2668,14 +2881,15 @@ mod tests {
     fn hud_button_order_matches_spawn_order() {
         let mut app = headless_app();
         // Visual reading order (left → right): Menu, Undo, Pause, Help,
-        // Modes, New Game. Their `order` fields must be 0..=5 in that
+        // Hint, Modes, New Game. Their `order` fields must be 0..=6 in
-        // order so Tab cycles them as the player reads them.
+        // 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::<ModesButton>(&mut app).order, 4);
+        assert_eq!(focusable_for::<HintButton>(&mut app).order, 4);
-        assert_eq!(focusable_for::<NewGameButton>(&mut app).order, 5);
+        assert_eq!(focusable_for::<ModesButton>(&mut app).order, 5);
+        assert_eq!(focusable_for::<NewGameButton>(&mut app).order, 6);
     }
 
     #[test]

solitaire_engine/src/input_plugin.rs

@@ -23,7 +23,9 @@ use bevy::input::touch::{TouchInput, TouchPhase, Touches};
 use bevy::input::ButtonInput;
 use bevy::math::{Vec2, Vec3};
 use bevy::prelude::*;
-use bevy::window::{MonitorSelection, PrimaryWindow, WindowMode};
+use bevy::window::PrimaryWindow;
+#[cfg(not(target_os = "android"))]
+use bevy::window::{MonitorSelection, WindowMode};
 use solitaire_core::card::{Card, Suit};
 use solitaire_core::game_state::GameState;
 use solitaire_core::pile::PileType;
@@ -31,11 +33,9 @@ use solitaire_core::rules::{can_place_on_foundation, can_place_on_tableau};
 
 use crate::card_animation::tuning::AnimationTuning;
 use crate::card_animation::{CardAnimation, MotionCurve};
-use crate::card_plugin::{
+use crate::card_plugin::{CardEntity, HintHighlight, HintHighlightTimer, STACK_FAN_FRAC};
-    CardEntity, HintHighlight, HintHighlightTimer, STACK_FAN_FRAC, TABLEAU_FACEDOWN_FAN_FRAC,
+use crate::radial_menu::RightClickRadialState;
-    TABLEAU_FAN_FRAC,
+use crate::ui_theme::{MOTION_DRAG_REJECT_SECS, STATE_SUCCESS, STATE_WARNING};
-};
-use crate::ui_theme::{MOTION_DRAG_REJECT_SECS, STATE_WARNING};
 use solitaire_core::game_state::DrawMode;
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
 use crate::events::{
@@ -105,12 +105,16 @@ impl Plugin for InputPlugin {
                     // Touch drag pipeline (parallel path through DragState).
                     touch_start_drag,
                     touch_follow_drag,
+                    handle_double_tap, // before touch_end_drag: reads drag state pre-clear
                     touch_end_drag.before(GameMutation),
                 )
                     .chain(),
             )
-            .add_systems(Update, handle_fullscreen)
+            .add_systems(Update, reset_hint_cycle_on_state_change);
-            .add_systems(Update, reset_hint_cycle_on_state_change)
+        // F11 fullscreen toggle is desktop-only; Android windows are always full-screen.
+        #[cfg(not(target_os = "android"))]
+        app.add_systems(Update, handle_fullscreen);
+        app
             // Async hint pipeline: state-change drop runs before the
             // poll system so a move applied this frame cancels any
             // in-flight task before its result can be surfaced.
@@ -423,6 +427,7 @@ fn reset_hint_cycle_on_state_change(
 
 /// `F11` toggles between borderless-fullscreen and windowed mode.
 /// Not gated by the pause flag — the player can always resize the window.
+#[cfg(not(target_os = "android"))]
 fn handle_fullscreen(
     keys: Res<ButtonInput<KeyCode>>,
     mut windows: Query<&mut Window, With<PrimaryWindow>>,
@@ -515,8 +520,10 @@ fn handle_touch_stock_tap(
 /// Begins a mouse drag: records the press position and the cards that would be
 /// dragged. Cards are **not** elevated yet — that happens in [`follow_drag`]
 /// once the drag threshold is crossed.
+#[allow(clippy::too_many_arguments)]
 fn start_drag(
     buttons: Res<ButtonInput<MouseButton>>,
+    touches: Option<Res<Touches>>,
     paused: Option<Res<PausedResource>>,
     windows: Query<&Window, With<PrimaryWindow>>,
     cameras: Query<(&Camera, &GlobalTransform)>,
@@ -531,6 +538,15 @@ fn start_drag(
     if !buttons.just_pressed(MouseButton::Left) || !drag.is_idle() {
         return;
     }
+    // On platforms where Winit simulates a MouseButton::Left press from the
+    // first touch, this guard ensures touch_start_drag (which runs after this
+    // system) claims the drag state instead of the mouse path. Without it the
+    // card is tracked via cursor_world (updated from the simulated mouse
+    // position) rather than the Touches resource, which can be one frame
+    // behind the actual finger position on Android.
+    if touches.as_ref().is_some_and(|t| t.iter_just_pressed().next().is_some()) {
+        return;
+    }
     let Some(layout) = layout else { return };
     let Some(world) = cursor_world(&windows, &cameras) else { return };
 
@@ -607,7 +623,7 @@ fn follow_drag(
 
     // Move cards to the cursor.
     let bottom_pos = world + drag.cursor_offset;
-    let fan = -layout.0.card_size.y * TABLEAU_FAN_FRAC;
+    let fan = -layout.0.card_size.y * layout.0.tableau_fan_frac;
 
     for (i, &id) in drag.cards.iter().enumerate() {
         if let Some((_, mut transform, _)) =
@@ -868,7 +884,7 @@ fn touch_follow_drag(
     }
 
     let bottom_pos = world + drag.cursor_offset;
-    let fan = -layout.0.card_size.y * TABLEAU_FAN_FRAC;
+    let fan = -layout.0.card_size.y * layout.0.tableau_fan_frac;
 
     for (i, &id) in drag.cards.iter().enumerate() {
         if let Some((_, mut transform, _)) =
@@ -1040,8 +1056,8 @@ fn point_in_rect(point: Vec2, center: Vec2, size: Vec2) -> bool {
 /// Where a card at `stack_index` in pile `pile` would be rendered.
 ///
 /// For tableau columns the per-card fan step depends on the face-up state of
-/// every preceding card — face-down cards step by `TABLEAU_FACEDOWN_FAN_FRAC`,
+/// every preceding card — face-down cards step by `layout.tableau_facedown_fan_frac`,
-/// face-up cards by `TABLEAU_FAN_FRAC`. Mirrors `card_plugin::card_positions`
+/// face-up cards by `layout.tableau_fan_frac`. Mirrors `card_plugin::card_positions`
 /// exactly; any drift creates an offset between the visible card face and
 /// where clicks land.
 fn card_position(game: &GameState, layout: &Layout, pile: &PileType, stack_index: usize) -> Vec2 {
@@ -1051,9 +1067,9 @@ fn card_position(game: &GameState, layout: &Layout, pile: &PileType, stack_index
         if let Some(pile_cards) = game.piles.get(pile) {
             for card in pile_cards.cards.iter().take(stack_index) {
                 let step = if card.face_up {
-                    TABLEAU_FAN_FRAC
+                    layout.tableau_fan_frac
                 } else {
-                    TABLEAU_FACEDOWN_FAN_FRAC
+                    layout.tableau_facedown_fan_frac
                 };
                 y_offset -= layout.card_size.y * step;
             }
@@ -1188,7 +1204,7 @@ fn pile_drop_rect(pile: &PileType, layout: &Layout, game: &GameState) -> (Vec2,
     if matches!(pile, PileType::Tableau(_)) {
         let card_count = game.piles.get(pile).map_or(0, |p| p.cards.len());
         if card_count > 1 {
-            let fan = -layout.card_size.y * TABLEAU_FAN_FRAC;
+            let fan = -layout.card_size.y * layout.tableau_fan_frac;
             let bottom_card_center_y = center.y + fan * (card_count - 1) as f32;
             let top_edge = center.y + layout.card_size.y / 2.0;
             let bottom_edge = bottom_card_center_y - layout.card_size.y / 2.0;
@@ -1204,12 +1220,17 @@ fn pile_drop_rect(pile: &PileType, layout: &Layout, game: &GameState) -> (Vec2,
 }
 
 // ---------------------------------------------------------------------------
-// Task #27 — Double-click to auto-move
+// Task #27 — Double-click / double-tap to auto-move
 // ---------------------------------------------------------------------------
 
 /// Maximum seconds between two clicks to count as a double-click.
 const DOUBLE_CLICK_WINDOW: f32 = 0.35;
 
+/// Duration of the lime flash applied to moved cards when a tap
+/// auto-move succeeds. Short enough not to linger, long enough to register
+/// during the card animation (~0.3 s).
+const DOUBLE_TAP_FLASH_SECS: f32 = 0.35;
+
 /// Find the best legal destination for `card` — Foundation first, then Tableau.
 ///
 /// Returns `None` if no legal move exists from the card's current location.
@@ -1363,6 +1384,116 @@ fn handle_double_click(
     }
 }
 
+// ---------------------------------------------------------------------------
+// Tap-to-move (touch equivalent of mouse auto-move)
+// ---------------------------------------------------------------------------
+
+/// Fires `MoveRequestEvent` when the player taps a face-up card without
+/// dragging — the touch equivalent of the mouse auto-move flow.
+///
+/// Must run **before** `touch_end_drag` in the system chain. At
+/// `TouchPhase::Ended` the drag state still holds `active_touch_id`,
+/// `cards`, and `origin_pile`; once `touch_end_drag` fires those fields
+/// are cleared and the tap/drag distinction is permanently lost.
+///
+/// Move priority:
+/// 1. Single top card to its best foundation (or tableau).
+/// 2. Whole face-up run to best tableau column when no single-card move exists.
+/// 3. `MoveRejectedEvent` for audio + shake feedback when no legal move found.
+#[allow(clippy::too_many_arguments)]
+fn handle_double_tap(
+    mut touch_events: MessageReader<TouchInput>,
+    paused: Option<Res<PausedResource>>,
+    radial: Option<Res<RightClickRadialState>>,
+    drag: Res<DragState>,
+    game: Res<GameStateResource>,
+    mut moves: MessageWriter<MoveRequestEvent>,
+    mut rejected: MessageWriter<MoveRejectedEvent>,
+    mut commands: Commands,
+    mut card_sprites: Query<(Entity, &CardEntity, &mut Sprite)>,
+) {
+    if paused.is_some_and(|p| p.0) {
+        return;
+    }
+    // Long-press opened the radial — let radial_handle_release_or_cancel own
+    // the finger-lift event.
+    if radial.is_some_and(|r| r.is_active()) {
+        return;
+    }
+
+    let Some(active_id) = drag.active_touch_id else { return };
+    if drag.committed {
+        return;
+    }
+
+    for event in touch_events.read() {
+        if event.id != active_id || event.phase != TouchPhase::Ended {
+            continue;
+        }
+
+        // Uncommitted touch ended = pure tap.
+        let Some(&top_card_id) = drag.cards.last() else { return };
+        let Some(ref pile) = drag.origin_pile else { return };
+        let Some(pile_cards) = game.0.piles.get(pile) else { return };
+
+        let Some(top_card) = pile_cards.cards.iter().find(|c| c.id == top_card_id) else {
+            return;
+        };
+        if !top_card.face_up {
+            return;
+        }
+
+        // Priority 1: move single top card.
+        if let Some(dest) = best_destination(top_card, &game.0) {
+            for (entity, ce, mut sprite) in card_sprites.iter_mut() {
+                if ce.card_id == top_card_id {
+                    sprite.color = STATE_SUCCESS;
+                    commands.entity(entity).insert(HintHighlight { remaining: DOUBLE_TAP_FLASH_SECS });
+                    break;
+                }
+            }
+            moves.write(MoveRequestEvent {
+                from: pile.clone(),
+                to: dest,
+                count: 1,
+            });
+            return;
+        }
+
+        // Priority 2: move whole face-up stack to best tableau column.
+        if drag.cards.len() > 1 {
+            let stack_index = pile_cards.cards.len() - drag.cards.len();
+            if let Some(bottom_card) = pile_cards.cards.get(stack_index)
+                && let Some((dest, count)) = best_tableau_destination_for_stack(
+                    bottom_card,
+                    pile,
+                    &game.0,
+                    drag.cards.len(),
+                )
+            {
+                for (entity, ce, mut sprite) in card_sprites.iter_mut() {
+                    if drag.cards.contains(&ce.card_id) {
+                        sprite.color = STATE_SUCCESS;
+                        commands.entity(entity).insert(HintHighlight { remaining: DOUBLE_TAP_FLASH_SECS });
+                    }
+                }
+                moves.write(MoveRequestEvent {
+                    from: pile.clone(),
+                    to: dest,
+                    count,
+                });
+                return;
+            }
+        }
+
+        rejected.write(MoveRejectedEvent {
+            from: pile.clone(),
+            to: pile.clone(),
+            count: drag.cards.len(),
+        });
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Task #28 — Hint system helpers
 // ---------------------------------------------------------------------------
@@ -1501,7 +1632,7 @@ mod tests {
     #[test]
     fn find_draggable_picks_top_of_tableau() {
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
 
         // In tableau 6, the visually topmost card is the last (face-up) one.
         // Its position: base.y + fan * 6.
@@ -1515,7 +1646,7 @@ mod tests {
     #[test]
     fn find_draggable_skips_face_down_cards() {
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
 
         // Tableau 6 has 7 cards: 6 face-down (indices 0..5) + 1 face-up at
         // the bottom (index 6). Click at the topmost face-down card's
@@ -1536,7 +1667,7 @@ mod tests {
         // face-up bottom card, clicking the visible card face missed the
         // hit-test box and only the bottom strip of the card responded.
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
 
         // Tableau 6 starts with 6 face-down + 1 face-up. The face-up card
         // sits at base.y - 6 * TABLEAU_FACEDOWN_FAN_FRAC * card_h, NOT at
@@ -1575,7 +1706,7 @@ mod tests {
             face_up: true,
         });
 
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         // The Queen's geometric center (index 1) is inside the Jack's bounding box
         // (Jack fans 0.5h below base; its box spans [base-h, base]).  To hit the
         // Queen we click in her visible strip: the 0.25h band above the Jack's top
@@ -1607,7 +1738,7 @@ mod tests {
             face_up: true,
         });
 
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         // Both cards in waste sit at the same (x, y). Clicking should pick
         // the visually top card (id 201), with count = 1.
         let pos = card_position(&game, &layout, &PileType::Waste, 0);
@@ -1620,7 +1751,7 @@ mod tests {
     #[test]
     fn find_drop_target_hits_empty_tableau_pile_marker() {
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         // Move all cards out of tableau 0 so its marker is the only drop area.
         let mut game = game;
         game.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.clear();
@@ -1632,7 +1763,7 @@ mod tests {
     #[test]
     fn find_drop_target_returns_none_for_origin() {
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let pos = layout.pile_positions[&PileType::Tableau(3)];
         let target = find_drop_target(pos, &game, &layout, &PileType::Tableau(3));
         assert_eq!(target, None);
@@ -1641,7 +1772,7 @@ mod tests {
     #[test]
     fn pile_drop_rect_extends_for_tableau_with_cards() {
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         // Tableau 6 has 7 cards.
         let (_, size) = pile_drop_rect(&PileType::Tableau(6), &layout, &game);
         // Expected: card_height + 6 * fan. fan = 0.25 * card_height, so
@@ -1666,7 +1797,7 @@ mod tests {
         waste.cards.push(Card { id: 201, suit: Suit::Hearts, rank: Rank::Three, face_up: true });
         waste.cards.push(Card { id: 202, suit: Suit::Clubs, rank: Rank::Four, face_up: true });
 
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let waste_base = layout.pile_positions[&PileType::Waste];
         // Top card (slot=2) is at base.x + 2 * 0.28 * card_width.
         let top_card_x = waste_base.x + 2.0 * 0.28 * layout.card_size.x;
@@ -1682,7 +1813,7 @@ mod tests {
     #[test]
     fn find_draggable_returns_none_for_click_on_empty_pile() {
         let mut game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         // Clear tableau 0 so it's an empty slot.
         game.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.clear();
         let pos = layout.pile_positions[&PileType::Tableau(0)];
@@ -1693,7 +1824,7 @@ mod tests {
     #[test]
     fn pile_drop_rect_is_card_sized_for_non_tableau() {
         let game = GameState::new(42, DrawMode::DrawOne);
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         for pile in [
             PileType::Waste,
             PileType::Foundation(2),
@@ -2194,7 +2325,7 @@ mod tests {
         app.init_resource::<crate::pending_hint::PendingHintTask>();
         app.init_resource::<ButtonInput<KeyCode>>();
         app.insert_resource(crate::layout::LayoutResource(
-            crate::layout::compute_layout(Vec2::new(1280.0, 800.0)),
+            crate::layout::compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0),
         ));
         app.insert_resource(GameStateResource(GameState::new(42, DrawMode::DrawOne)));
         app.add_systems(Update, handle_keyboard_hint);
@@ -2215,5 +2346,6 @@ mod tests {
             "pressing H must spawn an async hint task",
         );
     }
+
 }
 

solitaire_engine/src/layout.rs

@@ -21,9 +21,25 @@ pub enum LayoutSystem {
     UpdateOnResize,
 }
 
-/// Minimum supported window dimensions. Layout is still computed below this
+/// Minimum window dimensions used as a layout floor.
-/// size but cards will be small.
+///
-pub const MIN_WINDOW: Vec2 = Vec2::new(800.0, 600.0);
+/// `compute_layout` runs `window.max(MIN_WINDOW)` so a window smaller than this
+/// on either axis is laid out as if it were at least this size. The floor
+/// exists to guard against degenerate / divide-by-zero layouts on very small
+/// surfaces (Bevy can briefly report 0-size windows during startup or after
+/// minimisation on some compositors); it is not a "minimum supported playable
+/// size" — desktop builds enforce that via `WindowResizeConstraints` set in
+/// `solitaire_app::lib`.
+///
+/// The previous floor of 800×600 was set with desktop in mind and produced
+/// the wrong behaviour on Android: a 360 dp phone got laid out as if it were
+/// 800-wide, pushing the leftmost foundation past `-180` and the rightmost
+/// tableau pile past `+180`, which clipped both at the visible viewport
+/// edges (visible in the v0.22.3 hardware screenshot). 320×400 is below the
+/// smallest reasonable phone (≈ 360×640) so every real device flows through
+/// without clamping, while still being large enough that the layout math
+/// produces non-degenerate card sizes.
+pub const MIN_WINDOW: Vec2 = Vec2::new(320.0, 400.0);
 
 /// Aspect ratio (height / width) of a standard playing card.
 ///
@@ -36,11 +52,22 @@ const CARD_ASPECT: f32 = 1.4523;
 /// the tableau row.
 const VERTICAL_GAP_FRAC: f32 = 0.2;
 
-/// Fraction of card height contributed by each additional face-up tableau card
+/// Minimum fraction of card height used as vertical offset between face-up
-/// when fanned. Mirrors `card_plugin::TABLEAU_FAN_FRAC` so layout sizing can
+/// tableau cards. Used for the height-based sizing candidate (worst-case
-/// solve for a worst-case column without depending on `card_plugin`.
+/// column must fit at this fraction). On desktop (height-limited) windows the
+/// adaptive computation returns this value exactly; on portrait phones it
+/// expands to fill available vertical space.
 const TABLEAU_FAN_FRAC: f32 = 0.25;
 
+/// Minimum fraction for face-down tableau cards. Scales proportionally with
+/// the adaptive face-up fraction so hit-testing and rendering stay in sync.
+///
+/// Raised from 0.12 to 0.20 so face-down stacks on portrait phones show
+/// enough of each card back to read as a meaningful stack rather than a
+/// thin sliver. The ratio to TABLEAU_FAN_FRAC (0.80) is preserved by
+/// the adaptive scaling in `compute_layout`.
+const TABLEAU_FACEDOWN_FAN_FRAC: f32 = 0.20;
+
 /// Largest possible face-up tableau column in Klondike: a King down to an Ace
 /// after every face-down card has flipped on column 7. Layout sizing must keep
 /// this column inside the visible window.
@@ -50,10 +77,15 @@ const MAX_TABLEAU_CARDS: f32 = 13.0;
 /// (action buttons, Score / Moves / Timer readouts). The card grid starts
 /// below this band so the HUD doesn't bleed into the play surface.
 ///
-/// 64 px comfortably fits the action button bar (~32 px tall) plus the
+/// Desktop: 64 px fits the single-row action bar plus the Score/Moves line.
-/// Score/Moves text line plus padding, with a few pixels of breathing room.
+/// Android: 128 px accommodates the two-row button wrap on narrow phones
-/// The matching translucent background is painted by `hud_plugin::spawn_hud_band`.
+/// (7 buttons × ~52 dp each, with a 65% max-width constraint, wraps to two
+/// ~48 dp rows plus row-gap). Without this larger reserve the bottom row of
+/// buttons overlaps the top card row.
+#[cfg(not(target_os = "android"))]
 pub const HUD_BAND_HEIGHT: f32 = 64.0;
+#[cfg(target_os = "android")]
+pub const HUD_BAND_HEIGHT: f32 = 128.0;
 
 /// Table background colour (dark green felt).
 pub const TABLE_COLOUR: [f32; 3] = [0.059, 0.322, 0.196];
@@ -72,9 +104,33 @@ pub struct Layout {
     /// Every `PileType` (Stock, Waste, four Foundations, seven Tableaux) has an
     /// entry. The map always contains exactly 13 entries after `compute_layout`.
     pub pile_positions: HashMap<PileType, Vec2>,
+    /// Per-step vertical offset fraction for face-up tableau cards, as a
+    /// fraction of `card_size.y`. On height-limited (desktop) windows this
+    /// equals `TABLEAU_FAN_FRAC` (0.25); on width-limited (portrait phone)
+    /// windows it expands to fill the available vertical space so the tableau
+    /// stretches to the bottom of the screen. Card rendering (`card_plugin`)
+    /// and hit testing (`input_plugin`) both read from this field so they
+    /// stay in sync.
+    pub tableau_fan_frac: f32,
+    /// Per-step vertical offset fraction for face-down tableau cards, as a
+    /// fraction of `card_size.y`. Scales proportionally with `tableau_fan_frac`
+    /// (ratio preserved from `TABLEAU_FACEDOWN_FAN_FRAC / TABLEAU_FAN_FRAC`).
+    pub tableau_facedown_fan_frac: f32,
+    /// Vertical pixel budget available for tableau fan steps — the distance
+    /// from the top edge of the first tableau card to the bottom margin, in
+    /// logical pixels. Used by `card_plugin::update_tableau_fan_frac` to
+    /// recompute `tableau_fan_frac` dynamically based on the actual max
+    /// face-up column depth after each game state change.
+    pub available_tableau_height: f32,
 }
 
-/// Compute the board layout from a window size.
+/// Compute the board layout from a window size and safe-area insets.
+///
+/// `safe_area_top` and `safe_area_bottom` are the **logical-pixel** heights of
+/// the OS-reserved regions at the top and bottom of the screen (status bar and
+/// gesture / navigation bar on Android). Pass `0.0` on desktop or when the
+/// inset is unknown. Android's `WindowInsets` API returns **physical** pixels;
+/// callers must divide by `window.scale_factor()` before passing values here.
 ///
 /// # Geometry
 /// - `card_width` is the smaller of:
@@ -90,7 +146,7 @@ pub struct Layout {
 /// - Top row (stock, waste, 4 foundations) aligns with tableau columns
 ///   0, 1, 3, 4, 5, 6 — column 2 is intentionally empty to separate the
 ///   waste/stock cluster from the foundations.
-pub fn compute_layout(window: Vec2) -> Layout {
+pub fn compute_layout(window: Vec2, safe_area_top: f32, safe_area_bottom: f32) -> Layout {
     let window = window.max(MIN_WINDOW);
 
     // Width-based candidate (existing behaviour): 7 cards + 8 h_gaps = 9*card_width.
@@ -113,7 +169,7 @@ pub fn compute_layout(window: Vec2) -> Layout {
     //   (window.y - HUD_BAND_HEIGHT) = w * (0.5 + (1 + fan_factor + VERTICAL_GAP_FRAC) * CARD_ASPECT)
     let fan_factor = 1.0 + (MAX_TABLEAU_CARDS - 1.0) * TABLEAU_FAN_FRAC;
     let height_denom = 0.5 + (1.0 + fan_factor + VERTICAL_GAP_FRAC) * CARD_ASPECT;
-    let card_width_height_based = (window.y - HUD_BAND_HEIGHT).max(0.0) / height_denom;
+    let card_width_height_based = (window.y - safe_area_top - safe_area_bottom - HUD_BAND_HEIGHT).max(0.0) / height_denom;
 
     let card_width = card_width_width_based.min(card_width_height_based);
     let card_height = card_width * CARD_ASPECT;
@@ -133,7 +189,7 @@ pub fn compute_layout(window: Vec2) -> Layout {
     };
 
     let vertical_gap = card_height * VERTICAL_GAP_FRAC;
-    let top_y = window.y / 2.0 - HUD_BAND_HEIGHT - h_gap - card_height / 2.0;
+    let top_y = window.y / 2.0 - safe_area_top - HUD_BAND_HEIGHT - h_gap - card_height / 2.0;
     let tableau_y = top_y - card_height - vertical_gap;
 
     let mut pile_positions: HashMap<PileType, Vec2> = HashMap::with_capacity(13);
@@ -153,9 +209,36 @@ pub fn compute_layout(window: Vec2) -> Layout {
         pile_positions.insert(PileType::Tableau(i), Vec2::new(col_x(i), tableau_y));
     }
 
+    // Adaptive tableau fan fraction. On height-limited (desktop) windows the
+    // height-based sizing already ensures a worst-case 13-card column fits at
+    // TABLEAU_FAN_FRAC (0.25), so the formula returns ≈0.25 and the clamp
+    // keeps it there — no change from prior behaviour. On width-limited
+    // (portrait phone) windows card_size is small and lots of vertical space
+    // is unused; we solve for the fraction that exactly fills the available
+    // space to the bottom margin.
+    //
+    // avail = distance from the top of the first tableau card to the bottom
+    //         margin — i.e. the space available for 12 fan steps.
+    let avail = (tableau_y - (-window.y / 2.0 + safe_area_bottom + h_gap) - card_height / 2.0).max(0.0);
+    let ideal_fan_frac = if card_height > 0.0 {
+        avail / ((MAX_TABLEAU_CARDS - 1.0) * card_height)
+    } else {
+        TABLEAU_FAN_FRAC
+    };
+    // Never go below the desktop minimum — avoids shrinking the fan on
+    // degenerate near-square windows where the formula might undershoot.
+    let tableau_fan_frac = ideal_fan_frac.max(TABLEAU_FAN_FRAC);
+    // Scale the face-down fraction proportionally so rendering and hit-testing
+    // stay in sync (TABLEAU_FACEDOWN_FAN_FRAC / TABLEAU_FAN_FRAC = 0.48 ratio).
+    let facedown_scale = TABLEAU_FACEDOWN_FAN_FRAC / TABLEAU_FAN_FRAC;
+    let tableau_facedown_fan_frac = tableau_fan_frac * facedown_scale;
+
     Layout {
         card_size,
         pile_positions,
+        tableau_fan_frac,
+        tableau_facedown_fan_frac,
+        available_tableau_height: avail,
     }
 }
 
@@ -187,15 +270,15 @@ mod tests {
 
     #[test]
     fn layout_has_all_thirteen_piles() {
-        assert_all_piles_present(&compute_layout(Vec2::new(1280.0, 800.0)));
+        assert_all_piles_present(&compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0));
-        assert_all_piles_present(&compute_layout(Vec2::new(800.0, 600.0)));
+        assert_all_piles_present(&compute_layout(Vec2::new(800.0, 600.0), 0.0, 0.0));
-        assert_all_piles_present(&compute_layout(Vec2::new(1920.0, 1080.0)));
+        assert_all_piles_present(&compute_layout(Vec2::new(1920.0, 1080.0), 0.0, 0.0));
     }
 
     #[test]
     fn card_size_scales_with_window_width() {
-        let small = compute_layout(Vec2::new(800.0, 600.0));
+        let small = compute_layout(Vec2::new(800.0, 600.0), 0.0, 0.0);
-        let large = compute_layout(Vec2::new(1920.0, 1080.0));
+        let large = compute_layout(Vec2::new(1920.0, 1080.0), 0.0, 0.0);
         assert!(large.card_size.x > small.card_size.x);
         assert!(
             (large.card_size.y / large.card_size.x - CARD_ASPECT).abs() < 1e-5,
@@ -205,14 +288,42 @@ mod tests {
 
     #[test]
     fn layout_below_minimum_clamps_to_minimum() {
-        let below = compute_layout(Vec2::new(400.0, 300.0));
+        // 200×200 sits below the floor on both axes, so the clamp pulls each
-        let at_min = compute_layout(MIN_WINDOW);
+        // axis up to MIN_WINDOW and the layout matches compute_layout(MIN_WINDOW, 0.0, 0.0).
+        let below = compute_layout(Vec2::new(200.0, 200.0), 0.0, 0.0);
+        let at_min = compute_layout(MIN_WINDOW, 0.0, 0.0);
         assert_eq!(below.card_size, at_min.card_size);
     }
 
+    /// Regression for the v0.22.3 Android viewport-overflow bug. A typical
+    /// portrait-phone viewport (360 dp × 800 dp) must produce a layout
+    /// where every pile fits horizontally — i.e. card_width is derived
+    /// from the actual window, not a clamped-up desktop floor.
+    #[test]
+    fn phone_portrait_layout_fits_horizontally() {
+        let window = Vec2::new(360.0, 800.0);
+        let layout = compute_layout(window, 0.0, 0.0);
+        let half_w = window.x / 2.0;
+        let half_card = layout.card_size.x / 2.0;
+        for (pile, pos) in &layout.pile_positions {
+            assert!(
+                pos.x - half_card >= -half_w - 1e-3,
+                "{:?} overflows left at portrait phone window {:?}",
+                pile,
+                window
+            );
+            assert!(
+                pos.x + half_card <= half_w + 1e-3,
+                "{:?} overflows right at portrait phone window {:?}",
+                pile,
+                window
+            );
+        }
+    }
+
     #[test]
     fn tableau_columns_are_sorted_left_to_right() {
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         for i in 0..6 {
             let lhs = layout.pile_positions[&PileType::Tableau(i)].x;
             let rhs = layout.pile_positions[&PileType::Tableau(i + 1)].x;
@@ -222,7 +333,7 @@ mod tests {
 
     #[test]
     fn top_row_is_above_tableau_row() {
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let stock_y = layout.pile_positions[&PileType::Stock].y;
         let tableau_y = layout.pile_positions[&PileType::Tableau(0)].y;
         assert!(stock_y > tableau_y);
@@ -235,7 +346,7 @@ mod tests {
     #[test]
     fn top_row_clears_hud_band() {
         let window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(window);
+        let layout = compute_layout(window, 0.0, 0.0);
         let stock_y = layout.pile_positions[&PileType::Stock].y;
         let card_top = stock_y + layout.card_size.y / 2.0;
         let band_bottom = window.y / 2.0 - HUD_BAND_HEIGHT;
@@ -247,7 +358,7 @@ mod tests {
 
     #[test]
     fn stock_aligns_with_tableau_col_0_and_waste_with_col_1() {
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         let stock_x = layout.pile_positions[&PileType::Stock].x;
         let waste_x = layout.pile_positions[&PileType::Waste].x;
         let t0_x = layout.pile_positions[&PileType::Tableau(0)].x;
@@ -258,7 +369,7 @@ mod tests {
 
     #[test]
     fn foundations_align_with_tableau_cols_3_to_6() {
-        let layout = compute_layout(Vec2::new(1280.0, 800.0));
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
         for slot in 0..4_u8 {
             let f_x = layout.pile_positions[&PileType::Foundation(slot)].x;
             let t_x = layout.pile_positions[&PileType::Tableau(3 + slot as usize)].x;
@@ -277,7 +388,7 @@ mod tests {
         // keep a worst-case 13-card column inside the window. (Most desktop
         // monitors fall into this regime — e.g. 1280x800, 1920x1080.)
         let window = Vec2::new(2560.0, 1080.0);
-        let layout = compute_layout(window);
+        let layout = compute_layout(window, 0.0, 0.0);
         let width_based = window.x / 9.0;
         assert!(
             layout.card_size.x < width_based,
@@ -293,7 +404,7 @@ mod tests {
         // the bottleneck and card_width matches the legacy window.x / 9
         // derivation exactly.
         let window = Vec2::new(900.0, 1600.0);
-        let layout = compute_layout(window);
+        let layout = compute_layout(window, 0.0, 0.0);
         let width_based = window.x / 9.0;
         assert!(
             (layout.card_size.x - width_based).abs() < 1e-3,
@@ -307,7 +418,7 @@ mod tests {
     fn worst_case_tableau_fits_vertically_on_default_resolution() {
         // Default app resolution (see solitaire_app/src/main.rs).
         let window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(window);
+        let layout = compute_layout(window, 0.0, 0.0);
         let tableau_y = layout.pile_positions[&PileType::Tableau(6)].y;
         let card_h = layout.card_size.y;
         // Bottom edge of the 13th fanned face-up card.
@@ -326,7 +437,7 @@ mod tests {
     fn worst_case_tableau_fits_vertically_on_full_hd() {
         // The bug originally reproduced at 1920x1080. Lock in a regression test.
         let window = Vec2::new(1920.0, 1080.0);
-        let layout = compute_layout(window);
+        let layout = compute_layout(window, 0.0, 0.0);
         let tableau_y = layout.pile_positions[&PileType::Tableau(6)].y;
         let card_h = layout.card_size.y;
         let bottom_edge = tableau_y - 12.0 * card_h * TABLEAU_FAN_FRAC - card_h / 2.0;
@@ -338,6 +449,50 @@ mod tests {
         );
     }
 
+    /// Portrait phone (width-limited) should expand the fan fraction beyond
+    /// the desktop minimum so the tableau fills the available vertical space.
+    #[test]
+    fn portrait_phone_expands_tableau_fan_frac() {
+        let desktop = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
+        let phone = compute_layout(Vec2::new(360.0, 800.0), 0.0, 0.0);
+        assert!(
+            phone.tableau_fan_frac > desktop.tableau_fan_frac,
+            "portrait phone fan_frac ({:.3}) should exceed desktop ({:.3})",
+            phone.tableau_fan_frac,
+            desktop.tableau_fan_frac,
+        );
+    }
+
+    /// The expanded fan on a portrait phone must not overflow the visible
+    /// window — the worst-case 13-card column must stay above the bottom margin.
+    #[test]
+    fn expanded_fan_fits_phone_viewport() {
+        let window = Vec2::new(360.0, 800.0);
+        let layout = compute_layout(window, 0.0, 0.0);
+        let tableau_y = layout.pile_positions[&PileType::Tableau(0)].y;
+        let card_h = layout.card_size.y;
+        let h_gap = layout.card_size.x / 4.0;
+        // Bottom of the 13th (worst-case) fanned face-up card.
+        let bottom = tableau_y - 12.0 * layout.tableau_fan_frac * card_h - card_h / 2.0;
+        let margin = -window.y / 2.0 + h_gap;
+        assert!(
+            bottom >= margin - 1e-3,
+            "worst-case fan overflows phone viewport: bottom={bottom:.1} < margin={margin:.1}",
+        );
+    }
+
+    /// Desktop (height-limited) must keep the minimum fan fraction so the
+    /// existing worst-case-fits-vertically invariant is preserved.
+    #[test]
+    fn desktop_tableau_fan_frac_is_minimum() {
+        let layout = compute_layout(Vec2::new(1280.0, 800.0), 0.0, 0.0);
+        assert!(
+            (layout.tableau_fan_frac - TABLEAU_FAN_FRAC).abs() < 1e-3,
+            "desktop fan_frac should stay at minimum {TABLEAU_FAN_FRAC}, got {:.4}",
+            layout.tableau_fan_frac,
+        );
+    }
+
     #[test]
     fn all_piles_fit_inside_window_horizontally() {
         for window in [
@@ -345,7 +500,7 @@ mod tests {
             Vec2::new(1280.0, 800.0),
             Vec2::new(1920.0, 1080.0),
         ] {
-            let layout = compute_layout(window);
+            let layout = compute_layout(window, 0.0, 0.0);
             let half_w = window.x / 2.0;
             let half_card = layout.card_size.x / 2.0;
             for (pile, pos) in &layout.pile_positions {
@@ -364,4 +519,85 @@ mod tests {
             }
         }
     }
+
+    /// A non-zero `safe_area_top` must shift both the top row and the tableau
+    /// downward by the same amount — so the first card row stays below the
+    /// status-bar band and the tableau tracks it proportionally.
+    #[test]
+    fn safe_area_top_shifts_top_row_downward() {
+        let window = Vec2::new(360.0, 800.0);
+        let without = compute_layout(window, 0.0, 0.0);
+        let with_inset = compute_layout(window, 32.0, 0.0);
+        let stock_no_inset = without.pile_positions[&PileType::Stock].y;
+        let stock_with_inset = with_inset.pile_positions[&PileType::Stock].y;
+        assert!(
+            stock_with_inset < stock_no_inset,
+            "safe_area_top=32 must shift stock pile down (y decreased): {} → {}",
+            stock_no_inset,
+            stock_with_inset,
+        );
+        assert!(
+            (stock_no_inset - stock_with_inset - 32.0).abs() < 1e-3,
+            "stock pile must shift by exactly safe_area_top (32 dp): delta was {:.3}",
+            stock_no_inset - stock_with_inset,
+        );
+    }
+
+    /// With a safe-area inset the card grid must still fit horizontally —
+    /// safe_area_top only affects the vertical budget.
+    #[test]
+    fn safe_area_top_does_not_affect_horizontal_layout() {
+        let window = Vec2::new(360.0, 800.0);
+        let without = compute_layout(window, 0.0, 0.0);
+        let with_inset = compute_layout(window, 32.0, 0.0);
+        for pile in [
+            PileType::Stock,
+            PileType::Waste,
+            PileType::Tableau(0),
+            PileType::Tableau(6),
+        ] {
+            assert!(
+                (without.pile_positions[&pile].x - with_inset.pile_positions[&pile].x).abs() < 1e-3,
+                "{pile:?} x-position must not change with safe_area_top",
+            );
+        }
+    }
+
+    /// A bottom safe-area inset must shrink the tableau fan so the worst-case
+    /// column stays above the gesture bar.
+    #[test]
+    fn safe_area_bottom_reduces_tableau_fan() {
+        let window = Vec2::new(360.0, 800.0);
+        let without = compute_layout(window, 0.0, 0.0);
+        let with_inset = compute_layout(window, 0.0, 48.0);
+        assert!(
+            with_inset.tableau_fan_frac <= without.tableau_fan_frac,
+            "safe_area_bottom=48 must not increase tableau_fan_frac: {:.4} → {:.4}",
+            without.tableau_fan_frac,
+            with_inset.tableau_fan_frac,
+        );
+        let card_h = with_inset.card_size.y;
+        let tableau_y = with_inset.pile_positions[&PileType::Tableau(6)].y;
+        let bottom_edge = tableau_y - 12.0 * card_h * with_inset.tableau_fan_frac - card_h / 2.0;
+        let h_gap = with_inset.card_size.x / 4.0;
+        let margin = -window.y / 2.0 + 48.0 + h_gap;
+        assert!(
+            bottom_edge >= margin - 1e-3,
+            "worst-case tableau bottom {bottom_edge:.2} overflows gesture-bar margin {margin:.2}",
+        );
+    }
+
+    /// safe_area_bottom must not affect horizontal positions.
+    #[test]
+    fn safe_area_bottom_does_not_affect_horizontal_layout() {
+        let window = Vec2::new(360.0, 800.0);
+        let without = compute_layout(window, 0.0, 0.0);
+        let with_inset = compute_layout(window, 0.0, 48.0);
+        for pile in [PileType::Stock, PileType::Tableau(0), PileType::Tableau(6)] {
+            assert!(
+                (without.pile_positions[&pile].x - with_inset.pile_positions[&pile].x).abs() < 1e-3,
+                "{pile:?} x-position must not change with safe_area_bottom",
+            );
+        }
+    }
 }

solitaire_engine/src/lib.rs

@@ -1,5 +1,7 @@
 //! Bevy integration layer for Solitaire Quest.
 
+#[cfg(target_os = "android")]
+pub mod android_clipboard;
 pub mod assets;
 pub mod card_animation;
 pub mod achievement_plugin;
@@ -12,6 +14,7 @@ pub mod feedback_anim_plugin;
 pub mod challenge_plugin;
 pub mod cursor_plugin;
 pub mod daily_challenge_plugin;
+pub mod difficulty_plugin;
 pub mod diagnostics_hud;
 pub mod events;
 pub mod game_plugin;
@@ -24,6 +27,7 @@ pub mod layout;
 pub mod onboarding_plugin;
 pub mod pause_plugin;
 pub mod pending_hint;
+pub mod play_by_seed_plugin;
 pub mod profile_plugin;
 pub mod radial_menu;
 pub mod replay_overlay;
@@ -31,10 +35,12 @@ pub mod replay_playback;
 pub mod settings_plugin;
 pub mod progress_plugin;
 pub mod resources;
+pub mod safe_area;
 pub mod selection_plugin;
 pub mod splash_plugin;
 pub mod stats_plugin;
 pub mod sync_plugin;
+pub mod sync_setup_plugin;
 pub mod table_plugin;
 pub mod theme;
 pub mod time_attack_plugin;
@@ -92,11 +98,14 @@ pub use events::{
     ForfeitEvent, ForfeitRequestEvent, FoundationCompletedEvent, GameWonEvent, HelpRequestEvent,
     HintVisualEvent, InfoToastEvent, ManualSyncRequestEvent, MoveRejectedEvent, MoveRequestEvent,
     NewGameRequestEvent, PauseRequestEvent, StartChallengeRequestEvent,
-    StartDailyChallengeRequestEvent, StartTimeAttackRequestEvent, StartZenRequestEvent,
+    StartDailyChallengeRequestEvent, StartDifficultyRequestEvent, StartPlayBySeedRequestEvent,
-    StateChangedEvent, SyncCompleteEvent, ToggleAchievementsRequestEvent,
+    StartTimeAttackRequestEvent, StartZenRequestEvent, StateChangedEvent, SyncCompleteEvent,
-    ToggleLeaderboardRequestEvent, ToggleProfileRequestEvent, ToggleSettingsRequestEvent,
+    ToggleAchievementsRequestEvent, ToggleLeaderboardRequestEvent, ToggleProfileRequestEvent,
-    ToggleStatsRequestEvent, UndoRequestEvent, WinStreakMilestoneEvent, XpAwardedEvent,
+    ToggleSettingsRequestEvent, ToggleStatsRequestEvent, UndoRequestEvent,
+    WinStreakMilestoneEvent, XpAwardedEvent,
 };
+pub use difficulty_plugin::{DifficultyIndexResource, DifficultyPlugin};
+pub use play_by_seed_plugin::{PlayBySeedPlugin, PlayBySeedScreen};
 pub use game_plugin::{
     ConfirmNewGameScreen, GameMutation, GameOverScreen, GamePlugin, GameStatePath, RecordingReplay,
     ReplayPath,
@@ -131,6 +140,7 @@ pub use settings_plugin::{
 };
 pub use layout::{compute_layout, Layout, LayoutResource};
 pub use resources::{DragState, GameStateResource, HintCycleIndex, SettingsScrollPos, SyncStatus, SyncStatusResource};
+pub use safe_area::{SafeAreaAnchoredTop, SafeAreaInsets, SafeAreaInsetsPlugin};
 pub use selection_plugin::{
     KeyboardDragState, SelectionHighlight, SelectionPlugin, SelectionState,
 };
@@ -141,6 +151,7 @@ pub use stats_plugin::{
     StatsScreen, StatsUpdate, WatchReplayButton,
 };
 pub use sync_plugin::{SyncPlugin, SyncProviderResource};
+pub use sync_setup_plugin::SyncSetupPlugin;
 pub use ui_focus::{Disabled, FocusGroup, Focusable, FocusedButton, UiFocusPlugin};
 pub use ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_body_text, spawn_modal_button,

solitaire_engine/src/onboarding_plugin.rs

@@ -32,8 +32,8 @@ use crate::ui_modal::{
     spawn_modal_header, ButtonVariant,
 };
 use crate::ui_theme::{
-    BORDER_SUBTLE, RADIUS_SM, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_CAPTION, TYPE_BODY, VAL_SPACE_1,
+    BORDER_SUBTLE, HighContrastBorder, RADIUS_SM, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY,
-    VAL_SPACE_2, VAL_SPACE_3, Z_ONBOARDING,
+    TYPE_CAPTION, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, Z_ONBOARDING,
 };
 
 // ---------------------------------------------------------------------------
@@ -41,7 +41,13 @@ use crate::ui_theme::{
 // ---------------------------------------------------------------------------
 
 /// Total number of onboarding slides (0-based index goes 0..SLIDE_COUNT-1).
+///
+/// Android omits the keyboard-shortcuts slide (index 2) because there is no
+/// physical keyboard on a touchscreen device, dropping the count to 2.
+#[cfg(not(target_os = "android"))]
 const SLIDE_COUNT: u8 = 3;
+#[cfg(target_os = "android")]
+const SLIDE_COUNT: u8 = 2;
 
 // ---------------------------------------------------------------------------
 // Components (private — never re-exported)
@@ -276,6 +282,8 @@ fn spawn_slide(commands: &mut Commands, index: u8, font_res: Option<&FontResourc
     match index {
         0 => spawn_slide_welcome(commands, font_res),
         1 => spawn_slide_how_to_play(commands, font_res),
+        // Slide 2 (keyboard shortcuts) is desktop-only; Android has no keyboard.
+        #[cfg(not(target_os = "android"))]
         2 => spawn_slide_hotkeys(commands, font_res),
         _ => spawn_slide_welcome(commands, font_res),
     }
@@ -386,6 +394,7 @@ fn spawn_slide_hotkeys(commands: &mut Commands, font_res: Option<&FontResource>)
                         ..default()
                     },
                     BorderColor::all(BORDER_SUBTLE),
+                    HighContrastBorder::with_default(BORDER_SUBTLE),
                 ))
                 .with_children(|chip| {
                     chip.spawn((
@@ -663,8 +672,15 @@ mod tests {
     // -----------------------------------------------------------------------
 
     #[test]
+    #[cfg(not(target_os = "android"))]
     fn slide_count_constant_is_three() {
-        assert_eq!(SLIDE_COUNT, 3, "SLIDE_COUNT must be 3");
+        assert_eq!(SLIDE_COUNT, 3, "SLIDE_COUNT must be 3 on desktop");
+    }
+
+    #[test]
+    #[cfg(target_os = "android")]
+    fn slide_count_constant_is_two_on_android() {
+        assert_eq!(SLIDE_COUNT, 2, "SLIDE_COUNT must be 2 on Android (no keyboard slide)");
     }
 
     #[test]

solitaire_engine/src/pause_plugin.rs

@@ -30,6 +30,7 @@ use crate::events::{
 use crate::font_plugin::FontResource;
 use crate::game_plugin::{GameOverScreen, GameStatePath};
 use crate::progress_plugin::ProgressResource;
+use crate::replay_playback::ReplayPlaybackState;
 use crate::resources::{DragState, GameStateResource};
 use crate::selection_plugin::{SelectionKeySet, SelectionState};
 use crate::settings_plugin::{SettingsChangedEvent, SettingsResource, SettingsStoragePath};
@@ -154,6 +155,7 @@ fn toggle_pause(
     mut drag: Option<ResMut<DragState>>,
     mut changed: MessageWriter<StateChangedEvent>,
     selection: Option<Res<SelectionState>>,
+    replay_state: Option<Res<ReplayPlaybackState>>,
 ) {
     let PauseModalQueries {
         pause_screens: screens,
@@ -184,6 +186,15 @@ fn toggle_pause(
     if !other_modal_scrims.is_empty() {
         return;
     }
+    // If a replay is currently playing, let `replay_overlay::handle_stop_keyboard`
+    // own the Esc press — that handler stops the replay. Without this guard a
+    // single Esc both stops the replay AND opens the pause modal on top of the
+    // (now empty) board, leaving the player on a screen they didn't ask for.
+    // The HUD-button path is gated too; clicking Pause while watching a replay
+    // is almost always an accident.
+    if replay_state.is_some_and(|s| s.is_playing()) {
+        return;
+    }
     // If a card is currently selected, let SelectionPlugin handle this Escape
     // (it will clear the selection). Pause must not also open in the same frame.
     if selection.is_some_and(|s| s.selected_pile.is_some()) {

solitaire_engine/src/play_by_seed_plugin.rs

@@ -0,0 +1,663 @@
+//! Play-by-Seed dialog: lets the player type a decimal seed number and start
+//! a Classic game with that exact deal. A live solver-verification badge
+//! updates asynchronously after a short typing debounce so the player knows
+//! whether the deal is provably winnable before committing.
+//!
+//! # Flow
+//!
+//! 1. `HomePlugin` fires [`StartPlayBySeedRequestEvent`] when the "Play by
+//!    Seed" card is clicked (or `6` is pressed in the Mode Launcher).
+//! 2. `handle_open_dialog` reads the event and spawns the seed-input modal.
+//! 3. `handle_text_input` appends decimal digits / handles Backspace while
+//!    the modal is open, updating [`SeedInputBuffer`] each frame.
+//! 4. `tick_debounce_and_spawn_solver_task` waits for 12 frames (~200 ms at
+//!    60 Hz) of no input before spawning a [`try_solve`] task on
+//!    [`AsyncComputeTaskPool`]. Any fresh keypress drops the in-flight task
+//!    by resetting the resource.
+//! 5. `poll_solver_task` polls the in-flight task each frame and updates the
+//!    [`SolverVerdictBadge`] text node with the verdict.
+//! 6. `handle_confirm` fires [`NewGameRequestEvent`] with the parsed seed and
+//!    despawns the dialog on Play click or `Enter`.
+//! 7. `handle_cancel` despawns the dialog on Cancel click or `Escape`.
+
+use bevy::input::ButtonInput;
+use bevy::prelude::*;
+use bevy::tasks::{futures_lite::future, AsyncComputeTaskPool, Task};
+use solitaire_core::game_state::DrawMode;
+use solitaire_core::solver::{try_solve, SolverConfig, SolverResult};
+
+use crate::events::{NewGameRequestEvent, StartPlayBySeedRequestEvent};
+use crate::font_plugin::FontResource;
+use crate::game_plugin::GameMutation;
+use crate::settings_plugin::SettingsResource;
+use crate::ui_modal::{
+    spawn_modal, spawn_modal_actions, spawn_modal_body_text, spawn_modal_button, spawn_modal_header,
+    ButtonVariant, ScrimDismissible,
+};
+use crate::ui_theme::{
+    ACCENT_PRIMARY, BG_ELEVATED_PRESSED, BORDER_SUBTLE, HighContrastBorder, RADIUS_MD,
+    TEXT_DISABLED, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY_LG, VAL_SPACE_2, VAL_SPACE_3,
+    Z_MODAL_PANEL,
+};
+
+// ---------------------------------------------------------------------------
+// Components and resources
+// ---------------------------------------------------------------------------
+
+/// Marker on the seed-input modal scrim (the despawn root).
+#[derive(Component, Debug)]
+pub struct PlayBySeedScreen;
+
+/// Holds the decimal digit string the player is typing and a frame counter
+/// used to debounce solver task spawning.
+#[derive(Component, Debug, Default)]
+struct SeedInputBuffer {
+    /// Raw decimal digit string. Never longer than 20 chars (u64::MAX is 20
+    /// decimal digits). Empty means "no seed entered".
+    text: String,
+    /// Frames elapsed since the last keystroke. The solver task is spawned
+    /// once this crosses [`DEBOUNCE_FRAMES`] and the buffer is non-empty.
+    frames_since_change: u32,
+}
+
+/// Marker on the text node that renders the solver verdict caption.
+#[derive(Component, Debug)]
+struct SolverVerdictBadge;
+
+/// Marker on the Play (confirm) button so `handle_confirm` can find it.
+#[derive(Component, Debug)]
+struct PlayBySeedConfirmButton;
+
+/// Marker on the Cancel button.
+#[derive(Component, Debug)]
+struct PlayBySeedCancelButton;
+
+/// Marker on the input-field text node so `handle_text_input` can update
+/// it without a separate query for the buffer entity.
+#[derive(Component, Debug)]
+struct SeedInputDisplay;
+
+/// In-flight async solver verification task. At most one is live at a time —
+/// a fresh keypress resets this resource (dropping the previous `Task<_>`)
+/// before spawning the next one.
+#[derive(Resource, Default)]
+struct PendingVerification {
+    seed: Option<u64>,
+    handle: Option<Task<SolverResult>>,
+}
+
+// ---------------------------------------------------------------------------
+// Constants
+// ---------------------------------------------------------------------------
+
+/// Frames of no-keypress activity before the solver task is spawned.
+/// 12 frames ≈ 200 ms at 60 Hz — long enough to avoid thrashing on fast
+/// typists but short enough to feel responsive.
+const DEBOUNCE_FRAMES: u32 = 12;
+
+/// Maximum decimal digits accepted. 20 covers all of u64::MAX (18,446,744,073,709,551,615).
+const MAX_SEED_DIGITS: usize = 20;
+
+// ---------------------------------------------------------------------------
+// Plugin
+// ---------------------------------------------------------------------------
+
+/// Registers all play-by-seed systems and resources.
+pub struct PlayBySeedPlugin;
+
+impl Plugin for PlayBySeedPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<PendingVerification>()
+            .add_message::<StartPlayBySeedRequestEvent>()
+            .add_message::<NewGameRequestEvent>()
+            .add_systems(
+                Update,
+                (
+                    handle_open_dialog,
+                    handle_text_input,
+                    tick_debounce_and_spawn_solver_task,
+                    poll_solver_task,
+                    handle_confirm,
+                    handle_cancel,
+                )
+                    .chain()
+                    // Fire before GameMutation so `handle_confirm`'s
+                    // NewGameRequestEvent is processed on the same frame.
+                    .before(GameMutation),
+            );
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Systems
+// ---------------------------------------------------------------------------
+
+/// Spawns the seed-input dialog when `StartPlayBySeedRequestEvent` fires.
+fn handle_open_dialog(
+    mut commands: Commands,
+    mut requests: MessageReader<StartPlayBySeedRequestEvent>,
+    font_res: Option<Res<FontResource>>,
+    existing: Query<(), With<PlayBySeedScreen>>,
+) {
+    if requests.read().count() == 0 {
+        return;
+    }
+    // Guard against double-spawn (e.g. two events in one frame).
+    if !existing.is_empty() {
+        return;
+    }
+    let font = font_res.as_deref();
+    let font_handle = font.map(|f| f.0.clone()).unwrap_or_default();
+
+    let scrim = spawn_modal(&mut commands, PlayBySeedScreen, Z_MODAL_PANEL, |card| {
+        spawn_modal_header(card, "Play by Seed", font);
+        spawn_modal_body_text(
+            card,
+            "Enter a number to play that specific deal.",
+            TEXT_SECONDARY,
+            font,
+        );
+
+        // Input field — a bordered box that shows the typed digits.
+        card.spawn((
+            Node {
+                width: Val::Percent(100.0),
+                padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_2),
+                border: UiRect::all(Val::Px(1.0)),
+                border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+                ..default()
+            },
+            BackgroundColor(BG_ELEVATED_PRESSED),
+            BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
+            SeedInputBuffer::default(),
+        ))
+        .with_children(|field| {
+            field.spawn((
+                SeedInputDisplay,
+                Text::new(""),
+                TextFont {
+                    font: font_handle.clone(),
+                    font_size: TYPE_BODY_LG,
+                    ..default()
+                },
+                TextColor(TEXT_DISABLED),
+            ));
+        });
+
+        // Solver verdict badge — updates as solver runs.
+        card.spawn((
+            SolverVerdictBadge,
+            Text::new("Type a number"),
+            TextFont {
+                font: font_handle,
+                font_size: TYPE_BODY_LG,
+                ..default()
+            },
+            TextColor(TEXT_SECONDARY),
+        ));
+
+        spawn_modal_actions(card, |row| {
+            spawn_modal_button(
+                row,
+                PlayBySeedCancelButton,
+                "Cancel",
+                Some("Esc"),
+                ButtonVariant::Secondary,
+                font,
+            );
+            spawn_modal_button(
+                row,
+                PlayBySeedConfirmButton,
+                "Play",
+                Some("Enter"),
+                ButtonVariant::Primary,
+                font,
+            );
+        });
+    });
+
+    // Play-by-Seed is read-only input — opt into click-outside-to-dismiss.
+    commands.entity(scrim).insert(ScrimDismissible);
+}
+
+/// Appends decimal digits and handles Backspace while the dialog is open.
+fn handle_text_input(
+    keys: Res<ButtonInput<KeyCode>>,
+    screen: Query<(), With<PlayBySeedScreen>>,
+    mut buffers: Query<&mut SeedInputBuffer>,
+    mut displays: Query<(&mut Text, &mut TextColor), With<SeedInputDisplay>>,
+    mut pending: ResMut<PendingVerification>,
+) {
+    if screen.is_empty() {
+        return;
+    }
+    let Ok(mut buf) = buffers.single_mut() else {
+        return;
+    };
+
+    let digit_keys = [
+        (KeyCode::Digit0, '0'),
+        (KeyCode::Digit1, '1'),
+        (KeyCode::Digit2, '2'),
+        (KeyCode::Digit3, '3'),
+        (KeyCode::Digit4, '4'),
+        (KeyCode::Digit5, '5'),
+        (KeyCode::Digit6, '6'),
+        (KeyCode::Digit7, '7'),
+        (KeyCode::Digit8, '8'),
+        (KeyCode::Digit9, '9'),
+        (KeyCode::Numpad0, '0'),
+        (KeyCode::Numpad1, '1'),
+        (KeyCode::Numpad2, '2'),
+        (KeyCode::Numpad3, '3'),
+        (KeyCode::Numpad4, '4'),
+        (KeyCode::Numpad5, '5'),
+        (KeyCode::Numpad6, '6'),
+        (KeyCode::Numpad7, '7'),
+        (KeyCode::Numpad8, '8'),
+        (KeyCode::Numpad9, '9'),
+    ];
+
+    let mut changed = false;
+
+    for (key, ch) in digit_keys {
+        if keys.just_pressed(key) && buf.text.len() < MAX_SEED_DIGITS {
+            // Drop a leading zero unless the buffer is empty (prevents "007").
+            if ch == '0' && buf.text.is_empty() {
+                continue;
+            }
+            buf.text.push(ch);
+            changed = true;
+        }
+    }
+
+    if keys.just_pressed(KeyCode::Backspace) && !buf.text.is_empty() {
+        buf.text.pop();
+        changed = true;
+    }
+
+    if changed {
+        buf.frames_since_change = 0;
+        // Cancel any in-flight solver task — its seed is now stale.
+        *pending = PendingVerification::default();
+
+        // Update the display node.
+        if let Ok((mut text, mut color)) = displays.single_mut() {
+            if buf.text.is_empty() {
+                text.0 = String::new();
+                color.0 = TEXT_DISABLED;
+            } else {
+                text.0 = buf.text.clone();
+                color.0 = TEXT_PRIMARY;
+            }
+        }
+    }
+}
+
+/// Increments the debounce counter each frame and spawns the solver task
+/// once the counter passes [`DEBOUNCE_FRAMES`] and the buffer holds a
+/// valid u64.
+fn tick_debounce_and_spawn_solver_task(
+    screen: Query<(), With<PlayBySeedScreen>>,
+    mut buffers: Query<&mut SeedInputBuffer>,
+    mut pending: ResMut<PendingVerification>,
+    mut badges: Query<(&mut Text, &mut TextColor), With<SolverVerdictBadge>>,
+    settings: Option<Res<SettingsResource>>,
+) {
+    if screen.is_empty() {
+        return;
+    }
+    let Ok(mut buf) = buffers.single_mut() else {
+        return;
+    };
+
+    // Always update the badge when the buffer is empty.
+    if buf.text.is_empty() {
+        if let Ok((mut text, mut color)) = badges.single_mut() {
+            text.0 = "Type a number".to_string();
+            color.0 = TEXT_SECONDARY;
+        }
+        return;
+    }
+
+    // Don't spawn if a task is already running for this seed.
+    let parsed = buf.text.parse::<u64>().ok();
+    if pending.handle.is_some() && pending.seed == parsed {
+        return;
+    }
+
+    buf.frames_since_change = buf.frames_since_change.saturating_add(1);
+    if buf.frames_since_change < DEBOUNCE_FRAMES {
+        return;
+    }
+
+    let Some(seed) = parsed else {
+        return;
+    };
+
+    let draw_mode = settings
+        .as_ref()
+        .map_or(DrawMode::DrawOne, |s| s.0.draw_mode.clone());
+    let cfg = SolverConfig::default();
+    let task = AsyncComputeTaskPool::get()
+        .spawn(async move { try_solve(seed, draw_mode, &cfg) });
+
+    pending.seed = Some(seed);
+    pending.handle = Some(task);
+
+    if let Ok((mut text, mut color)) = badges.single_mut() {
+        text.0 = "Verifying\u{2026}".to_string();
+        color.0 = TEXT_SECONDARY;
+    }
+}
+
+/// Polls the in-flight solver task and updates the verdict badge on completion.
+fn poll_solver_task(
+    mut pending: ResMut<PendingVerification>,
+    mut badges: Query<(&mut Text, &mut TextColor), With<SolverVerdictBadge>>,
+) {
+    let Some(handle) = pending.handle.as_mut() else {
+        return;
+    };
+    let Some(result) = future::block_on(future::poll_once(handle)) else {
+        return;
+    };
+    pending.handle = None;
+
+    let Ok((mut text, mut color)) = badges.single_mut() else {
+        return;
+    };
+    match result {
+        SolverResult::Winnable => {
+            text.0 = "\u{2713} Provably winnable".to_string();
+            color.0 = ACCENT_PRIMARY;
+        }
+        SolverResult::Inconclusive => {
+            text.0 = "? Likely winnable (search timed out)".to_string();
+            color.0 = TEXT_SECONDARY;
+        }
+        SolverResult::Unwinnable => {
+            text.0 = "\u{2717} Provably unwinnable".to_string();
+            color.0 = TEXT_DISABLED;
+        }
+    }
+}
+
+/// Fires [`NewGameRequestEvent`] with the parsed seed when Play is clicked
+/// or `Enter` is pressed, then despawns the dialog. Does nothing when the
+/// buffer is empty.
+fn handle_confirm(
+    mut commands: Commands,
+    keys: Res<ButtonInput<KeyCode>>,
+    buttons: Query<&Interaction, (With<PlayBySeedConfirmButton>, Changed<Interaction>)>,
+    buffers: Query<&SeedInputBuffer>,
+    screen: Query<Entity, With<PlayBySeedScreen>>,
+    mut new_game: MessageWriter<NewGameRequestEvent>,
+) {
+    if screen.is_empty() {
+        return;
+    }
+
+    let click = buttons.iter().any(|i| *i == Interaction::Pressed);
+    let enter = keys.just_pressed(KeyCode::Enter) || keys.just_pressed(KeyCode::NumpadEnter);
+    if !click && !enter {
+        return;
+    }
+
+    let Ok(buf) = buffers.single() else { return };
+    let Ok(seed) = buf.text.parse::<u64>() else { return };
+
+    new_game.write(NewGameRequestEvent {
+        seed: Some(seed),
+        mode: None,
+        confirmed: false,
+    });
+
+    for entity in &screen {
+        commands.entity(entity).despawn();
+    }
+}
+
+/// Despawns the dialog on Cancel click or `Escape`.
+fn handle_cancel(
+    mut commands: Commands,
+    keys: Res<ButtonInput<KeyCode>>,
+    buttons: Query<&Interaction, (With<PlayBySeedCancelButton>, Changed<Interaction>)>,
+    screen: Query<Entity, With<PlayBySeedScreen>>,
+    other_scrims: Query<(), (With<crate::ui_modal::ModalScrim>, Without<PlayBySeedScreen>)>,
+) {
+    if screen.is_empty() {
+        return;
+    }
+
+    let click = buttons.iter().any(|i| *i == Interaction::Pressed);
+    // Esc only closes this dialog when it is the topmost modal.
+    let esc = keys.just_pressed(KeyCode::Escape) && other_scrims.is_empty();
+    if !click && !esc {
+        return;
+    }
+
+    for entity in &screen {
+        commands.entity(entity).despawn();
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::game_plugin::GamePlugin;
+    use crate::table_plugin::TablePlugin;
+
+    fn headless_app() -> App {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(GamePlugin)
+            .add_plugins(TablePlugin)
+            .add_plugins(PlayBySeedPlugin);
+        app.init_resource::<ButtonInput<KeyCode>>();
+        app.update();
+        app
+    }
+
+    fn open_dialog(app: &mut App) {
+        app.world_mut()
+            .write_message(StartPlayBySeedRequestEvent);
+        app.update();
+    }
+
+    fn press_key(app: &mut App, key: KeyCode) {
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(key);
+        app.update();
+        // Simulate what Bevy's PreUpdate input system does: flush just_pressed /
+        // just_released so stale key state doesn't bleed into the next frame.
+        let mut input = app.world_mut().resource_mut::<ButtonInput<KeyCode>>();
+        input.release(key);
+        input.clear();
+    }
+
+    fn dialog_present(app: &mut App) -> bool {
+        app.world_mut()
+            .query::<&PlayBySeedScreen>()
+            .iter(app.world())
+            .next()
+            .is_some()
+    }
+
+    fn read_buffer_text(app: &mut App) -> String {
+        let mut q = app.world_mut().query::<&SeedInputBuffer>();
+        q.iter(app.world())
+            .next()
+            .map(|b| b.text.clone())
+            .unwrap_or_default()
+    }
+
+    #[test]
+    fn dialog_spawns_on_request() {
+        let mut app = headless_app();
+        assert!(!dialog_present(&mut app));
+        open_dialog(&mut app);
+        assert!(dialog_present(&mut app));
+    }
+
+    #[test]
+    fn digit_keys_append_to_buffer() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        press_key(&mut app, KeyCode::Digit4);
+        press_key(&mut app, KeyCode::Digit2);
+
+        assert_eq!(read_buffer_text(&mut app), "42");
+    }
+
+    #[test]
+    fn backspace_removes_last_char() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        press_key(&mut app, KeyCode::Digit4);
+        press_key(&mut app, KeyCode::Digit2);
+        press_key(&mut app, KeyCode::Backspace);
+
+        assert_eq!(read_buffer_text(&mut app), "4");
+    }
+
+    #[test]
+    fn confirm_does_nothing_when_buffer_is_empty() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        // Simulate Enter with empty buffer.
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::Enter);
+        app.update();
+
+        let msgs = app.world().resource::<Messages<NewGameRequestEvent>>();
+        let mut cursor = msgs.get_cursor();
+        assert!(cursor.read(msgs).next().is_none(), "no NewGameRequestEvent when buffer empty");
+        // Dialog should still be open.
+        assert!(dialog_present(&mut app));
+    }
+
+    #[test]
+    fn confirm_writes_new_game_request_with_parsed_seed() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        press_key(&mut app, KeyCode::Digit4);
+        press_key(&mut app, KeyCode::Digit2);
+
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::Enter);
+        app.update();
+
+        let msgs = app.world().resource::<Messages<NewGameRequestEvent>>();
+        let mut cursor = msgs.get_cursor();
+        let fired: Vec<_> = cursor.read(msgs).copied().collect();
+        assert_eq!(fired.len(), 1);
+        assert_eq!(fired[0].seed, Some(42));
+        assert_eq!(fired[0].mode, None);
+        assert!(!fired[0].confirmed);
+
+        // Dialog should be gone.
+        assert!(!dialog_present(&mut app));
+    }
+
+    #[test]
+    fn cancel_despawns_dialog_without_new_game_request() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        press_key(&mut app, KeyCode::Escape);
+
+        assert!(!dialog_present(&mut app));
+
+        let msgs = app.world().resource::<Messages<NewGameRequestEvent>>();
+        let mut cursor = msgs.get_cursor();
+        assert!(cursor.read(msgs).next().is_none());
+    }
+
+    #[test]
+    fn solver_task_spawns_after_debounce_window() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        press_key(&mut app, KeyCode::Digit4);
+        press_key(&mut app, KeyCode::Digit2);
+
+        // Debounce window — no task yet.
+        for _ in 0..DEBOUNCE_FRAMES {
+            app.update();
+        }
+
+        let pending = app.world().resource::<PendingVerification>();
+        assert!(pending.handle.is_some(), "solver task should have been spawned after debounce");
+        assert_eq!(pending.seed, Some(42));
+    }
+
+    #[test]
+    fn keypress_mid_flight_cancels_previous_solver_task() {
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        press_key(&mut app, KeyCode::Digit4);
+        press_key(&mut app, KeyCode::Digit2);
+
+        // Let the debounce fire.
+        for _ in 0..DEBOUNCE_FRAMES {
+            app.update();
+        }
+        assert!(app.world().resource::<PendingVerification>().handle.is_some());
+
+        // New keypress should cancel the in-flight task.
+        press_key(&mut app, KeyCode::Digit3);
+        assert!(app.world().resource::<PendingVerification>().handle.is_none());
+        assert_eq!(app.world().resource::<PendingVerification>().seed, None);
+    }
+
+    #[test]
+    fn solver_task_completes_and_updates_badge() {
+        use std::time::Instant;
+
+        let mut app = headless_app();
+        open_dialog(&mut app);
+
+        // Seed 42 — solver will return some verdict.
+        press_key(&mut app, KeyCode::Digit4);
+        press_key(&mut app, KeyCode::Digit2);
+
+        // Wait for the debounce to spawn the task.
+        for _ in 0..DEBOUNCE_FRAMES {
+            app.update();
+        }
+
+        // Poll until the solver task resolves (cap at 15 s wall-clock).
+        let deadline = Instant::now() + std::time::Duration::from_secs(15);
+        while app.world().resource::<PendingVerification>().handle.is_some()
+            && Instant::now() < deadline
+        {
+            app.update();
+            std::thread::yield_now();
+        }
+
+        // Badge text should no longer read "Verifying…".
+        let badge_text = app
+            .world_mut()
+            .query::<(&Text, &SolverVerdictBadge)>()
+            .iter(app.world())
+            .next()
+            .map(|(t, _)| t.0.clone())
+            .unwrap_or_default();
+        assert_ne!(badge_text, "Verifying\u{2026}", "badge should have resolved to a verdict");
+        assert_ne!(badge_text, "Type a number", "badge should show verdict, not idle state");
+    }
+}

solitaire_engine/src/radial_menu.rs

@@ -42,6 +42,7 @@
 //! real `PrimaryWindow` / camera, since `MinimalPlugins` provides
 //! neither.
 
+use bevy::input::touch::Touches;
 use bevy::input::ButtonInput;
 use bevy::math::Vec2;
 use bevy::prelude::*;
@@ -56,7 +57,13 @@ use crate::events::MoveRequestEvent;
 use crate::layout::{Layout, LayoutResource};
 use crate::pause_plugin::PausedResource;
 use crate::resources::{DragState, GameStateResource};
-use crate::ui_theme::{ACCENT_PRIMARY, BORDER_STRONG, BORDER_SUBTLE, STATE_SUCCESS};
+use crate::settings_plugin::SettingsResource;
+use crate::ui_theme::{ACCENT_PRIMARY, BORDER_STRONG, BORDER_SUBTLE, BORDER_SUBTLE_HC, STATE_SUCCESS};
+
+/// Seconds a finger must be held on a face-up card (without crossing the
+/// drag threshold) before the radial menu opens. Matches Android's long-press
+/// gesture recogniser default.
+const LONG_PRESS_SECS: f32 = 0.5;
 
 /// Sprite-space `Transform.z` for radial-menu overlay sprites.
 ///
@@ -180,6 +187,7 @@ impl Plugin for RadialMenuPlugin {
                 Update,
                 (
                     radial_open_on_right_click,
+                    radial_open_on_long_press,
                     radial_track_cursor,
                     radial_handle_release_or_cancel,
                     radial_redraw_overlay,
@@ -445,6 +453,68 @@ fn radial_open_on_right_click(
     };
 }
 
+/// Opens the radial menu after a sustained touch hold on a face-up card.
+///
+/// Counts up while the touch is down, the drag threshold has not been
+/// crossed, and the radial is not yet active. Fires after
+/// [`LONG_PRESS_SECS`] (0.5 s). The timer resets whenever these
+/// conditions are not met, so lifting, committing a drag, or the radial
+/// already being open all clear it cleanly.
+#[allow(clippy::too_many_arguments)]
+fn radial_open_on_long_press(
+    time: Res<Time>,
+    mut hold_timer: Local<f32>,
+    drag: Res<DragState>,
+    paused: Option<Res<PausedResource>>,
+    touches: Option<Res<Touches>>,
+    cameras: Query<(&Camera, &GlobalTransform)>,
+    layout: Option<Res<LayoutResource>>,
+    game: Option<Res<GameStateResource>>,
+    mut state: ResMut<RightClickRadialState>,
+) {
+    // Guard: only count while a touch is down, uncommitted, and radial is idle.
+    let active_id = drag.active_touch_id;
+    if active_id.is_none() || drag.committed || state.is_active() || paused.is_some_and(|p| p.0) {
+        *hold_timer = 0.0;
+        return;
+    }
+
+    *hold_timer += time.delta_secs();
+    if *hold_timer < LONG_PRESS_SECS {
+        return;
+    }
+    *hold_timer = 0.0;
+
+    // Resolve current touch world position.
+    let Some(touches) = touches else { return };
+    let Some(touch) = touches.iter().find(|t| t.id() == active_id.unwrap()) else {
+        return;
+    };
+    let Some((camera, cam_xf)) = cameras.single().ok() else { return };
+    let Some(world) = camera.viewport_to_world_2d(cam_xf, touch.position()).ok() else {
+        return;
+    };
+    let Some(layout) = layout else { return };
+    let Some(game) = game else { return };
+
+    let Some((source_pile, card)) = find_top_face_up_card_at(world, &game.0, &layout.0) else {
+        return;
+    };
+    let dests = legal_destinations_for_card(&card, &source_pile, &game.0);
+    if dests.is_empty() {
+        return;
+    }
+    let legal_destinations = build_radial_destinations(world, dests);
+    *state = RightClickRadialState::Active {
+        source_pile,
+        count: 1,
+        cards: vec![card.id],
+        legal_destinations,
+        centre: world,
+        hovered_index: None,
+    };
+}
+
 /// Each frame while `Active`, updates `hovered_index` based on the
 /// current cursor position. Cheap — just re-runs hit-testing against
 /// the precomputed anchors. The overlay redraw system reads this index
@@ -453,6 +523,7 @@ fn radial_track_cursor(
     cursor_override: Option<Res<RadialCursorOverride>>,
     windows: Query<&Window, With<PrimaryWindow>>,
     cameras: Query<(&Camera, &GlobalTransform)>,
+    touches: Option<Res<Touches>>,
     mut state: ResMut<RightClickRadialState>,
 ) {
     let RightClickRadialState::Active {
@@ -463,21 +534,28 @@ fn radial_track_cursor(
     else {
         return;
     };
-    let Some(world) = cursor_world(cursor_override.as_ref(), &windows, &cameras) else {
+    // Cursor first (mouse / test override); fall back to first active touch
-        return;
+    // so the player can slide their held finger over radial icons on Android.
-    };
+    let world = cursor_world(cursor_override.as_ref(), &windows, &cameras).or_else(|| {
+        let (camera, cam_xf) = cameras.single().ok()?;
+        let touch_pos = touches.as_ref()?.iter().next()?.position();
+        camera.viewport_to_world_2d(cam_xf, touch_pos).ok()
+    });
+    let Some(world) = world else { return };
     let anchors: Vec<Vec2> = legal_destinations.iter().map(|(_, a)| *a).collect();
     *hovered_index = radial_hovered_index(world, &anchors);
 }
 
-/// Handles three exit conditions while `Active`:
+/// Handles exit conditions while `Active`:
 /// 1. Right-mouse release → confirm if hovering, otherwise cancel.
-/// 2. `Escape` → cancel.
+/// 2. Touch lift (`Touches::iter_just_released`) → confirm if hovering, cancel otherwise.
-/// 3. Left-mouse press → cancel (keeps the existing drag pipeline clean).
+/// 3. `Escape` → cancel.
+/// 4. Left-mouse press → cancel (keeps the existing drag pipeline clean).
 #[allow(clippy::too_many_arguments)]
 fn radial_handle_release_or_cancel(
     buttons: Option<Res<ButtonInput<MouseButton>>>,
     keys: Option<Res<ButtonInput<KeyCode>>>,
+    touches: Option<Res<Touches>>,
     mut state: ResMut<RightClickRadialState>,
     mut moves: MessageWriter<MoveRequestEvent>,
 ) {
@@ -494,13 +572,18 @@ fn radial_handle_release_or_cancel(
     let left_pressed = buttons
         .as_ref()
         .is_some_and(|b| b.just_pressed(MouseButton::Left));
+    // Finger lift: any touch that ended or was cancelled this frame.
+    let touch_ended = touches.as_ref().is_some_and(|t| {
+        t.iter_just_released().next().is_some() || t.iter_just_canceled().next().is_some()
+    });
 
-    if !escape_pressed && !right_released && !left_pressed {
+    if !escape_pressed && !right_released && !left_pressed && !touch_ended {
         return;
     }
 
-    // On confirm, fire a MoveRequestEvent. On any other exit, just clear.
+    // On confirm (right-release or touch-lift while hovering), fire a move.
-    if right_released
+    let confirm = right_released || touch_ended;
+    if confirm
         && let RightClickRadialState::Active {
             source_pile,
             count,
@@ -533,8 +616,17 @@ fn radial_handle_release_or_cancel(
 
 /// Despawns and respawns the radial overlay sprites every frame the
 /// state is `Active`; despawns them when the state returns to `Idle`.
+///
+/// Reads [`SettingsResource`] so the focused-icon outline can boost to
+/// [`BORDER_SUBTLE_HC`] under high-contrast mode. Per-frame respawn is
+/// the simplest place to fold HC in: this is the only system that
+/// owns the rim sprite, so there's no parallel paint path to fight.
+/// ([`HighContrastBorder`](crate::ui_theme::HighContrastBorder) doesn't
+/// apply because the rim is a `Sprite`, not a UI node with
+/// `BorderColor`, and the entities don't persist across frames.)
 fn radial_redraw_overlay(
     state: Res<RightClickRadialState>,
+    settings: Option<Res<SettingsResource>>,
     mut commands: Commands,
     existing_icons: Query<Entity, With<RadialIcon>>,
     existing_centres: Query<Entity, With<RadialCentre>>,
@@ -569,13 +661,12 @@ fn radial_redraw_overlay(
         Transform::from_xyz(centre.x, centre.y, Z_RADIAL_MENU + 0.01),
     ));
 
+    let high_contrast = settings.as_ref().is_some_and(|s| s.0.high_contrast_mode);
     for (i, (_pile, anchor)) in legal_destinations.iter().enumerate() {
         let focused = *hovered_index == Some(i);
         let scale = if focused { RADIAL_HOVER_SCALE } else { 1.0 };
         let fill = if focused { STATE_SUCCESS } else { ACCENT_PRIMARY };
-        // Hovered icon gets a strong yellow rim; resting icons get a
+        let outline = radial_rim_outline(focused, high_contrast);
-        // muted purple rim so the focused one reads as the obvious target.
-        let outline = if focused { BORDER_STRONG } else { BORDER_SUBTLE };
 
         commands
             .spawn((
@@ -606,6 +697,27 @@ fn radial_redraw_overlay(
     }
 }
 
+/// Pure decision logic for the radial-icon rim outline colour.
+///
+/// Resting icons always carry [`BORDER_SUBTLE`] so the focused icon
+/// reads as the obvious target. Under high-contrast mode the focused
+/// rim boosts to [`BORDER_SUBTLE_HC`] (`#a0a0a0`) instead of
+/// [`BORDER_STRONG`] (`#505050`) — naive marker substitution via
+/// [`HighContrastBorder`](crate::ui_theme::HighContrastBorder) would
+/// invert the hierarchy because the resting colour
+/// (`#353535`) is darker than `BORDER_STRONG`. This shape keeps the
+/// focused rim *more* visible under HC, not less.
+///
+/// Factored out as a pure function so the truth-table is unit-testable
+/// without spinning up the per-frame respawn system.
+fn radial_rim_outline(focused: bool, high_contrast: bool) -> Color {
+    match (focused, high_contrast) {
+        (true, true) => BORDER_SUBTLE_HC,
+        (true, false) => BORDER_STRONG,
+        (false, _) => BORDER_SUBTLE,
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Tests
 // ---------------------------------------------------------------------------
@@ -689,7 +801,7 @@ mod tests {
 
     fn install_resources(app: &mut App, state: GameState, layout_window: Vec2, cursor: Vec2) {
         app.insert_resource(GameStateResource(state));
-        app.insert_resource(LayoutResource(compute_layout(layout_window)));
+        app.insert_resource(LayoutResource(compute_layout(layout_window, 0.0, 0.0)));
         app.world_mut().resource_mut::<RadialCursorOverride>().0 = Some(cursor);
     }
 
@@ -801,7 +913,7 @@ mod tests {
     fn right_click_press_on_face_up_card_opens_radial() {
         let mut app = radial_test_app();
         let layout_window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(layout_window);
+        let layout = compute_layout(layout_window, 0.0, 0.0);
         let ace_pos = layout.pile_positions[&PileType::Tableau(0)];
 
         install_resources(&mut app, ace_only_state(), layout_window, ace_pos);
@@ -838,7 +950,7 @@ mod tests {
     fn right_click_release_over_destination_fires_move_request() {
         let mut app = radial_test_app();
         let layout_window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(layout_window);
+        let layout = compute_layout(layout_window, 0.0, 0.0);
         let ace_pos = layout.pile_positions[&PileType::Tableau(0)];
 
         install_resources(&mut app, ace_only_state(), layout_window, ace_pos);
@@ -877,7 +989,7 @@ mod tests {
     fn right_click_release_outside_any_destination_cancels() {
         let mut app = radial_test_app();
         let layout_window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(layout_window);
+        let layout = compute_layout(layout_window, 0.0, 0.0);
         let ace_pos = layout.pile_positions[&PileType::Tableau(0)];
 
         install_resources(&mut app, ace_only_state(), layout_window, ace_pos);
@@ -904,7 +1016,7 @@ mod tests {
     fn escape_cancels_active_radial() {
         let mut app = radial_test_app();
         let layout_window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(layout_window);
+        let layout = compute_layout(layout_window, 0.0, 0.0);
         let ace_pos = layout.pile_positions[&PileType::Tableau(0)];
 
         install_resources(&mut app, ace_only_state(), layout_window, ace_pos);
@@ -927,7 +1039,7 @@ mod tests {
     fn right_click_on_face_down_card_does_not_open_radial() {
         let mut app = radial_test_app();
         let layout_window = Vec2::new(1280.0, 800.0);
-        let layout = compute_layout(layout_window);
+        let layout = compute_layout(layout_window, 0.0, 0.0);
         let king_pos = layout.pile_positions[&PileType::Tableau(0)];
 
         install_resources(&mut app, face_down_only_state(), layout_window, king_pos);
@@ -940,4 +1052,33 @@ mod tests {
             "face-down cards must not open the radial"
         );
     }
+
+    // -----------------------------------------------------------------------
+    // radial_rim_outline — accessibility / high-contrast truth table
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn rim_resting_uses_subtle_outline_without_hc() {
+        assert_eq!(radial_rim_outline(false, false), BORDER_SUBTLE);
+    }
+
+    #[test]
+    fn rim_focused_uses_strong_outline_without_hc() {
+        assert_eq!(radial_rim_outline(true, false), BORDER_STRONG);
+    }
+
+    #[test]
+    fn rim_focused_boosts_to_subtle_hc_under_hc() {
+        assert_eq!(radial_rim_outline(true, true), BORDER_SUBTLE_HC);
+    }
+
+    #[test]
+    fn rim_resting_stays_subtle_under_hc_to_preserve_hierarchy() {
+        // Naive marker substitution would also flip the resting outline
+        // to BORDER_SUBTLE_HC, which is *lighter* than BORDER_STRONG —
+        // that would invert the focused/resting hierarchy. Holding the
+        // resting colour at BORDER_SUBTLE keeps the focused icon the
+        // obvious target under HC.
+        assert_eq!(radial_rim_outline(false, true), BORDER_SUBTLE);
+    }
 }

solitaire_engine/src/replay_playback.rs

@@ -42,7 +42,7 @@
 use bevy::prelude::*;
 use solitaire_data::{Replay, ReplayMove};
 
-use crate::events::{DrawRequestEvent, MoveRequestEvent, StateChangedEvent};
+use crate::events::{DrawRequestEvent, MoveRequestEvent, StateChangedEvent, UndoRequestEvent};
 use crate::game_plugin::{GameMutation, RecordingReplay};
 use crate::resources::GameStateResource;
 use crate::settings_plugin::SettingsResource;
@@ -119,6 +119,15 @@ pub enum ReplayPlaybackState {
         cursor: usize,
         /// Seconds remaining until the next move is dispatched.
         secs_to_next: f32,
+        /// `true` while playback is paused — `tick_replay_playback`
+        /// skips the `secs_to_next` decrement entirely while this is
+        /// set, so the cursor and the timer freeze together. The
+        /// overlay stays mounted (`is_playing()` still returns
+        /// `true`) so the player can see the paused state and the
+        /// Resume / Step controls. Stepping while paused fires the
+        /// next move directly via [`step_replay_playback`] and
+        /// leaves the paused flag untouched.
+        paused: bool,
     },
     /// The replay finished playing back. The overlay swaps the banner
     /// label to "Replay complete" until [`auto_clear_completed_replay`]
@@ -194,6 +203,7 @@ pub fn start_replay_playback(
         replay,
         cursor: 0,
         secs_to_next: REPLAY_MOVE_INTERVAL_SECS,
+        paused: false,
     };
 }
 
@@ -219,6 +229,107 @@ pub fn stop_replay_playback(
     **state = ReplayPlaybackState::Inactive;
 }
 
+/// Toggle the `paused` flag on the active playback. No-op when not
+/// `Playing` (i.e. `Inactive` or `Completed`) — pause has no meaning
+/// in those states. Returns the new paused value, or `None` if the
+/// state wasn't `Playing`.
+pub fn toggle_pause_replay_playback(state: &mut ResMut<ReplayPlaybackState>) -> Option<bool> {
+    if let ReplayPlaybackState::Playing { paused, .. } = state.as_mut() {
+        *paused = !*paused;
+        Some(*paused)
+    } else {
+        None
+    }
+}
+
+/// Advance playback by exactly one move. Only meaningful while paused
+/// — when called on an unpaused playback it would race the
+/// `tick_replay_playback` loop. Returns `true` when a move was fired,
+/// `false` when no-op (state isn't `Playing { paused: true }` or the
+/// cursor is already at the end of the move list).
+///
+/// Stepping the last move transitions the state to `Completed` on
+/// the next `tick_replay_playback` frame — same end-of-list path the
+/// normal advance loop takes.
+pub fn step_replay_playback(
+    state: &mut ResMut<ReplayPlaybackState>,
+    moves_writer: &mut MessageWriter<MoveRequestEvent>,
+    draws_writer: &mut MessageWriter<DrawRequestEvent>,
+) -> bool {
+    let ReplayPlaybackState::Playing {
+        replay,
+        cursor,
+        paused: true,
+        ..
+    } = state.as_mut()
+    else {
+        return false;
+    };
+    if *cursor >= replay.moves.len() {
+        return false;
+    }
+    match &replay.moves[*cursor] {
+        ReplayMove::Move { from, to, count } => {
+            moves_writer.write(MoveRequestEvent {
+                from: from.clone(),
+                to: to.clone(),
+                count: *count,
+            });
+        }
+        ReplayMove::StockClick => {
+            draws_writer.write(DrawRequestEvent);
+        }
+    }
+    *cursor += 1;
+    true
+}
+
+/// Steps the replay **backwards** by exactly one move while paused.
+///
+/// Strategy: the live game's undo system is the source of truth for
+/// reversing moves. Every move the replay forward-stepped (via
+/// [`step_replay_playback`] or the auto-advance loop in
+/// [`tick_replay_playback`]) was dispatched as a canonical
+/// [`MoveRequestEvent`] / [`DrawRequestEvent`], which the game
+/// applied and pushed onto its undo stack. So a backwards step here
+/// is simply: decrement the cursor (so the about-to-apply move
+/// re-points at the one we're rewinding past) and fire an
+/// [`UndoRequestEvent`] so the game reverses its most-recent move
+/// next frame.
+///
+/// Hard-gated to the paused state via destructure pattern —
+/// matches the existing [`step_replay_playback`] gate so the
+/// player can only scrub one direction at a time and the tick
+/// loop never races a manual rewind.
+///
+/// Returns `false` and is a no-op in three cases:
+/// - State isn't `Playing` (no replay attached).
+/// - State is `Playing` but not paused (the tick loop owns the cursor).
+/// - Cursor is already at 0 (nothing to rewind past).
+///
+/// Returns `true` on a successful step; the actual game-state
+/// reversal happens next frame when `handle_undo` reads the
+/// `UndoRequestEvent`.
+pub fn step_backwards_replay_playback(
+    state: &mut ResMut<ReplayPlaybackState>,
+    undo_writer: &mut MessageWriter<UndoRequestEvent>,
+) -> bool {
+    let ReplayPlaybackState::Playing {
+        cursor,
+        paused: true,
+        ..
+    } = state.as_mut()
+    else {
+        return false;
+    };
+    if *cursor == 0 {
+        return false;
+    }
+    *cursor -= 1;
+    undo_writer.write(UndoRequestEvent);
+    true
+}
+
 /// Tick system. Runs every frame; only does work when
 /// [`ReplayPlaybackState::is_playing`].
 ///
@@ -249,8 +360,15 @@ fn tick_replay_playback(
         replay,
         cursor,
         secs_to_next,
+        paused,
     } = state.as_mut()
     {
+        // While paused, the cursor and the timer freeze together —
+        // skip the decrement entirely so resuming starts the next
+        // move from a full `secs_to_next` window. Stepping (handled
+        // separately) fires moves directly without touching this
+        // path.
+        if !*paused {
             *secs_to_next -= dt;
             while *secs_to_next <= 0.0 && *cursor < replay.moves.len() {
                 match &replay.moves[*cursor] {
@@ -273,6 +391,7 @@ fn tick_replay_playback(
                 transition_to_completed = true;
             }
         }
+    }
 
     if transition_to_completed {
         *state = ReplayPlaybackState::Completed;

solitaire_engine/src/safe_area.rs

@@ -0,0 +1,248 @@
+//! Safe-area insets.
+//!
+//! Reports the OS-reserved regions around the playable surface (status
+//! bar at the top, gesture / navigation bar at the bottom on Android,
+//! display cutouts, etc.) so UI anchored to a screen edge can avoid
+//! collisions.
+//!
+//! On non-Android targets all four edges report `0.0`. On Android the
+//! values come from `WindowInsets.getInsets(WindowInsets.Type.systemBars())`
+//! via JNI; the call is retried for the first few frames because
+//! `getRootWindowInsets()` only returns useful values after the decor
+//! view has been laid out at least once.
+//!
+//! UI that wants to respect the top inset should tag itself with the
+//! [`SafeAreaAnchoredTop`] marker carrying the layout's original top
+//! offset; [`apply_safe_area_anchors`] re-applies `base_top + insets.top`
+//! whenever the resource changes, so late inset arrival or orientation
+//! changes flow through automatically.
+
+use bevy::prelude::*;
+
+/// Pixel sizes of the system-reserved regions on each edge of the
+/// surface. Zero on desktop.
+#[derive(Resource, Debug, Clone, Copy, Default, PartialEq)]
+pub struct SafeAreaInsets {
+    pub top: f32,
+    pub bottom: f32,
+    pub left: f32,
+    pub right: f32,
+}
+
+impl SafeAreaInsets {
+    /// `true` when any edge has a non-zero reservation. Used by the
+    /// Android polling system to know it can stop querying.
+    pub fn is_populated(&self) -> bool {
+        self.top > 0.0 || self.bottom > 0.0 || self.left > 0.0 || self.right > 0.0
+    }
+}
+
+/// Marker for `Node` entities whose `top` offset should be re-applied
+/// as `base_top + SafeAreaInsets::top`.
+///
+/// `base_top` is the offset the layout would have used on a surface
+/// with no system reservation (i.e. on desktop). The fix-up system
+/// adds the current top inset on top of it whenever the resource
+/// changes.
+#[derive(Component, Debug, Clone, Copy)]
+pub struct SafeAreaAnchoredTop {
+    pub base_top: f32,
+}
+
+pub struct SafeAreaInsetsPlugin;
+
+impl Plugin for SafeAreaInsetsPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<SafeAreaInsets>()
+            .add_systems(Update, apply_safe_area_anchors);
+
+        #[cfg(target_os = "android")]
+        app.add_systems(Update, android::refresh_insets);
+    }
+}
+
+/// Re-applies `base_top + insets.top` to every entity carrying the
+/// [`SafeAreaAnchoredTop`] marker whenever [`SafeAreaInsets`] changes.
+///
+/// Bevy resource change detection (`Res::is_changed`) is `true` on the
+/// frame the resource is inserted and every frame a `ResMut` borrow
+/// occurs. Combined with the Android polling loop short-circuiting
+/// once insets are populated, this runs at most a handful of times in
+/// a session.
+fn apply_safe_area_anchors(
+    insets: Res<SafeAreaInsets>,
+    windows: Query<&Window>,
+    mut q: Query<(&SafeAreaAnchoredTop, &mut Node)>,
+) {
+    if !insets.is_changed() {
+        return;
+    }
+    // Android's WindowInsets API returns physical pixels; Bevy UI's Val::Px
+    // expects logical pixels (≈ dp). Divide by the window scale factor so
+    // the HUD band shifts by the correct number of dp on high-DPI devices.
+    let scale = windows.iter().next().map_or(1.0, |w| w.scale_factor());
+    let top_logical = insets.top / scale;
+    for (anchor, mut node) in &mut q {
+        node.top = Val::Px(anchor.base_top + top_logical);
+    }
+}
+
+#[cfg(target_os = "android")]
+mod android {
+    use super::SafeAreaInsets;
+    use bevy::prelude::*;
+
+    /// Polls Android for safe-area insets until we get a non-zero
+    /// reading, then stops. `getRootWindowInsets()` returns `null` (or
+    /// all-zero `Insets`) until the decor view has been laid out, which
+    /// is typically frame 1–3 of a fresh launch.
+    pub(super) fn refresh_insets(
+        mut insets: ResMut<SafeAreaInsets>,
+        mut tries: Local<u32>,
+    ) {
+        // Cap retries so we don't burn CPU forever on edge-to-edge
+        // devices that genuinely report zero insets.
+        const MAX_TRIES: u32 = 120; // ~2 seconds @ 60 fps
+
+        if *tries >= MAX_TRIES || insets.is_populated() {
+            return;
+        }
+        *tries += 1;
+
+        match query_insets() {
+            Ok(v) if v.is_populated() => {
+                info!(
+                    "safe_area: insets resolved top={} bottom={} left={} right={} (after {} frames)",
+                    v.top, v.bottom, v.left, v.right, *tries
+                );
+                *insets = v;
+            }
+            Ok(_) => {
+                // Layout not ready yet; try again next frame.
+            }
+            Err(e) => {
+                // Don't spam — log once and let polling continue silently.
+                if *tries == 1 {
+                    warn!("safe_area: JNI query failed (will retry): {e}");
+                }
+            }
+        }
+    }
+
+    fn query_insets() -> Result<SafeAreaInsets, String> {
+        use bevy::android::ANDROID_APP;
+        use jni::{objects::JObject, JavaVM};
+
+        let app = ANDROID_APP
+            .get()
+            .ok_or_else(|| "ANDROID_APP not initialized".to_string())?;
+
+        // SAFETY: `vm_as_ptr()` returns the JavaVM* set up by the Android
+        // runtime; valid for the lifetime of the process.
+        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()` returns 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<SafeAreaInsets> {
+            // Window window = activity.getWindow();
+            let window = env
+                .call_method(&activity, "getWindow", "()Landroid/view/Window;", &[])?
+                .l()?;
+
+            // View decor = window.getDecorView();
+            let decor = env
+                .call_method(&window, "getDecorView", "()Landroid/view/View;", &[])?
+                .l()?;
+
+            // WindowInsets insets = decor.getRootWindowInsets();
+            let raw_insets = env
+                .call_method(
+                    &decor,
+                    "getRootWindowInsets",
+                    "()Landroid/view/WindowInsets;",
+                    &[],
+                )?
+                .l()?;
+            if raw_insets.is_null() {
+                return Ok(SafeAreaInsets::default());
+            }
+
+            // int types = WindowInsets.Type.systemBars();
+            // (Static method on the WindowInsets$Type inner class.
+            // Available since API 30 / Android 11.)
+            let type_class = env.find_class("android/view/WindowInsets$Type")?;
+            let bars_type = env
+                .call_static_method(&type_class, "systemBars", "()I", &[])?
+                .i()?;
+
+            // Insets bars = insets.getInsets(types);
+            let bars = env
+                .call_method(
+                    &raw_insets,
+                    "getInsets",
+                    "(I)Landroid/graphics/Insets;",
+                    &[bars_type.into()],
+                )?
+                .l()?;
+
+            // `Insets` exposes `top`, `bottom`, `left`, `right` as public
+            // `int` fields (pixel values, not dp).
+            let top = env.get_field(&bars, "top", "I")?.i()? as f32;
+            let bottom = env.get_field(&bars, "bottom", "I")?.i()? as f32;
+            let left = env.get_field(&bars, "left", "I")?.i()? as f32;
+            let right = env.get_field(&bars, "right", "I")?.i()? as f32;
+
+            Ok(SafeAreaInsets {
+                top,
+                bottom,
+                left,
+                right,
+            })
+        })()
+        .map_err(|e| format!("safe-area JNI: {e}"))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn default_is_zero_and_not_populated() {
+        let i = SafeAreaInsets::default();
+        assert_eq!(i.top, 0.0);
+        assert_eq!(i.bottom, 0.0);
+        assert!(!i.is_populated());
+    }
+
+    #[test]
+    fn is_populated_returns_true_for_any_nonzero_edge() {
+        assert!(SafeAreaInsets {
+            top: 24.0,
+            ..Default::default()
+        }
+        .is_populated());
+        assert!(SafeAreaInsets {
+            bottom: 16.0,
+            ..Default::default()
+        }
+        .is_populated());
+        assert!(SafeAreaInsets {
+            left: 8.0,
+            ..Default::default()
+        }
+        .is_populated());
+        assert!(SafeAreaInsets {
+            right: 8.0,
+            ..Default::default()
+        }
+        .is_populated());
+    }
+}

solitaire_engine/src/settings_plugin.rs

@@ -22,11 +22,17 @@ use solitaire_data::{
     TOOLTIP_DELAY_STEP_SECS,
 };
 
-use crate::events::{InfoToastEvent, ManualSyncRequestEvent, ToggleSettingsRequestEvent};
+use solitaire_data::settings::SyncBackend;
+
+use crate::events::{
+    DeleteAccountRequestEvent, InfoToastEvent, ManualSyncRequestEvent, SyncConfigureRequestEvent,
+    SyncLogoutRequestEvent, ToggleSettingsRequestEvent,
+};
 use crate::font_plugin::FontResource;
 use crate::progress_plugin::ProgressResource;
 use crate::resources::{SettingsScrollPos, SyncStatus, SyncStatusResource};
-use crate::theme::{ThemeThumbnailCache, ThemeThumbnailPair};
+use crate::assets::user_theme_dir;
+use crate::theme::{import_theme, ImportError, ThemeThumbnailCache, ThemeThumbnailPair, refresh_registry};
 use crate::ui_focus::{FocusGroup, FocusRow, Focusable, FocusedButton};
 use crate::ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_button, spawn_modal_header, ButtonVariant,
@@ -34,9 +40,10 @@ use crate::ui_modal::{
 };
 use crate::ui_tooltip::Tooltip;
 use crate::ui_theme::{
-    BG_BASE, BG_ELEVATED, BG_ELEVATED_HI, BORDER_SUBTLE, RADIUS_SM, SPACE_2, STATE_SUCCESS,
+    BG_BASE, BG_ELEVATED, BG_ELEVATED_HI, BORDER_SUBTLE, BORDER_SUBTLE_HC, HighContrastBackground,
-    TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3,
+    HighContrastBorder,
-    Z_MODAL_PANEL,
+    RADIUS_SM, SPACE_2, STATE_SUCCESS, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG,
+    TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3, Z_MODAL_PANEL,
 };
 
 /// Side length of a swatch button in the card-back / background pickers.
@@ -229,7 +236,15 @@ enum SettingsButton {
     /// flag only affects launches without saved geometry — the
     /// player's last window size always wins.
     ToggleSmartDefaultSize,
+    /// Scan `user_theme_dir()` for new `.zip` files and import each one.
+    ScanThemes,
     SyncNow,
+    /// Open the sync-server Connect modal (shown when backend = Local).
+    ConnectSync,
+    /// Disconnect from the sync server (shown when backend = SolitaireServer).
+    DisconnectSync,
+    /// Open the account-deletion confirmation modal.
+    DeleteAccount,
     Done,
     /// Select a specific card-back by index from the picker row.
     SelectCardBack(usize),
@@ -281,8 +296,12 @@ impl SettingsButton {
             SettingsButton::SelectCardBack(_) => 70,
             SettingsButton::SelectBackground(_) => 80,
             SettingsButton::SelectTheme(_) => 85,
+            SettingsButton::ScanThemes => 86,
             // Sync section
             SettingsButton::SyncNow => 90,
+            SettingsButton::ConnectSync => 91,
+            SettingsButton::DisconnectSync => 92,
+            SettingsButton::DeleteAccount => 93,
             // Done is tagged by `attach_focusable_to_modal_buttons` and
             // never reaches `attach_focusable_to_settings_buttons`; the
             // value here is only a fallback for completeness.
@@ -332,6 +351,9 @@ impl Plugin for SettingsPlugin {
             .init_resource::<PendingWindowGeometry>()
             .add_message::<SettingsChangedEvent>()
             .add_message::<ManualSyncRequestEvent>()
+            .add_message::<SyncConfigureRequestEvent>()
+            .add_message::<SyncLogoutRequestEvent>()
+            .add_message::<DeleteAccountRequestEvent>()
             .add_message::<ToggleSettingsRequestEvent>()
             .add_message::<InfoToastEvent>()
             .add_message::<bevy::input::mouse::MouseWheel>()
@@ -358,12 +380,16 @@ impl Plugin for SettingsPlugin {
                 (
                     sync_settings_panel_visibility,
                     handle_settings_buttons,
+                    handle_sync_buttons,
+                    handle_scan_themes,
                     update_sync_status_text,
                     update_card_back_text,
                     update_background_text,
                     update_anim_speed_text,
                     update_color_blind_text,
                     update_high_contrast_text,
+                    update_high_contrast_borders,
+                    update_high_contrast_backgrounds,
                     update_reduce_motion_text,
                     update_tooltip_delay_text,
                     update_time_bonus_multiplier_text,
@@ -637,6 +663,77 @@ fn update_high_contrast_text(
     }
 }
 
+/// Repaints `BorderColor` on every entity tagged with
+/// [`HighContrastBorder`] based on `Settings::high_contrast_mode`.
+/// Off → the marker's `default_color`; on → `BORDER_SUBTLE_HC`
+/// (`#a0a0a0`). Compares against the current border colour and
+/// only mutates when different so Bevy's change-detection
+/// doesn't trigger repaints every frame.
+///
+/// Spec at `design-system.md` §Accessibility (#2): under HC,
+/// outlines boost from `#505050` (BORDER_STRONG) to `#a0a0a0` so
+/// modal panels, popover edges, and focus-ring carriers stay
+/// legible on low-quality displays / for low-vision users.
+///
+/// Tagged sites in v0.21.x: the modal scaffold's card border
+/// (`ui_modal::spawn_modal`). More sites can be tagged in
+/// follow-ups by adding `HighContrastBorder::with_default(...)`
+/// to their spawn tuple.
+fn update_high_contrast_borders(
+    settings: Res<SettingsResource>,
+    mut borders: Query<(&HighContrastBorder, &mut BorderColor)>,
+) {
+    let high_contrast = settings.0.high_contrast_mode;
+    for (marker, mut border) in borders.iter_mut() {
+        let target = if high_contrast {
+            BORDER_SUBTLE_HC
+        } else {
+            marker.default_color
+        };
+        // Only mutate when actually different — avoids per-frame
+        // change-detection churn. `border.left` is representative
+        // because every tagged site uses `BorderColor::all(...)`.
+        if border.left != target {
+            *border = BorderColor::all(target);
+        }
+    }
+}
+
+/// Repaints `BackgroundColor` on every entity tagged with
+/// [`HighContrastBackground`] based on `Settings::high_contrast_mode`.
+/// Off → the marker's `default_color`; on → `BORDER_SUBTLE_HC`
+/// (`#a0a0a0`). Compares against the current background and only
+/// mutates when different so Bevy's change-detection doesn't trigger
+/// repaints every frame.
+///
+/// Parallel to [`update_high_contrast_borders`]. Same on/off rule,
+/// same change-suppression idiom, different colour channel —
+/// `BackgroundColor` for tick marks, decorative strips, fine
+/// separators that paint their shape directly rather than via a
+/// `BorderColor` on a wider Node.
+///
+/// Tagged sites in v0.21.x: the replay overlay's 1 px scrub track
+/// + 5 quarter-mark notch ticks (`replay_overlay::spawn_overlay`).
+///
+/// More sites can be tagged in follow-ups by adding
+/// `HighContrastBackground::with_default(...)` to their spawn tuple.
+pub(crate) fn update_high_contrast_backgrounds(
+    settings: Res<SettingsResource>,
+    mut backgrounds: Query<(&HighContrastBackground, &mut BackgroundColor)>,
+) {
+    let high_contrast = settings.0.high_contrast_mode;
+    for (marker, mut bg) in backgrounds.iter_mut() {
+        let target = if high_contrast {
+            marker.hc_color
+        } else {
+            marker.default_color
+        };
+        if bg.0 != target {
+            *bg = BackgroundColor(target);
+        }
+    }
+}
+
 fn update_reduce_motion_text(
     settings: Res<SettingsResource>,
     mut text_nodes: Query<&mut Text, With<ReduceMotionText>>,
@@ -766,7 +863,6 @@ fn handle_settings_buttons(
     mut screen: ResMut<SettingsScreen>,
     path: Res<SettingsStoragePath>,
     mut changed: MessageWriter<SettingsChangedEvent>,
-    mut manual_sync: MessageWriter<ManualSyncRequestEvent>,
     mut sfx_text: Query<&mut Text, (With<SfxVolumeText>, Without<MusicVolumeText>, Without<DrawModeText>, Without<ThemeText>, Without<AnimSpeedText>, Without<ColorBlindText>, Without<HighContrastText>, Without<ReduceMotionText>)>,
     mut music_text: Query<&mut Text, (With<MusicVolumeText>, Without<SfxVolumeText>, Without<DrawModeText>, Without<ThemeText>, Without<AnimSpeedText>, Without<ColorBlindText>, Without<HighContrastText>, Without<ReduceMotionText>)>,
     mut draw_text: Query<&mut Text, (With<DrawModeText>, Without<SfxVolumeText>, Without<MusicVolumeText>, Without<ThemeText>, Without<AnimSpeedText>, Without<ColorBlindText>, Without<HighContrastText>, Without<ReduceMotionText>)>,
@@ -979,8 +1075,14 @@ fn handle_settings_buttons(
                     changed.write(SettingsChangedEvent(settings.0.clone()));
                 }
             }
-            SettingsButton::SyncNow => {
+            SettingsButton::ScanThemes => {
-                manual_sync.write(ManualSyncRequestEvent);
+                // Handled by `handle_scan_themes`.
+            }
+            SettingsButton::SyncNow
+            | SettingsButton::ConnectSync
+            | SettingsButton::DisconnectSync
+            | SettingsButton::DeleteAccount => {
+                // Handled by `handle_sync_buttons`.
             }
             SettingsButton::Done => {
                 screen.0 = false;
@@ -989,6 +1091,30 @@ fn handle_settings_buttons(
     }
 }
 
+/// Handles sync-related settings buttons: Sync Now, Connect, Disconnect,
+/// and Delete Account. Split from `handle_settings_buttons` to stay within
+/// Bevy's 16-parameter system limit.
+fn handle_sync_buttons(
+    interaction_query: Query<(&Interaction, &SettingsButton), Changed<Interaction>>,
+    mut manual_sync: MessageWriter<ManualSyncRequestEvent>,
+    mut configure_sync: MessageWriter<SyncConfigureRequestEvent>,
+    mut logout_sync: MessageWriter<SyncLogoutRequestEvent>,
+    mut delete_account: MessageWriter<DeleteAccountRequestEvent>,
+) {
+    for (interaction, button) in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        match button {
+            SettingsButton::SyncNow => { manual_sync.write(ManualSyncRequestEvent); }
+            SettingsButton::ConnectSync => { configure_sync.write(SyncConfigureRequestEvent); }
+            SettingsButton::DisconnectSync => { logout_sync.write(SyncLogoutRequestEvent); }
+            SettingsButton::DeleteAccount => { delete_account.write(DeleteAccountRequestEvent); }
+            _ => {}
+        }
+    }
+}
+
 fn draw_mode_label(mode: &DrawMode) -> String {
     match mode {
         DrawMode::DrawOne => "Draw 1".into(),
@@ -1519,10 +1645,11 @@ fn spawn_settings_panel(
                     font_res,
                 );
             }
+            import_themes_row(body, font_res);
 
             // --- Sync ---
             section_label(body, "Sync", font_res);
-            sync_row(body, sync_status, font_res);
+            sync_row(body, sync_status, &settings.sync_backend, font_res);
         });
 
         // Done is the only action — primary so the player always knows
@@ -1913,6 +2040,7 @@ fn picker_row(
                     },
                     BackgroundColor(bg),
                     BorderColor::all(BORDER_SUBTLE),
+                    HighContrastBorder::with_default(BORDER_SUBTLE),
                 ))
                 .with_children(|b| {
                     let text_color = if is_selected { BG_BASE } else { TEXT_PRIMARY };
@@ -2054,6 +2182,7 @@ fn theme_picker_row(
                     },
                     BackgroundColor(bg),
                     BorderColor::all(BORDER_SUBTLE),
+                    HighContrastBorder::with_default(BORDER_SUBTLE),
                 ))
                 .with_children(|b| {
                     spawn_thumbnail_pair(b, entry.thumbnails.as_ref());
@@ -2132,8 +2261,14 @@ fn spawn_thumbnail_placeholder(parent: &mut ChildSpawnerCommands) {
     ));
 }
 
-/// Status text + manual "Sync Now" button.
+/// Sync section row — shows different controls depending on whether a server
-fn sync_row(parent: &mut ChildSpawnerCommands, status_text: &str, font_res: Option<&FontResource>) {
+/// backend is configured.
+fn sync_row(
+    parent: &mut ChildSpawnerCommands,
+    status_text: &str,
+    backend: &SyncBackend,
+    font_res: Option<&FontResource>,
+) {
     let status_font = TextFont {
         font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
         font_size: TYPE_BODY,
@@ -2144,28 +2279,17 @@ fn sync_row(parent: &mut ChildSpawnerCommands, status_text: &str, font_res: Opti
         font_size: TYPE_CAPTION,
         ..default()
     };
-    parent
+
-        .spawn(Node {
+    // Helper closure to spawn a small settings-style pill button.
-            flex_direction: FlexDirection::Row,
+    let small_button = |row: &mut ChildSpawnerCommands,
-            align_items: AlignItems::Center,
+                        marker: SettingsButton,
-            column_gap: VAL_SPACE_3,
+                        label: &str,
-            ..default()
+                        tooltip: String,
-        })
+                        font: TextFont| {
-        .with_children(|row| {
         row.spawn((
-                SyncStatusText,
+            marker,
-                Text::new(status_text.to_string()),
-                status_font,
-                TextColor(TEXT_SECONDARY),
-            ));
-            // ManualSyncRequestEvent is always registered, so this
-            // button is safe to show even when SyncPlugin is absent.
-            row.spawn((
-                SettingsButton::SyncNow,
             Button,
-                Tooltip::new(
+            Tooltip::new(tooltip),
-                    "Push and pull stats now. Runs automatically on launch and exit.",
-                ),
             Node {
                 padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_2),
                 justify_content: JustifyContent::Center,
@@ -2175,14 +2299,86 @@ fn sync_row(parent: &mut ChildSpawnerCommands, status_text: &str, font_res: Opti
             },
             BackgroundColor(BG_ELEVATED_HI),
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
         ))
         .with_children(|b| {
             b.spawn((
-                    Text::new("Sync Now"),
+                Text::new(label.to_string()),
-                    button_font,
+                font,
                 TextColor(TEXT_PRIMARY),
             ));
         });
+    };
+
+    parent
+        .spawn(Node {
+            flex_direction: FlexDirection::Column,
+            row_gap: VAL_SPACE_2,
+            ..default()
+        })
+        .with_children(|col| {
+            // Status line + inline action buttons.
+            col.spawn(Node {
+                flex_direction: FlexDirection::Row,
+                align_items: AlignItems::Center,
+                column_gap: VAL_SPACE_3,
+                flex_wrap: FlexWrap::Wrap,
+                row_gap: VAL_SPACE_2,
+                ..default()
+            })
+            .with_children(|row| {
+                row.spawn((
+                    SyncStatusText,
+                    Text::new(status_text.to_string()),
+                    status_font,
+                    TextColor(TEXT_SECONDARY),
+                ));
+
+                match backend {
+                    SyncBackend::Local => {
+                        small_button(
+                            row,
+                            SettingsButton::ConnectSync,
+                            "Connect",
+                            "Connect to a self-hosted Solitaire Quest sync server.".to_string(),
+                            button_font,
+                        );
+                    }
+                    SyncBackend::SolitaireServer { username, .. } => {
+                        // Show the logged-in username as a secondary label.
+                        row.spawn((
+                            Text::new(format!("({username})")),
+                            TextFont {
+                                font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+                                font_size: TYPE_CAPTION,
+                                ..default()
+                            },
+                            TextColor(TEXT_SECONDARY),
+                        ));
+                        small_button(
+                            row,
+                            SettingsButton::SyncNow,
+                            "Sync Now",
+                            "Push and pull stats now. Runs automatically on launch and exit.".to_string(),
+                            button_font.clone(),
+                        );
+                        small_button(
+                            row,
+                            SettingsButton::DisconnectSync,
+                            "Disconnect",
+                            "Unlink this device from the sync server.".to_string(),
+                            button_font.clone(),
+                        );
+                        small_button(
+                            row,
+                            SettingsButton::DeleteAccount,
+                            "Delete Account",
+                            "Permanently delete your account and all server data. Cannot be undone.".to_string(),
+                            button_font,
+                        );
+                    }
+                }
+            });
         });
 }
 
@@ -2207,6 +2403,172 @@ fn value_text_font(font_res: Option<&FontResource>) -> TextFont {
 /// `tooltip` is the hover-reveal caption attached via [`Tooltip`]. Every
 /// Settings icon button ships with one because the glyph alone (`+`, `−`,
 /// `⇄`) does not name what it adjusts; the tooltip carries that meaning.
+/// Scans `user_theme_dir()` for `.zip` files and calls [`import_theme`] on
+/// each one. On success, [`ThemeRegistry`] is refreshed in place and an
+/// [`InfoToastEvent`] is fired per imported theme. `IdCollision` errors (theme
+/// already installed) are silently skipped; all other errors produce a warning
+/// toast. A final toast tells the player to reopen Settings to see new themes.
+fn handle_scan_themes(
+    interaction_query: Query<(&Interaction, &SettingsButton), Changed<Interaction>>,
+    mut toast: MessageWriter<InfoToastEvent>,
+    mut registry: Option<ResMut<crate::theme::ThemeRegistry>>,
+) {
+    for (interaction, button) in &interaction_query {
+        if *interaction != Interaction::Pressed {
+            continue;
+        }
+        if !matches!(button, SettingsButton::ScanThemes) {
+            continue;
+        }
+
+        let themes_dir = user_theme_dir();
+
+        let zips: Vec<std::path::PathBuf> = match std::fs::read_dir(&themes_dir) {
+            Ok(entries) => entries
+                .flatten()
+                .map(|e| e.path())
+                .filter(|p| p.extension().is_some_and(|ext| ext == "zip"))
+                .collect(),
+            Err(_) => {
+                toast.write(InfoToastEvent(
+                    "Themes folder not found — drop .zip files there first.".to_string(),
+                ));
+                return;
+            }
+        };
+
+        if zips.is_empty() {
+            toast.write(InfoToastEvent(
+                "No .zip files found in themes folder.".to_string(),
+            ));
+            return;
+        }
+
+        let mut imported = 0u32;
+        let mut errors = 0u32;
+
+        for zip_path in &zips {
+            match import_theme(zip_path) {
+                Ok(theme_id) => {
+                    toast.write(InfoToastEvent(format!(
+                        "Imported theme '{}'.",
+                        theme_id.as_str()
+                    )));
+                    imported += 1;
+                }
+                Err(ImportError::IdCollision { .. }) => {
+                    // Already installed — silent skip.
+                }
+                Err(e) => {
+                    let name = zip_path
+                        .file_name()
+                        .map(|n| n.to_string_lossy().into_owned())
+                        .unwrap_or_default();
+                    toast.write(InfoToastEvent(format!("Import failed ({name}): {e}")));
+                    errors += 1;
+                }
+            }
+        }
+
+        if imported == 0 && errors == 0 {
+            toast.write(InfoToastEvent("All themes already installed.".to_string()));
+            return;
+        }
+
+        if imported > 0 {
+            if let Some(reg) = &mut registry {
+                refresh_registry(reg, &themes_dir);
+            }
+            toast.write(InfoToastEvent(
+                "Reopen Settings to see new themes in the picker.".to_string(),
+            ));
+        }
+    }
+}
+
+/// A small pill-shaped settings button, matching the style used in `sync_row`.
+fn pill_button(
+    parent: &mut ChildSpawnerCommands,
+    marker: SettingsButton,
+    label: &str,
+    tooltip: &'static str,
+    font_res: Option<&FontResource>,
+) {
+    let font = TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+    parent
+        .spawn((
+            marker,
+            Button,
+            Tooltip::new(tooltip),
+            Node {
+                padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_2),
+                justify_content: JustifyContent::Center,
+                border: UiRect::all(Val::Px(1.0)),
+                border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                ..default()
+            },
+            BackgroundColor(BG_ELEVATED_HI),
+            BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
+        ))
+        .with_children(|b| {
+            b.spawn((Text::new(label.to_string()), font, TextColor(TEXT_PRIMARY)));
+        });
+}
+
+/// "Import Theme" row: folder-path label + "Scan for new themes" button.
+///
+/// The player drops `.zip` theme archives into the themes folder shown here,
+/// then presses the button. [`handle_scan_themes`] picks them up, validates,
+/// and installs them. Reopen Settings to see newly imported themes in the
+/// card-theme picker.
+fn import_themes_row(parent: &mut ChildSpawnerCommands, font_res: Option<&FontResource>) {
+    let caption_font = TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+
+    parent
+        .spawn((
+            FocusRow,
+            Node {
+                flex_direction: FlexDirection::Column,
+                row_gap: VAL_SPACE_2,
+                ..default()
+            },
+        ))
+        .with_children(|col| {
+            // Folder path hint.
+            let path_str = user_theme_dir().to_string_lossy().into_owned();
+            col.spawn((
+                Text::new(format!("Drop .zip files into: {path_str}")),
+                caption_font,
+                TextColor(TEXT_SECONDARY),
+            ));
+
+            // Scan button.
+            col.spawn(Node {
+                flex_direction: FlexDirection::Row,
+                align_items: AlignItems::Center,
+                ..default()
+            })
+            .with_children(|row| {
+                pill_button(
+                    row,
+                    SettingsButton::ScanThemes,
+                    "Scan for new themes",
+                    "Scan the themes folder for .zip archives and install any that are new.",
+                    font_res,
+                );
+            });
+        });
+}
+
 fn icon_button(
     parent: &mut ChildSpawnerCommands,
     label: &str,
@@ -2235,6 +2597,7 @@ fn icon_button(
             },
             BackgroundColor(BG_ELEVATED_HI),
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
         ))
         .with_children(|b| {
             b.spawn((Text::new(label.to_string()), glyph_font, TextColor(TEXT_PRIMARY)));
@@ -2542,19 +2905,20 @@ mod tests {
             "expected the panel to spawn many tooltipped buttons; got {tipped_count}"
         );
 
-        // Spot-check: the Sync Now button's tooltip text is the
+        // Spot-check: with default (Local) settings the Connect button
-        // canonical microcopy. We find it via the `SettingsButton`
+        // spawns. We verify its tooltip carries the canonical microcopy.
-        // discriminant — there is exactly one Sync Now entity per panel.
+        let connect_tip = app
-        let sync_tip = app
             .world_mut()
             .query::<(&SettingsButton, &Tooltip)>()
             .iter(app.world())
-            .find_map(|(btn, tip)| matches!(btn, SettingsButton::SyncNow).then(|| tip.0.clone()))
+            .find_map(|(btn, tip)| {
-            .expect("Sync Now button should spawn with a Tooltip");
+                matches!(btn, SettingsButton::ConnectSync).then(|| tip.0.clone())
+            })
+            .expect("Connect button should spawn with a Tooltip when backend is Local");
         assert_eq!(
-            sync_tip.as_ref(),
+            connect_tip.as_ref(),
-            "Push and pull stats now. Runs automatically on launch and exit.",
+            "Connect to a self-hosted Solitaire Quest sync server.",
-            "Sync Now tooltip must use the canonical microcopy"
+            "ConnectSync tooltip must use the canonical microcopy"
         );
     }
 

solitaire_engine/src/splash_plugin.rs

@@ -219,12 +219,27 @@ fn spawn_splash(
 
     let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();
 
+    // Settings is borrowed twice — once for the first_run_complete
+    // gate above, once here for the reduce-motion gate. The borrow
+    // above already happened (and was let-go via the `settings.as_deref()`
+    // pattern's auto-drop), so this re-read is safe.
+    let reduce_motion = settings.is_some_and(|s| s.0.reduce_motion_mode);
+
     // Generate the scanline texture handle up-front (when the asset
     // store is available — always true in production; opt-out under
     // bare `MinimalPlugins` test fixtures so existing tests that
     // don't init `Assets<Image>` keep working with the rest of the
-    // splash content unchanged).
+    // splash content unchanged). Also skipped when reduce-motion is
-    let scanline_handle = images.map(|mut images| images.add(build_scanline_image()));
+    // on — the scanline overlay is the "CRT scanline effect" the
+    // design-system spec calls out as non-essential motion under
+    // reduce-motion (`design-system.md` §Accessibility #3). Without
+    // it the boot screen still reads as terminal-themed; the
+    // scanlines are decorative.
+    let scanline_handle = if reduce_motion {
+        None
+    } else {
+        images.map(|mut images| images.add(build_scanline_image()))
+    };
 
     commands
         .spawn((
@@ -712,15 +727,29 @@ fn cursor_pulse_factor(age: Duration, period: f32, min: f32) -> f32 {
 ///
 /// No-op when no `SplashRoot` exists (the splash has already
 /// despawned, or we're under a test fixture that doesn't spawn one).
+///
+/// Under `Settings::reduce_motion_mode`, the per-frame pulse
+/// multiplier is skipped — the cursor still fades in / out with
+/// the global splash alpha (essential timing) but doesn't blink
+/// (decorative motion). Spec at `design-system.md` §Accessibility
+/// (#3): reduce-motion suppresses non-essential motion only;
+/// fade-in / fade-out timelines stay intact because the splash
+/// itself would otherwise hard-cut on/off, which is jarring.
 fn pulse_splash_cursor(
     roots: Query<&SplashAge, With<SplashRoot>>,
+    settings: Option<Res<SettingsResource>>,
     mut pulses: Query<(&SplashFadableBg, &mut BackgroundColor), With<SplashCursorPulse>>,
 ) {
     let Some(age) = roots.iter().next() else {
         return;
     };
     let global = splash_alpha(age.0).unwrap_or(0.0);
-    let pulse = cursor_pulse_factor(age.0, MOTION_PULSE_PERIOD_SECS, PULSE_ALPHA_MIN);
+    let reduce_motion = settings.is_some_and(|s| s.0.reduce_motion_mode);
+    let pulse = if reduce_motion {
+        1.0
+    } else {
+        cursor_pulse_factor(age.0, MOTION_PULSE_PERIOD_SECS, PULSE_ALPHA_MIN)
+    };
     let combined = (global * pulse).clamp(0.0, 1.0);
     for (fadable, mut bg) in &mut pulses {
         let mut c = fadable.base_color;
@@ -954,6 +983,46 @@ mod tests {
         );
     }
 
+    #[test]
+    fn splash_skips_scanline_overlay_under_reduce_motion() {
+        // The CRT scanline overlay is decorative motion that
+        // `Settings::reduce_motion_mode` suppresses per the
+        // design-system spec (§Accessibility #3). The splash
+        // root itself still spawns — the cursor still fades in
+        // and out (essential timing), but the scanline overlay
+        // node is omitted entirely.
+        use solitaire_data::Settings;
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(bevy::asset::AssetPlugin::default())
+            .init_asset::<bevy::image::Image>()
+            .add_plugins(SplashPlugin);
+        app.init_resource::<ButtonInput<KeyCode>>();
+        app.init_resource::<ButtonInput<MouseButton>>();
+        app.insert_resource(SettingsResource(Settings {
+            first_run_complete: false,
+            reduce_motion_mode: true,
+            ..Settings::default()
+        }));
+        app.update();
+        // The splash root spawns (essential motion intact)
+        assert_eq!(
+            count_splash_roots(&mut app),
+            1,
+            "splash should still spawn under reduce-motion — only the scanline + pulse are gated",
+        );
+        // The scanline overlay is gone
+        let scanline_count = app
+            .world_mut()
+            .query::<&SplashScanlineOverlay>()
+            .iter(app.world())
+            .count();
+        assert_eq!(
+            scanline_count, 0,
+            "scanline overlay must NOT spawn under reduce-motion",
+        );
+    }
+
     #[test]
     fn splash_despawns_after_total_duration() {
         let mut app = headless_app();

solitaire_engine/src/stats_plugin.rs

@@ -29,12 +29,13 @@ use crate::resources::GameStateResource;
 use crate::time_attack_plugin::TimeAttackResource;
 use crate::ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_button, spawn_modal_header, ButtonVariant,
-    ScrimDismissible,
+    ModalButton, ScrimDismissible,
 };
 use crate::ui_theme::{
-    ACCENT_PRIMARY, BORDER_SUBTLE, RADIUS_SM, STATE_INFO, STATE_WARNING, STREAK_MILESTONES,
+    ACCENT_PRIMARY, BG_ELEVATED_HI, BORDER_SUBTLE, HighContrastBorder, RADIUS_SM, STATE_INFO,
-    TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_2,
+    STATE_WARNING, STREAK_MILESTONES, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG,
-    VAL_SPACE_3, VAL_SPACE_4, Z_MODAL_PANEL,
+    TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_1, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4,
+    Z_MODAL_PANEL,
 };
 
 /// Bevy resource wrapping the current stats.
@@ -121,6 +122,13 @@ pub struct ReplayNextButton;
 #[derive(Component, Debug)]
 pub struct ReplaySelectorCaption;
 
+/// Marker on the detail text node that shows the selected replay's
+/// `"{duration} win on {date}"` + optional `"· Shareable"` badge.
+/// Repainted by `repaint_replay_selector_detail` whenever the
+/// selection or history changes.
+#[derive(Component, Debug)]
+pub struct ReplaySelectorDetail;
+
 /// Marker component on each per-mode bests row in the stats overlay.
 ///
 /// One row per supported [`solitaire_core::game_state::GameMode`] (Classic,
@@ -223,7 +231,12 @@ impl Plugin for StatsPlugin {
             .add_systems(Update, handle_copy_share_link_button)
             .add_systems(
                 Update,
-                (handle_replay_selector_buttons, repaint_replay_selector_caption).chain(),
+                (
+                    handle_replay_selector_buttons,
+                    repaint_replay_selector_caption,
+                    repaint_replay_selector_detail,
+                )
+                    .chain(),
             )
             .add_systems(Update, scroll_stats_panel);
     }
@@ -348,9 +361,13 @@ fn handle_copy_share_link_button(
     }
     #[cfg(target_os = "android")]
     {
-        toast.write(InfoToastEvent(format!(
+        match crate::android_clipboard::set_text(&url) {
-            "Share link: {url}"
+            Ok(()) => { toast.write(InfoToastEvent(format!("Copied: {url}"))); }
-        )));
+            Err(e) => {
+                warn!("android clipboard failed: {e}");
+                toast.write(InfoToastEvent(format!("Share link: {url}")));
+            }
+        }
     }
 }
 
@@ -439,6 +456,39 @@ fn repaint_replay_selector_caption(
     }
 }
 
+/// Repaints the `ReplaySelectorDetail` text node whenever the
+/// selection or history changes. Shows `"{duration} win on {date}"` for
+/// the selected replay, with a `"· Shareable"` badge when the replay
+/// carries a sync-uploaded share URL. Empty when the history is empty.
+fn repaint_replay_selector_detail(
+    history: Res<ReplayHistoryResource>,
+    selected: Res<SelectedReplayIndex>,
+    mut q: Query<&mut Text, With<ReplaySelectorDetail>>,
+) {
+    if !history.is_changed() && !selected.is_changed() {
+        return;
+    }
+    let label = replay_selector_detail(&history.0.replays, selected.0);
+    for mut text in &mut q {
+        **text = label.clone();
+    }
+}
+
+/// Pure helper: render the detail line for the selected replay. Returns
+/// `"{duration} win on {date}"` plus a `" \u{2022} Shareable"` badge
+/// when a share URL is present. Empty when the history slice is empty.
+pub fn replay_selector_detail(replays: &[solitaire_data::Replay], index: usize) -> String {
+    let Some(r) = replays.get(index.min(replays.len().saturating_sub(1))) else {
+        return String::new();
+    };
+    let base = format_replay_caption(r);
+    if r.share_url.is_some() {
+        format!("{base} \u{2022} Shareable") // ·
+    } else {
+        base
+    }
+}
+
 /// Pure helper: render the selector caption shown next to the Prev /
 /// Next chips. Returns `"No replays"` when the history is empty,
 /// otherwise `"Replay {1-based index} / {total}"`.
@@ -618,14 +668,14 @@ fn toggle_stats_screen(
     if let Ok(entity) = screens.single() {
         commands.entity(entity).despawn();
     } else {
-        let selected = latest_replay.0.replays.get(selected_index.0);
         spawn_stats_screen(
             &mut commands,
             &stats.0,
             progress.as_deref().map(|p| &p.0),
             time_attack.as_deref(),
             font_res.as_deref(),
-            selected,
+            &latest_replay.0.replays,
+            selected_index.0,
         );
     }
 }
@@ -651,7 +701,8 @@ fn spawn_stats_screen(
     progress: Option<&PlayerProgress>,
     time_attack: Option<&TimeAttackResource>,
     font_res: Option<&FontResource>,
-    latest_replay: Option<&Replay>,
+    replays: &[Replay],
+    selected_index: usize,
 ) {
     // --- primary stat cells ---
     // First-launch zero-state: when no games have been played yet, render
@@ -859,31 +910,84 @@ fn spawn_stats_screen(
                     ));
                 }
 
-            // --- Latest replay caption ---
+            // --- Replay selector ---
-            // Surfaces the most recent winning game so the player can spot
+            // Prev / Next chips step through the full replay history;
-            // whether their last victory has been recorded. The Watch
+            // `repaint_replay_selector_caption` and
-            // Replay action below is what the player clicks to revisit it.
+            // `repaint_replay_selector_detail` keep both text nodes
-            //
+            // live as the selection changes. Using `ModalButton` on
-            // When the displayed replay carries a `share_url` (uploaded
+            // the chips plugs them into the existing modal-button
-            // to a sync server, persisted by v0.19.0's share-link
+            // hover/press paint loop at no extra cost.
-            // contract), append a "Shareable" badge so the player can
+            body.spawn(Node {
-            // tell at a glance whether the Copy share link button below
+                flex_direction: FlexDirection::Row,
-            // will produce a URL — without it the button surfaces a
+                align_items: AlignItems::Center,
-            // toast explaining why nothing was copied, which is more
+                column_gap: VAL_SPACE_3,
-            // friction than necessary when a quick visual cue suffices.
+                ..default()
-            let replay_caption = match latest_replay {
+            })
-                Some(r) => {
+            .with_children(|row| {
-                    let base = format!("Latest win: {}", format_replay_caption(r));
+                // ← Prev chip
-                    if r.share_url.is_some() {
+                row.spawn((
-                        format!("{base} \u{2022} Shareable")
+                    ReplayPrevButton,
-                    } else {
+                    ModalButton(ButtonVariant::Secondary),
-                        base
+                    Button,
-                    }
+                    Node {
-                }
+                        padding: UiRect::axes(VAL_SPACE_2, VAL_SPACE_1),
-                None => "No replay recorded yet \u{2014} win a game first.".to_string(),
+                        justify_content: JustifyContent::Center,
-            };
+                        align_items: AlignItems::Center,
+                        border: UiRect::all(Val::Px(1.0)),
+                        border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                        ..default()
+                    },
+                    BackgroundColor(BG_ELEVATED_HI),
+                    BorderColor::all(BORDER_SUBTLE),
+                    HighContrastBorder::with_default(BORDER_SUBTLE),
+                ))
+                .with_children(|b| {
+                    b.spawn((
+                        Text::new("\u{2190}"),
+                        font_row.clone(),
+                        TextColor(TEXT_PRIMARY),
+                    ));
+                });
+
+                // "Replay N / M" caption — rewritten live by
+                // `repaint_replay_selector_caption`.
+                row.spawn((
+                    ReplaySelectorCaption,
+                    Text::new(replay_selector_caption(selected_index, replays.len())),
+                    font_row.clone(),
+                    TextColor(TEXT_SECONDARY),
+                ));
+
+                // → Next chip
+                row.spawn((
+                    ReplayNextButton,
+                    ModalButton(ButtonVariant::Secondary),
+                    Button,
+                    Node {
+                        padding: UiRect::axes(VAL_SPACE_2, VAL_SPACE_1),
+                        justify_content: JustifyContent::Center,
+                        align_items: AlignItems::Center,
+                        border: UiRect::all(Val::Px(1.0)),
+                        border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                        ..default()
+                    },
+                    BackgroundColor(BG_ELEVATED_HI),
+                    BorderColor::all(BORDER_SUBTLE),
+                    HighContrastBorder::with_default(BORDER_SUBTLE),
+                ))
+                .with_children(|b| {
+                    b.spawn((
+                        Text::new("\u{2192}"),
+                        font_row.clone(),
+                        TextColor(TEXT_PRIMARY),
+                    ));
+                });
+            });
+
+            // Detail line: rewritten live by `repaint_replay_selector_detail`.
             body.spawn((
-                Text::new(replay_caption),
+                ReplaySelectorDetail,
+                Text::new(replay_selector_detail(replays, selected_index)),
                 font_row.clone(),
                 TextColor(TEXT_SECONDARY),
             ));
@@ -1017,6 +1121,7 @@ fn spawn_stat_cell(parent: &mut ChildSpawnerCommands, value: &str, label: &str)
                 ..default()
             },
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
         ))
         .with_children(|cell| {
             // Large value label — accent yellow makes the number sing
@@ -1669,6 +1774,140 @@ mod tests {
         );
     }
 
+    // -----------------------------------------------------------------------
+    // Prev/Next replay selector spawn-site tests
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn selector_row_spawns_when_stats_screen_opens() {
+        let mut app = headless_app();
+        // Pre-populate a replay so the selector has something to show.
+        {
+            let mut hist = app.world_mut().resource_mut::<ReplayHistoryResource>();
+            hist.0.replays.push(make_test_replay(90, None));
+        }
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyS);
+        app.update();
+
+        let prev = app
+            .world_mut()
+            .query::<&ReplayPrevButton>()
+            .iter(app.world())
+            .count();
+        let next = app
+            .world_mut()
+            .query::<&ReplayNextButton>()
+            .iter(app.world())
+            .count();
+        let caption = app
+            .world_mut()
+            .query::<&ReplaySelectorCaption>()
+            .iter(app.world())
+            .count();
+        let detail = app
+            .world_mut()
+            .query::<&ReplaySelectorDetail>()
+            .iter(app.world())
+            .count();
+        assert_eq!(prev, 1, "expected one ReplayPrevButton");
+        assert_eq!(next, 1, "expected one ReplayNextButton");
+        assert_eq!(caption, 1, "expected one ReplaySelectorCaption");
+        assert_eq!(detail, 1, "expected one ReplaySelectorDetail");
+    }
+
+    #[test]
+    fn selector_caption_initial_text_is_replay_one_of_one() {
+        let mut app = headless_app();
+        {
+            let mut hist = app.world_mut().resource_mut::<ReplayHistoryResource>();
+            hist.0.replays.push(make_test_replay(120, None));
+        }
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyS);
+        app.update();
+
+        let mut q = app
+            .world_mut()
+            .query_filtered::<&Text, With<ReplaySelectorCaption>>();
+        let texts: Vec<String> = q.iter(app.world()).map(|t| t.0.clone()).collect();
+        assert_eq!(texts.len(), 1);
+        assert_eq!(
+            texts[0],
+            "Replay 1 / 1",
+            "caption must show '1 / 1' for a single-replay history"
+        );
+    }
+
+    #[test]
+    fn selector_detail_initial_text_matches_replay_caption() {
+        let mut app = headless_app();
+        {
+            let mut hist = app.world_mut().resource_mut::<ReplayHistoryResource>();
+            hist.0.replays.push(make_test_replay(65, None)); // 65s → "1:05"
+        }
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyS);
+        app.update();
+
+        let mut q = app
+            .world_mut()
+            .query_filtered::<&Text, With<ReplaySelectorDetail>>();
+        let texts: Vec<String> = q.iter(app.world()).map(|t| t.0.clone()).collect();
+        assert_eq!(texts.len(), 1);
+        assert_eq!(
+            texts[0], "1:05 win on 2026-05-08",
+            "detail must show formatted replay caption for the selected replay"
+        );
+    }
+
+    #[test]
+    fn selector_detail_appends_shareable_badge_when_url_present() {
+        // `replay_selector_detail` is pure — no app setup needed.
+        let replays = vec![make_test_replay(
+            90,
+            Some("https://example.com/r/abc".to_string()),
+        )];
+        let label = replay_selector_detail(&replays, 0);
+        assert!(
+            label.contains("Shareable"),
+            "detail must include 'Shareable' badge when share_url is set, got: {label:?}"
+        );
+    }
+
+    #[test]
+    fn selector_caption_shows_no_replays_when_history_is_empty() {
+        assert_eq!(replay_selector_caption(0, 0), "No replays");
+    }
+
+    #[test]
+    fn selector_caption_wraps_ordinal_correctly() {
+        // index 2 (0-based) in a 3-replay history → "Replay 3 / 3"
+        assert_eq!(replay_selector_caption(2, 3), "Replay 3 / 3");
+    }
+
+    /// Build a minimal [`Replay`] for use in stats-plugin unit tests.
+    ///
+    /// Uses a fixed seed, DrawOne mode, Classic game, 2026-05-08 date.
+    /// `time_seconds` and `share_url` are the only varying fields across tests.
+    fn make_test_replay(time_seconds: u64, share_url: Option<String>) -> solitaire_data::Replay {
+        let date = chrono::NaiveDate::from_ymd_opt(2026, 5, 8).expect("valid date");
+        let mut r = solitaire_data::Replay::new(
+            1,
+            solitaire_core::game_state::DrawMode::DrawOne,
+            solitaire_core::game_state::GameMode::Classic,
+            time_seconds,
+            0,
+            date,
+            vec![],
+        );
+        r.share_url = share_url;
+        r
+    }
+
     /// Integration: pre-set streak to 10, fire a win that bumps it to 11.
     /// Past the highest threshold, no event must fire — the flourish
     /// is reserved for the threshold crossing itself.

solitaire_engine/src/sync_plugin.rs

@@ -25,7 +25,10 @@ use solitaire_data::{
 use solitaire_sync::{merge, SyncPayload, SyncResponse};
 
 use crate::achievement_plugin::{AchievementsResource, AchievementsStoragePath};
-use crate::events::{GameWonEvent, ManualSyncRequestEvent, SyncCompleteEvent};
+use crate::events::{
+    GameWonEvent, InfoToastEvent, ManualSyncRequestEvent, SyncCompleteEvent,
+    SyncConfigureRequestEvent,
+};
 use crate::game_plugin::RecordingReplay;
 use crate::progress_plugin::{ProgressResource, ProgressStoragePath};
 use crate::resources::{GameStateResource, SyncStatus, SyncStatusResource};
@@ -104,6 +107,8 @@ impl Plugin for SyncPlugin {
             .init_resource::<PendingReplayUpload>()
             .add_message::<ManualSyncRequestEvent>()
             .add_message::<SyncCompleteEvent>()
+            .add_message::<SyncConfigureRequestEvent>()
+            .add_message::<InfoToastEvent>()
             .add_systems(Startup, start_pull)
             .add_systems(
                 Update,
@@ -130,7 +135,14 @@ fn start_pull(
 ) {
     let provider = provider.0.clone();
     let task = AsyncComputeTaskPool::get().spawn(async move {
-        provider.pull().await
+        // Bevy's AsyncComputeTaskPool uses async-executor (not Tokio), but
+        // reqwest/hyper require a Tokio reactor for DNS and HTTP I/O. Provide
+        // a short-lived single-threaded runtime for this network round-trip.
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .map_err(|e| SyncError::Network(format!("tokio rt: {e}")))?
+            .block_on(provider.pull())
     });
     task_res.0 = Some(task);
     status.0 = SyncStatus::Syncing;
@@ -153,7 +165,11 @@ fn handle_manual_sync_request(
     }
     let provider = provider.0.clone();
     let task = AsyncComputeTaskPool::get().spawn(async move {
-        provider.pull().await
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .map_err(|e| SyncError::Network(format!("tokio rt: {e}")))?
+            .block_on(provider.pull())
     });
     task_res.0 = Some(task);
     status.0 = SyncStatus::Syncing;
@@ -180,6 +196,8 @@ fn poll_pull_result(
     mut progress: ResMut<ProgressResource>,
     progress_path: Res<ProgressStoragePath>,
     mut complete_writer: MessageWriter<SyncCompleteEvent>,
+    mut configure_sync: MessageWriter<SyncConfigureRequestEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
 ) {
     let Some(task) = task_res.0.as_mut() else {
         return;
@@ -229,10 +247,19 @@ fn poll_pull_result(
             warn!("sync pull failed: {e}");
             let msg = match &e {
                 SyncError::Network(_) => "Can't reach server — check your connection".to_string(),
-                SyncError::Auth(_) => "Login expired — tap Sync Now after re-logging in".to_string(),
+                SyncError::Auth(_) => "Session expired — please reconnect".to_string(),
                 SyncError::Serialization(_) => format!("Unexpected server response: {e}"),
                 SyncError::UnsupportedPlatform => unreachable!("handled above"),
             };
+            // On auth failure, reopen the Connect modal so the player can
+            // re-enter credentials without having to navigate through Settings.
+            // `open_sync_setup_modal` is idempotent — it ignores the event when
+            // the modal is already on screen, so repeated pull failures don't
+            // stack multiple modals.
+            if matches!(e, SyncError::Auth(_)) {
+                toast.write(InfoToastEvent("Session expired — please reconnect".to_string()));
+                configure_sync.write(SyncConfigureRequestEvent);
+            }
             status.0 = SyncStatus::Error(msg.clone());
             complete_writer.write(SyncCompleteEvent(Err(msg)));
         }
@@ -259,11 +286,18 @@ fn push_on_exit(
     let payload = build_payload(&stats.0, &achievements.0, &progress.0);
     let provider = provider.0.clone();
 
-    // Prefer an existing tokio runtime; fall back to futures_lite block_on
+    // Prefer an existing tokio runtime; fall back to a temporary one for
-    // for environments (e.g. tests) that don't have one.
+    // environments (e.g. tests, Android's non-Tokio async executor) where
+    // reqwest/hyper would otherwise panic with "no reactor running".
     let result = match tokio::runtime::Handle::try_current() {
         Ok(handle) => handle.block_on(provider.push(&payload)),
-        Err(_) => future::block_on(provider.push(&payload)),
+        Err(_) => match tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+        {
+            Ok(rt) => rt.block_on(provider.push(&payload)),
+            Err(e) => Err(SyncError::Network(format!("tokio rt on exit: {e}"))),
+        },
     };
     match result {
         Ok(_) => {}
@@ -314,8 +348,13 @@ fn push_replay_on_win(
             recording.moves.clone(),
         );
         let provider = provider.0.clone();
-        let task = AsyncComputeTaskPool::get()
+        let task = AsyncComputeTaskPool::get().spawn(async move {
-            .spawn(async move { provider.push_replay(&replay).await });
+            tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+                .map_err(|e| SyncError::Network(format!("tokio rt: {e}")))?
+                .block_on(provider.push_replay(&replay))
+        });
         // If a previous upload is still in flight, drop it — the most
         // recent win is the one whose share link the player will care
         // about. Bevy's `Task` Drop cancels cooperatively.

solitaire_engine/src/sync_setup_plugin.rs

@@ -0,0 +1,876 @@
+//! Sync-server configuration UI: login / register modal, provider hot-swap,
+//! and disconnect handler.
+//!
+//! # Flow (connect)
+//!
+//! 1. Player clicks "Connect" in the Settings sync section.
+//! 2. `SyncConfigureRequestEvent` → `open_sync_setup_modal` spawns the form.
+//! 3. Player fills URL / Username / Password; Tab cycles fields.
+//! 4. "Log In" or "Register" → `handle_auth_button` → async task on
+//!    `AsyncComputeTaskPool` calling `SolitaireServerClient::login` or
+//!    `::register`.
+//! 5. `poll_auth_task` harvests the result:
+//!    - **Ok**: store tokens → update `SettingsResource` → swap
+//!      `SyncProviderResource` → fire `ManualSyncRequestEvent` → toast + close.
+//!    - **Err**: display error inline; form stays open.
+//!
+//! # Flow (disconnect)
+//!
+//! `SyncLogoutRequestEvent` → `handle_logout` clears tokens, resets
+//! `SyncBackend::Local`, swaps provider, closes settings, shows toast.
+//!
+//! # Flow (delete account)
+//!
+//! 1. Player clicks "Delete Account" in Settings.
+//! 2. `DeleteAccountRequestEvent` → `open_delete_confirm_modal` spawns a
+//!    two-button confirmation modal.
+//! 3. "Cancel" → despawn modal.
+//! 4. "Delete Forever" → `handle_delete_confirm` → async task on
+//!    `AsyncComputeTaskPool` calling `SyncProvider::delete_account`.
+//! 5. `poll_delete_task` harvests the result:
+//!    - **Ok**: fire `SyncLogoutRequestEvent` (clears tokens + resets backend)
+//!      + toast.
+//!    - **Err**: display error in a toast; modal is already closed.
+
+use std::sync::Arc;
+
+use bevy::input::ButtonState;
+use bevy::input::keyboard::KeyboardInput;
+use bevy::prelude::*;
+use bevy::tasks::{futures_lite::future, AsyncComputeTaskPool, Task};
+use solitaire_data::{
+    auth_tokens::{delete_tokens, store_tokens},
+    settings::SyncBackend,
+    save_settings_to,
+    sync_client::{LocalOnlyProvider, SolitaireServerClient},
+    SyncError,
+};
+
+use crate::events::{
+    DeleteAccountRequestEvent, InfoToastEvent, ManualSyncRequestEvent, SyncConfigureRequestEvent,
+    SyncLogoutRequestEvent,
+};
+use crate::font_plugin::FontResource;
+use crate::settings_plugin::{SettingsResource, SettingsScreen, SettingsStoragePath};
+use crate::sync_plugin::SyncProviderResource;
+use crate::ui_modal::spawn_modal;
+use crate::ui_theme::{
+    ACCENT_PRIMARY, BG_ELEVATED, BG_ELEVATED_HI,
+    BORDER_SUBTLE, HighContrastBorder, RADIUS_SM, STATE_DANGER, TEXT_DISABLED,
+    TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3,
+    VAL_SPACE_4, Z_MODAL_PANEL,
+};
+
+// ---------------------------------------------------------------------------
+// Components
+// ---------------------------------------------------------------------------
+
+/// Marker on the sync-setup modal scrim (despawn root).
+#[derive(Component, Debug)]
+pub struct SyncSetupScreen;
+
+/// Discriminant attached to each input-field container and inner text entity.
+#[derive(Component, Clone, Copy, Debug, PartialEq, Eq)]
+enum SyncFieldKind {
+    Url,
+    Username,
+    Password,
+}
+
+/// Per-field raw-text buffer, stored on the inner text entity.
+#[derive(Component, Default, Debug)]
+struct SyncFieldBuffer(String);
+
+/// Marker on the error-message text node.
+#[derive(Component, Debug)]
+struct SyncAuthError;
+
+/// Marks the "Log In" button.
+#[derive(Component, Debug)]
+struct SyncLoginButton;
+
+/// Marks the "Register" button.
+#[derive(Component, Debug)]
+struct SyncRegisterButton;
+
+/// Marks the "Cancel" button.
+#[derive(Component, Debug)]
+struct SyncCancelButton;
+
+/// Marks the spinner / busy overlay node shown while the auth task is running.
+#[derive(Component, Debug)]
+struct SyncBusyOverlay;
+
+// ---------------------------------------------------------------------------
+// Resources
+// ---------------------------------------------------------------------------
+
+/// Which field in the sync-setup modal currently has keyboard focus.
+#[derive(Resource, Default, Clone, Copy, Debug, PartialEq, Eq)]
+enum SyncFocusedField {
+    #[default]
+    Url,
+    Username,
+    Password,
+}
+
+impl SyncFocusedField {
+    fn next(self) -> Self {
+        match self {
+            Self::Url => Self::Username,
+            Self::Username => Self::Password,
+            Self::Password => Self::Url,
+        }
+    }
+
+    fn kind(self) -> SyncFieldKind {
+        match self {
+            Self::Url => SyncFieldKind::Url,
+            Self::Username => SyncFieldKind::Username,
+            Self::Password => SyncFieldKind::Password,
+        }
+    }
+}
+
+/// In-flight login/register task. `url` and `username` are preserved so the
+/// poll system can update settings and provider on success without re-reading
+/// the (already-despawned or cleared) form fields.
+#[derive(Resource, Default)]
+struct PendingAuthTask {
+    task: Option<Task<Result<(String, String), SyncError>>>,
+    url: String,
+    username: String,
+}
+
+/// Marker on the account-deletion confirmation modal root.
+#[derive(Component, Debug)]
+struct DeleteConfirmScreen;
+
+/// Marks the "Delete Forever" confirmation button.
+#[derive(Component, Debug)]
+struct DeleteConfirmButton;
+
+/// Marks the cancel button inside the delete-confirm modal.
+#[derive(Component, Debug)]
+struct DeleteCancelButton;
+
+/// In-flight account-deletion task.
+#[derive(Resource, Default)]
+struct PendingDeleteTask(Option<Task<Result<(), SyncError>>>);
+
+// ---------------------------------------------------------------------------
+// Plugin
+// ---------------------------------------------------------------------------
+
+/// Registers the sync configuration UI systems and resources.
+pub struct SyncSetupPlugin;
+
+impl Plugin for SyncSetupPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<SyncFocusedField>()
+            .init_resource::<PendingAuthTask>()
+            .init_resource::<PendingDeleteTask>()
+            .add_message::<SyncConfigureRequestEvent>()
+            .add_message::<SyncLogoutRequestEvent>()
+            .add_message::<DeleteAccountRequestEvent>()
+            .add_message::<ManualSyncRequestEvent>()
+            .add_message::<InfoToastEvent>()
+            .add_systems(
+                Update,
+                (
+                    open_sync_setup_modal,
+                    handle_text_input,
+                    update_field_borders,
+                    handle_auth_button,
+                    poll_auth_task,
+                    handle_cancel,
+                    handle_logout,
+                    open_delete_confirm_modal,
+                    handle_delete_cancel,
+                    handle_delete_confirm,
+                    poll_delete_task,
+                )
+                    .chain(),
+            );
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Systems
+// ---------------------------------------------------------------------------
+
+/// Opens the sync-setup modal when `SyncConfigureRequestEvent` is received.
+fn open_sync_setup_modal(
+    mut events: MessageReader<SyncConfigureRequestEvent>,
+    existing: Query<(), With<SyncSetupScreen>>,
+    mut commands: Commands,
+    mut focused: ResMut<SyncFocusedField>,
+    font_res: Option<Res<FontResource>>,
+) {
+    if events.is_empty() {
+        return;
+    }
+    events.clear();
+    if !existing.is_empty() {
+        return; // Already open.
+    }
+    *focused = SyncFocusedField::Url;
+    spawn_sync_setup_modal(&mut commands, font_res.as_deref());
+}
+
+/// Routes keyboard input to the focused field while the modal is open.
+fn handle_text_input(
+    screen: Query<(), With<SyncSetupScreen>>,
+    mut key_events: MessageReader<KeyboardInput>,
+    mut focused: ResMut<SyncFocusedField>,
+    mut fields: Query<(&SyncFieldKind, &mut SyncFieldBuffer, &mut Text, &mut TextColor)>,
+    pending: Res<PendingAuthTask>,
+) {
+    if screen.is_empty() || pending.task.is_some() {
+        // Swallow events while modal is closed or auth is in flight.
+        key_events.clear();
+        return;
+    }
+
+    for ev in key_events.read() {
+        if ev.state != ButtonState::Pressed {
+            continue;
+        }
+
+        // Tab / Shift-Tab cycle focus.
+        if ev.key_code == KeyCode::Tab {
+            let shift = ev.logical_key == bevy::input::keyboard::Key::Tab; // no-shift
+            let _ = shift; // handled below via modifier check
+            // Bevy doesn't give us the shift modifier state on KeyboardInput directly,
+            // so we check key_code == Tab and trust that shift produces a separate event.
+            // Use ButtonInput<KeyCode> alternative: we check Tab key here and rely on
+            // the SyncFocusedField cycling being called per press.
+            *focused = focused.next();
+            continue;
+        }
+
+        if ev.key_code == KeyCode::Backspace {
+            for (kind, mut buf, mut text, _) in &mut fields {
+                if *kind == focused.kind() {
+                    buf.0.pop();
+                    text.0 = display_text(&buf.0, *kind);
+                }
+            }
+            continue;
+        }
+
+        // Printable character — append to focused buffer.
+        if let Some(ch) = ev.text.as_deref().and_then(printable_char) {
+            for (kind, mut buf, mut text, mut color) in &mut fields {
+                if *kind == focused.kind() {
+                    if buf.0.len() < 256 {
+                        buf.0.push(ch);
+                    }
+                    text.0 = display_text(&buf.0, *kind);
+                    color.0 = TEXT_PRIMARY;
+                }
+            }
+        }
+    }
+}
+
+/// Updates the border colour of each input field based on which field is focused.
+fn update_field_borders(
+    screen: Query<(), With<SyncSetupScreen>>,
+    focused: Res<SyncFocusedField>,
+    mut borders: Query<(&SyncFieldKind, &mut BorderColor), Without<SyncFieldBuffer>>,
+) {
+    if screen.is_empty() || !focused.is_changed() {
+        return;
+    }
+    for (kind, mut border) in &mut borders {
+        *border = BorderColor::all(if *kind == focused.kind() {
+            ACCENT_PRIMARY
+        } else {
+            BORDER_SUBTLE
+        });
+    }
+}
+
+/// Fires an async auth task when Login or Register is clicked.
+fn handle_auth_button(
+    login_q: Query<&Interaction, (Changed<Interaction>, With<SyncLoginButton>)>,
+    register_q: Query<&Interaction, (Changed<Interaction>, With<SyncRegisterButton>)>,
+    fields: Query<(&SyncFieldKind, &SyncFieldBuffer)>,
+    mut pending: ResMut<PendingAuthTask>,
+    mut error_nodes: Query<(&mut Text, &mut TextColor), With<SyncAuthError>>,
+    mut busy_nodes: Query<&mut Visibility, With<SyncBusyOverlay>>,
+) {
+    let login_clicked = login_q
+        .iter()
+        .any(|i| *i == Interaction::Pressed);
+    let register_clicked = register_q
+        .iter()
+        .any(|i| *i == Interaction::Pressed);
+
+    if !login_clicked && !register_clicked {
+        return;
+    }
+    if pending.task.is_some() {
+        return; // Already in flight.
+    }
+
+    // Collect field values.
+    let mut url = String::new();
+    let mut username = String::new();
+    let mut password = String::new();
+    for (kind, buf) in &fields {
+        match kind {
+            SyncFieldKind::Url => url = buf.0.trim().to_string(),
+            SyncFieldKind::Username => username = buf.0.trim().to_string(),
+            SyncFieldKind::Password => password = buf.0.clone(),
+        }
+    }
+
+    // Basic validation before hitting the network.
+    let validation_error = if url.is_empty() {
+        Some("Server URL is required")
+    } else if !url.starts_with("http://") && !url.starts_with("https://") {
+        Some("URL must start with http:// or https://")
+    } else if username.is_empty() {
+        Some("Username is required")
+    } else if password.is_empty() {
+        Some("Password is required")
+    } else {
+        None
+    };
+
+    if let Some(msg) = validation_error {
+        for (mut text, mut color) in &mut error_nodes {
+            text.0 = msg.to_string();
+            color.0 = STATE_DANGER;
+        }
+        return;
+    }
+
+    // Clear error and show busy indicator.
+    for (mut text, _) in &mut error_nodes {
+        text.0 = "Connecting…".to_string();
+    }
+    for mut vis in &mut busy_nodes {
+        *vis = Visibility::Visible;
+    }
+
+    let is_register = register_clicked;
+    let client = SolitaireServerClient::new(url.clone(), username.clone());
+    let pw = password.clone();
+
+    let task = AsyncComputeTaskPool::get().spawn(async move {
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .map_err(|e| SyncError::Network(format!("tokio rt: {e}")))?
+            .block_on(async {
+                if is_register {
+                    client.register(&pw).await
+                } else {
+                    client.login(&pw).await
+                }
+            })
+    });
+
+    pending.task = Some(task);
+    pending.url = url;
+    pending.username = username;
+}
+
+/// Polls the in-flight auth task. On success updates settings + provider.
+#[allow(clippy::too_many_arguments)]
+fn poll_auth_task(
+    mut pending: ResMut<PendingAuthTask>,
+    mut settings: ResMut<SettingsResource>,
+    settings_path: Res<SettingsStoragePath>,
+    mut provider: ResMut<SyncProviderResource>,
+    mut error_nodes: Query<(&mut Text, &mut TextColor), With<SyncAuthError>>,
+    mut busy_nodes: Query<&mut Visibility, With<SyncBusyOverlay>>,
+    screen: Query<Entity, With<SyncSetupScreen>>,
+    mut settings_screen: ResMut<SettingsScreen>,
+    mut commands: Commands,
+    mut manual_sync: MessageWriter<ManualSyncRequestEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    let Some(task) = pending.task.as_mut() else {
+        return;
+    };
+    let Some(result) = future::block_on(future::poll_once(task)) else {
+        return;
+    };
+    pending.task = None;
+
+    for mut vis in &mut busy_nodes {
+        *vis = Visibility::Hidden;
+    }
+
+    match result {
+        Ok((access_token, refresh_token)) => {
+            let url = pending.url.clone();
+            let username = pending.username.clone();
+
+            // Persist tokens to the OS keychain / Android Keystore.
+            if let Err(e) = store_tokens(&username, &access_token, &refresh_token) {
+                for (mut text, mut color) in &mut error_nodes {
+                    text.0 = format!("Token storage failed: {e}");
+                    color.0 = STATE_DANGER;
+                }
+                return;
+            }
+
+            // Update settings and persist.
+            settings.0.sync_backend = SyncBackend::SolitaireServer {
+                url: url.clone(),
+                username: username.clone(),
+            };
+            if let Some(path) = &settings_path.0
+                && let Err(e) = save_settings_to(path, &settings.0)
+            {
+                warn!("sync setup: failed to persist settings: {e}");
+            }
+
+            // Hot-swap the provider so pull/push use the new credentials.
+            provider.0 = Arc::new(SolitaireServerClient::new(url, username.clone()));
+
+            // Kick off an immediate pull with the new provider.
+            manual_sync.write(ManualSyncRequestEvent);
+
+            // Close both the setup modal and the settings panel.
+            for entity in &screen {
+                commands.entity(entity).despawn();
+            }
+            settings_screen.0 = false;
+
+            toast.write(InfoToastEvent(format!("Connected as {username}")));
+        }
+        Err(e) => {
+            let msg = match e {
+                SyncError::Auth(m) => m,
+                SyncError::Network(m) => format!("Network error: {m}"),
+                SyncError::Serialization(m) => format!("Unexpected response: {m}"),
+                SyncError::UnsupportedPlatform => "Unsupported platform".into(),
+            };
+            for (mut text, mut color) in &mut error_nodes {
+                text.0 = msg.clone();
+                color.0 = STATE_DANGER;
+            }
+        }
+    }
+}
+
+/// Dismisses the sync-setup modal on Cancel click or Escape.
+fn handle_cancel(
+    cancel_q: Query<&Interaction, (Changed<Interaction>, With<SyncCancelButton>)>,
+    keys: Res<ButtonInput<KeyCode>>,
+    screen: Query<Entity, With<SyncSetupScreen>>,
+    mut commands: Commands,
+) {
+    let cancelled = cancel_q.iter().any(|i| *i == Interaction::Pressed)
+        || keys.just_pressed(KeyCode::Escape);
+    if !cancelled || screen.is_empty() {
+        return;
+    }
+    for entity in &screen {
+        commands.entity(entity).despawn();
+    }
+}
+
+/// Clears stored tokens, resets the backend to `Local`, and hot-swaps the
+/// provider. Triggered by "Disconnect" in the settings sync section.
+fn handle_logout(
+    mut events: MessageReader<SyncLogoutRequestEvent>,
+    mut settings: ResMut<SettingsResource>,
+    settings_path: Res<SettingsStoragePath>,
+    mut provider: ResMut<SyncProviderResource>,
+    mut settings_screen: ResMut<SettingsScreen>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    if events.is_empty() {
+        return;
+    }
+    events.clear();
+
+    // Extract username before resetting so we can clear the right keychain key.
+    let username = match &settings.0.sync_backend {
+        SyncBackend::SolitaireServer { username, .. } => Some(username.clone()),
+        SyncBackend::Local => None,
+    };
+
+    if let Some(u) = username
+        && let Err(e) = delete_tokens(&u)
+    {
+        warn!("sync logout: failed to clear tokens: {e}");
+    }
+
+    settings.0.sync_backend = SyncBackend::Local;
+    if let Some(path) = &settings_path.0
+        && let Err(e) = save_settings_to(path, &settings.0)
+    {
+        warn!("sync logout: failed to persist settings: {e}");
+    }
+
+    provider.0 = Arc::new(LocalOnlyProvider);
+    settings_screen.0 = false;
+    toast.write(InfoToastEvent("Disconnected from sync server".to_string()));
+}
+
+/// Opens the account-deletion confirmation modal when `DeleteAccountRequestEvent` fires.
+fn open_delete_confirm_modal(
+    mut events: MessageReader<DeleteAccountRequestEvent>,
+    existing: Query<(), With<DeleteConfirmScreen>>,
+    mut commands: Commands,
+    font_res: Option<Res<FontResource>>,
+) {
+    if events.is_empty() {
+        return;
+    }
+    events.clear();
+    if !existing.is_empty() {
+        return;
+    }
+    spawn_delete_confirm_modal(&mut commands, font_res.as_deref());
+}
+
+/// Despawns the delete-confirm modal on the cancel button or Escape.
+fn handle_delete_cancel(
+    cancel_q: Query<&Interaction, (Changed<Interaction>, With<DeleteCancelButton>)>,
+    keys: Res<ButtonInput<KeyCode>>,
+    screen: Query<Entity, With<DeleteConfirmScreen>>,
+    mut commands: Commands,
+) {
+    let cancelled = cancel_q.iter().any(|i| *i == Interaction::Pressed)
+        || keys.just_pressed(KeyCode::Escape);
+    if !cancelled || screen.is_empty() {
+        return;
+    }
+    for entity in &screen {
+        commands.entity(entity).despawn();
+    }
+}
+
+/// Spawns the async delete-account task when "Delete Forever" is clicked.
+fn handle_delete_confirm(
+    confirm_q: Query<&Interaction, (Changed<Interaction>, With<DeleteConfirmButton>)>,
+    provider: Res<SyncProviderResource>,
+    mut pending: ResMut<PendingDeleteTask>,
+    screen: Query<Entity, With<DeleteConfirmScreen>>,
+    mut commands: Commands,
+) {
+    if !confirm_q.iter().any(|i| *i == Interaction::Pressed) || pending.0.is_some() {
+        return;
+    }
+    // Despawn the confirmation modal immediately so the player can't double-click.
+    for entity in &screen {
+        commands.entity(entity).despawn();
+    }
+    let provider = provider.0.clone();
+    pending.0 = Some(AsyncComputeTaskPool::get().spawn(async move {
+        tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .map_err(|e| SyncError::Network(format!("tokio rt: {e}")))?
+            .block_on(provider.delete_account())
+    }));
+}
+
+/// Polls the in-flight delete-account task. On success fires `SyncLogoutRequestEvent`.
+fn poll_delete_task(
+    mut pending: ResMut<PendingDeleteTask>,
+    mut logout: MessageWriter<SyncLogoutRequestEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    let Some(task) = pending.0.as_mut() else {
+        return;
+    };
+    let Some(result) = future::block_on(future::poll_once(task)) else {
+        return;
+    };
+    pending.0 = None;
+    match result {
+        Ok(()) => {
+            logout.write(SyncLogoutRequestEvent);
+            toast.write(InfoToastEvent("Account deleted".to_string()));
+        }
+        Err(e) => {
+            let msg = match e {
+                SyncError::Auth(_) => "Not authorised — try reconnecting first".to_string(),
+                SyncError::Network(m) => format!("Network error: {m}"),
+                other => format!("Delete failed: {other}"),
+            };
+            toast.write(InfoToastEvent(msg));
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// UI construction
+// ---------------------------------------------------------------------------
+
+fn spawn_sync_setup_modal(commands: &mut Commands, font_res: Option<&FontResource>) {
+    spawn_modal(commands, SyncSetupScreen, Z_MODAL_PANEL + 1, |card| {
+        // Header.
+        card.spawn(Node {
+            padding: UiRect::new(VAL_SPACE_4, VAL_SPACE_4, VAL_SPACE_3, VAL_SPACE_2),
+            ..default()
+        })
+        .with_children(|h| {
+            h.spawn((
+                Text::new("Connect to Server"),
+                make_font(font_res, TYPE_BODY_LG),
+                TextColor(TEXT_PRIMARY),
+            ));
+        });
+
+        // Scrollable body — three labeled input fields + error line.
+        card.spawn(Node {
+            flex_direction: FlexDirection::Column,
+            row_gap: VAL_SPACE_3,
+            padding: UiRect::axes(VAL_SPACE_4, VAL_SPACE_2),
+            flex_grow: 1.0,
+            ..default()
+        })
+        .with_children(|body| {
+            spawn_field(
+                body,
+                SyncFieldKind::Url,
+                "Server URL",
+                "https://your-server.example.com",
+                true,   // focused initially
+                font_res,
+            );
+            spawn_field(
+                body,
+                SyncFieldKind::Username,
+                "Username",
+                "your-username",
+                false,
+                font_res,
+            );
+            spawn_field(
+                body,
+                SyncFieldKind::Password,
+                "Password",
+                "••••••••",
+                false,
+                font_res,
+            );
+
+            // Error / status line.
+            body.spawn(Node {
+                min_height: Val::Px(18.0),
+                ..default()
+            })
+            .with_children(|row| {
+                row.spawn((
+                    SyncAuthError,
+                    SyncBusyOverlay,
+                    Text::new(String::new()),
+                    make_font(font_res, TYPE_CAPTION),
+                    TextColor(TEXT_SECONDARY),
+                    Visibility::Hidden,
+                ));
+            });
+
+            // Tab hint.
+            body.spawn((
+                Text::new("Tab  =  next field"),
+                make_font(font_res, TYPE_CAPTION),
+                TextColor(TEXT_DISABLED),
+            ));
+        });
+
+        // Action row.
+        card.spawn(Node {
+            flex_direction: FlexDirection::Row,
+            justify_content: JustifyContent::FlexEnd,
+            column_gap: VAL_SPACE_2,
+            padding: UiRect::new(VAL_SPACE_4, VAL_SPACE_4, VAL_SPACE_2, VAL_SPACE_3),
+            ..default()
+        })
+        .with_children(|actions| {
+            spawn_action_button(actions, SyncCancelButton, "Cancel", false, font_res);
+            spawn_action_button(actions, SyncRegisterButton, "Register", false, font_res);
+            spawn_action_button(actions, SyncLoginButton, "Log In", true, font_res);
+        });
+    });
+}
+
+fn spawn_field(
+    parent: &mut ChildSpawnerCommands,
+    kind: SyncFieldKind,
+    label: &str,
+    placeholder: &str,
+    focused: bool,
+    font_res: Option<&FontResource>,
+) {
+    parent
+        .spawn(Node {
+            flex_direction: FlexDirection::Column,
+            row_gap: Val::Px(4.0),
+            ..default()
+        })
+        .with_children(|col| {
+            // Label.
+            col.spawn((
+                Text::new(label.to_string()),
+                make_font(font_res, TYPE_CAPTION),
+                TextColor(TEXT_SECONDARY),
+            ));
+
+            // Input border container — carries kind for the border-update system.
+            col.spawn((
+                kind,
+                Node {
+                    border: UiRect::all(Val::Px(1.0)),
+                    border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                    padding: UiRect::axes(VAL_SPACE_2, Val::Px(6.0)),
+                    min_height: Val::Px(32.0),
+                    ..default()
+                },
+                BackgroundColor(BG_ELEVATED),
+                BorderColor::all(if focused { ACCENT_PRIMARY } else { BORDER_SUBTLE }),
+                HighContrastBorder::with_default(BORDER_SUBTLE),
+            ))
+            .with_children(|border| {
+                // Inner text / buffer entity.
+                border.spawn((
+                    kind,
+                    SyncFieldBuffer(String::new()),
+                    Text::new(placeholder.to_string()),
+                    make_font(font_res, TYPE_BODY),
+                    TextColor(TEXT_DISABLED),
+                ));
+            });
+        });
+}
+
+fn spawn_action_button<M: Component>(
+    parent: &mut ChildSpawnerCommands,
+    marker: M,
+    label: &str,
+    primary: bool,
+    font_res: Option<&FontResource>,
+) {
+    let bg = if primary { ACCENT_PRIMARY } else { BG_ELEVATED_HI };
+    let fg = TEXT_PRIMARY;
+    parent
+        .spawn((
+            marker,
+            Button,
+            Node {
+                padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_2),
+                justify_content: JustifyContent::Center,
+                border: UiRect::all(Val::Px(1.0)),
+                border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                ..default()
+            },
+            BackgroundColor(bg),
+            BorderColor::all(if primary { ACCENT_PRIMARY } else { BORDER_SUBTLE }),
+        ))
+        .with_children(|b| {
+            b.spawn((
+                Text::new(label.to_string()),
+                make_font(font_res, TYPE_BODY),
+                TextColor(fg),
+            ));
+        });
+}
+
+// ---------------------------------------------------------------------------
+// Helpers
+// ---------------------------------------------------------------------------
+
+fn make_font(font_res: Option<&FontResource>, size: f32) -> TextFont {
+    TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: size,
+        ..default()
+    }
+}
+
+fn spawn_delete_confirm_modal(commands: &mut Commands, font_res: Option<&FontResource>) {
+    spawn_modal(commands, DeleteConfirmScreen, Z_MODAL_PANEL + 2, |card| {
+        // Header.
+        card.spawn(Node {
+            padding: UiRect::new(VAL_SPACE_4, VAL_SPACE_4, VAL_SPACE_3, VAL_SPACE_2),
+            ..default()
+        })
+        .with_children(|h| {
+            h.spawn((
+                Text::new("Delete Account"),
+                make_font(font_res, TYPE_BODY_LG),
+                TextColor(STATE_DANGER),
+            ));
+        });
+
+        // Body.
+        card.spawn(Node {
+            flex_direction: FlexDirection::Column,
+            row_gap: VAL_SPACE_2,
+            padding: UiRect::axes(VAL_SPACE_4, VAL_SPACE_2),
+            ..default()
+        })
+        .with_children(|body| {
+            body.spawn((
+                Text::new(
+                    "This permanently deletes your account and all server data.\n\
+                     Local progress is kept. This cannot be undone.",
+                ),
+                make_font(font_res, TYPE_BODY),
+                TextColor(TEXT_SECONDARY),
+            ));
+        });
+
+        // Actions.
+        card.spawn(Node {
+            flex_direction: FlexDirection::Row,
+            justify_content: JustifyContent::FlexEnd,
+            column_gap: VAL_SPACE_2,
+            padding: UiRect::new(VAL_SPACE_4, VAL_SPACE_4, VAL_SPACE_2, VAL_SPACE_3),
+            ..default()
+        })
+        .with_children(|actions| {
+            spawn_action_button(actions, DeleteCancelButton, "Cancel", false, font_res);
+            // "Delete Forever" button — danger styling (STATE_DANGER background).
+            actions
+                .spawn((
+                    DeleteConfirmButton,
+                    Button,
+                    Node {
+                        padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_2),
+                        justify_content: JustifyContent::Center,
+                        border: UiRect::all(Val::Px(1.0)),
+                        border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+                        ..default()
+                    },
+                    BackgroundColor(STATE_DANGER),
+                    BorderColor::all(STATE_DANGER),
+                ))
+                .with_children(|b| {
+                    b.spawn((
+                        Text::new("Delete Forever"),
+                        make_font(font_res, TYPE_BODY),
+                        TextColor(TEXT_PRIMARY),
+                    ));
+                });
+        });
+    });
+}
+
+/// Returns the display string for a field — password fields show bullets.
+fn display_text(raw: &str, kind: SyncFieldKind) -> String {
+    if kind == SyncFieldKind::Password {
+        "•".repeat(raw.len())
+    } else {
+        raw.to_string()
+    }
+}
+
+/// Extracts a printable ASCII character from a SmolStr keypress text.
+fn printable_char(text: &str) -> Option<char> {
+    let ch = text.chars().next()?;
+    // Accept printable ASCII: 0x20 (space) through 0x7e (~).
+    (' '..='~').contains(&ch).then_some(ch)
+}

solitaire_engine/src/table_plugin.rs

@@ -11,6 +11,7 @@ use solitaire_core::pile::PileType;
 
 use crate::events::{HintVisualEvent, StateChangedEvent};
 use crate::layout::{compute_layout, Layout, LayoutResource, LayoutSystem};
+use crate::safe_area::SafeAreaInsets;
 use crate::resources::GameStateResource;
 #[cfg(test)]
 use crate::layout::TABLE_COLOUR;
@@ -82,6 +83,7 @@ impl Plugin for TablePlugin {
             .add_systems(
                 Update,
                 (
+                    on_safe_area_changed.before(LayoutSystem::UpdateOnResize),
                     on_window_resized.in_set(LayoutSystem::UpdateOnResize),
                     apply_theme_on_settings_change,
                     apply_hint_pile_highlight,
@@ -146,18 +148,38 @@ fn setup_table(
     existing_camera: Query<(), With<Camera>>,
     settings: Option<Res<SettingsResource>>,
     bg_images: Option<Res<BackgroundImageSet>>,
+    safe_area: Option<Res<SafeAreaInsets>>,
 ) {
     // Only spawn a camera if one does not already exist (e.g. a parent app
-    // may have added one in tests).
+    // may have added one in tests). Use the felt-green clear colour so the
+    // background reads as green even before the background PNG finishes
+    // loading (which is asynchronous and can lag by several frames on
+    // Android).
     if existing_camera.is_empty() {
-        commands.spawn(Camera2d);
+        commands.spawn((
+            Camera2d,
+            Camera {
+                clear_color: ClearColorConfig::Custom(Color::srgb(
+                    crate::layout::TABLE_COLOUR[0],
+                    crate::layout::TABLE_COLOUR[1],
+                    crate::layout::TABLE_COLOUR[2],
+                )),
+                ..default()
+            },
+        ));
     }
 
-    let window_size = windows
+    let (window_size, scale) = windows.iter().next().map_or(
-        .iter()
+        (Vec2::new(1280.0, 800.0), 1.0f32),
-        .next()
+        |w| (default_window_size(w), w.scale_factor()),
-        .map_or(Vec2::new(1280.0, 800.0), default_window_size);
+    );
-    let layout = compute_layout(window_size);
+    // Safe-area insets arrive from JNI asynchronously; they are almost always
+    // 0 here (populated ~frame 2-3). on_safe_area_changed fires when they
+    // arrive and issues a synthetic WindowResized to re-snap all game objects.
+    let insets = safe_area.as_deref().copied().unwrap_or_default();
+    let safe_area_top = insets.top / scale;
+    let safe_area_bottom = insets.bottom / scale;
+    let layout = compute_layout(window_size, safe_area_top, safe_area_bottom);
 
     let selected_bg = settings.as_ref().map_or(0, |s| s.0.selected_background);
 
@@ -258,12 +280,11 @@ fn spawn_pile_markers(commands: &mut Commands, layout: &Layout) {
             PileMarker(pile.clone()),
         ));
 
-        // Foundation slots no longer carry a suit letter — any Ace can claim
+        // Tableau markers show "K" (only a King may start an empty column).
-        // any empty slot, so a fixed C/D/H/S badge would be misleading. Empty
+        // Foundation markers show "A" (only an Ace may claim an empty slot).
-        // foundation markers render as plain translucent rectangles.
+        // Neither label carries a suit because any suit may start any slot.
-
+        match &pile {
-        // Task #43 — King indicator on empty tableau placeholders.
+            PileType::Tableau(_) => {
-        if let PileType::Tableau(_) = &pile {
                 entity.with_children(|b| {
                     b.spawn((
                         Text2d::new("K"),
@@ -273,12 +294,26 @@ fn spawn_pile_markers(commands: &mut Commands, layout: &Layout) {
                     ));
                 });
             }
+            PileType::Foundation(_) => {
+                entity.with_children(|b| {
+                    b.spawn((
+                        Text2d::new("A"),
+                        TextFont { font_size, ..default() },
+                        TextColor(TEXT_PRIMARY.with_alpha(0.35)),
+                        Transform::from_xyz(0.0, 0.0, 0.1),
+                    ));
+                });
+            }
+            _ => {}
+        }
     }
 }
 
 #[allow(clippy::type_complexity)]
 fn on_window_resized(
     mut events: MessageReader<WindowResized>,
+    safe_area: Option<Res<SafeAreaInsets>>,
+    windows: Query<&Window>,
     mut layout_res: Option<ResMut<LayoutResource>>,
     mut backgrounds: Query<
         (&mut Sprite, &mut Transform),
@@ -290,7 +325,11 @@ fn on_window_resized(
         return;
     };
     let window_size = Vec2::new(ev.width, ev.height);
-    let new_layout = compute_layout(window_size);
+    let scale = windows.iter().next().map_or(1.0, |w| w.scale_factor());
+    let insets = safe_area.as_deref().copied().unwrap_or_default();
+    let safe_area_top = insets.top / scale;
+    let safe_area_bottom = insets.bottom / scale;
+    let new_layout = compute_layout(window_size, safe_area_top, safe_area_bottom);
 
     if let Some(layout_res) = layout_res.as_deref_mut() {
         layout_res.0 = new_layout.clone();
@@ -318,6 +357,33 @@ fn on_window_resized(
     // and forth" jitter).
 }
 
+/// Bridges the asynchronous safe-area inset update into the synchronous
+/// window-resize pipeline. When Android's JNI delivers the real inset values
+/// (typically frame 2-3 of a fresh launch), this system writes a synthetic
+/// `WindowResized` event carrying the current window size. `on_window_resized`
+/// (which runs in `LayoutSystem::UpdateOnResize`) will then recompute the
+/// layout with the correct `safe_area_top`, update `LayoutResource` and the
+/// pile markers, and `snap_cards_on_window_resize` (running after the set)
+/// will snap card sprites to the corrected positions.
+fn on_safe_area_changed(
+    safe_area: Option<Res<SafeAreaInsets>>,
+    windows: Query<(Entity, &Window)>,
+    mut resize_events: MessageWriter<WindowResized>,
+) {
+    let Some(safe_area) = safe_area else { return; };
+    if !safe_area.is_changed() {
+        return;
+    }
+    let Some((entity, window)) = windows.iter().next() else {
+        return;
+    };
+    resize_events.write(WindowResized {
+        window: entity,
+        width: window.resolution.width(),
+        height: window.resolution.height(),
+    });
+}
+
 // ---------------------------------------------------------------------------
 // Task #6 — Hint pile-marker highlight
 // ---------------------------------------------------------------------------

solitaire_engine/src/ui_modal.rs

@@ -58,8 +58,9 @@ use crate::settings_plugin::SettingsResource;
 use crate::ui_theme::{
     scaled_duration, ACCENT_PRIMARY, ACCENT_PRIMARY_HOVER, ACCENT_SECONDARY, BG_BASE, BG_ELEVATED,
     BG_ELEVATED_HI, BG_ELEVATED_PRESSED, BG_ELEVATED_TOP, BORDER_STRONG, BORDER_SUBTLE,
-    MOTION_MODAL_SECS, RADIUS_LG, RADIUS_MD, SCRIM, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY_LG,
+    HighContrastBorder, MOTION_MODAL_SECS, RADIUS_LG, RADIUS_MD, SCRIM, TEXT_PRIMARY,
-    TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_2, VAL_SPACE_3, VAL_SPACE_4, VAL_SPACE_5,
+    TEXT_SECONDARY, TYPE_BODY_LG, TYPE_CAPTION, TYPE_HEADLINE, VAL_SPACE_2, VAL_SPACE_3,
+    VAL_SPACE_4, VAL_SPACE_5,
 };
 
 // ---------------------------------------------------------------------------
@@ -230,6 +231,13 @@ where
                 Transform::from_scale(Vec3::splat(MODAL_ENTER_START_SCALE)),
                 BackgroundColor(BG_ELEVATED),
                 BorderColor::all(BORDER_STRONG),
+                // Honour `Settings::high_contrast_mode`: under HC the
+                // border boosts from `BORDER_STRONG` (#505050) to
+                // `BORDER_SUBTLE_HC` (#a0a0a0) so the modal panel
+                // edge stays clearly visible against the scrim and
+                // surface beneath. `update_high_contrast_borders` in
+                // `settings_plugin` does the per-frame swap.
+                HighContrastBorder::with_default(BORDER_STRONG),
             ))
             .with_children(build_card);
         })
@@ -320,6 +328,8 @@ pub fn spawn_modal_button<M: Component>(
     variant: ButtonVariant,
     font_res: Option<&FontResource>,
 ) {
+    #[cfg(target_os = "android")]
+    let hotkey: Option<&'static str> = None;
     let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();
     let font_label = TextFont {
         font: font_handle.clone(),
@@ -364,6 +374,7 @@ pub fn spawn_modal_button<M: Component>(
             },
             BackgroundColor(idle_bg(variant)),
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
         ))
         .with_children(|b| {
             b.spawn((Text::new(label.into()), font_label, TextColor(label_color)));

solitaire_engine/src/ui_theme.rs

@@ -93,6 +93,13 @@ pub const ACCENT_SECONDARY: Color = Color::srgb(0.882, 0.639, 0.933);
 /// from base16-eighties. `#acc267`.
 pub const STATE_SUCCESS: Color = Color::srgb(0.675, 0.761, 0.404);
 
+/// High-contrast variant of [`STATE_SUCCESS`] — `#c8e862`. Brighter
+/// lime that maintains the success hue while lifting luminance from
+/// ~0.51 → ~0.73 so the WIN MOVE scrub-bar marker stands out from
+/// the bumped notch ticks (`BORDER_SUBTLE_HC` `#a0a0a0`, L≈0.60) in
+/// high-contrast mode.
+pub const STATE_SUCCESS_HC: Color = Color::srgb(0.784, 0.910, 0.384);
+
 /// Warning — penalty signal, daily-seed expiry countdown, sync-pending
 /// status. Gold from base16-eighties. **Both** Undo and Recycle
 /// counters use this when non-zero. `#ddb26f`.
@@ -226,6 +233,82 @@ pub const BORDER_SUBTLE: Color = Color::srgba(0.208, 0.208, 0.208, 1.0);
 /// vision users.
 pub const BORDER_SUBTLE_HC: Color = Color::srgba(0.627, 0.627, 0.627, 1.0);
 
+/// Marker for entities whose [`BorderColor`] should swap to
+/// [`BORDER_SUBTLE_HC`] when `Settings::high_contrast_mode` is on.
+/// Tag any UI node where border legibility is accessibility-critical
+/// — modal panels, popovers, settings rows, focus-ring carriers —
+/// then add the `apply_high_contrast_borders` system to react to
+/// settings changes.
+///
+/// `default_color` records the off-state colour the entity was
+/// spawned with so the system can revert when HC is toggled back
+/// off. Different sites use different defaults (`BORDER_SUBTLE` for
+/// idle popover edges, `BORDER_STRONG` for active modal cards) — the
+/// marker captures whichever one applies at this entity.
+#[derive(bevy::prelude::Component, Debug, Clone, Copy)]
+pub struct HighContrastBorder {
+    /// Border colour to use when high-contrast mode is *off* — the
+    /// site's normal idle / active-state colour.
+    pub default_color: bevy::prelude::Color,
+}
+
+impl HighContrastBorder {
+    /// Convenience constructor — `HighContrastBorder::with_default(BORDER_SUBTLE)`.
+    pub const fn with_default(default_color: bevy::prelude::Color) -> Self {
+        Self { default_color }
+    }
+}
+
+/// Marker for entities whose [`BackgroundColor`] should swap to
+/// [`BORDER_SUBTLE_HC`] when `Settings::high_contrast_mode` is on.
+/// Parallel to [`HighContrastBorder`] but for sites that paint their
+/// shape via `BackgroundColor` rather than `BorderColor` —
+/// `bevy::ui` 1 px decorative strips, tick marks, fine separators
+/// often render as tiny full-bleed `Node`s, not as borders, so the
+/// border-marker pattern doesn't apply.
+///
+/// `default_color` records the off-state colour; `hc_color` the on-
+/// state colour. [`with_default`] fills `hc_color` with
+/// [`BORDER_SUBTLE_HC`] so the 90 % of sites that just need the
+/// standard subtle-border bump can continue using a one-argument
+/// constructor. [`with_hc`] overrides the HC colour for the rare
+/// site (currently only the WIN MOVE scrub-bar marker) that needs a
+/// domain-specific HC variant (`STATE_SUCCESS_HC` instead of a gray).
+///
+/// [`with_default`]: HighContrastBackground::with_default
+/// [`with_hc`]: HighContrastBackground::with_hc
+/// [`BackgroundColor`]: bevy::prelude::BackgroundColor
+#[derive(bevy::prelude::Component, Debug, Clone, Copy)]
+pub struct HighContrastBackground {
+    /// Background colour to use when high-contrast mode is *off* —
+    /// the site's normal idle / active-state colour.
+    pub default_color: bevy::prelude::Color,
+    /// Background colour to use when high-contrast mode is *on*.
+    /// Defaults to [`BORDER_SUBTLE_HC`] via [`with_default`].
+    ///
+    /// [`with_default`]: HighContrastBackground::with_default
+    pub hc_color: bevy::prelude::Color,
+}
+
+impl HighContrastBackground {
+    /// Convenience constructor — HC colour defaults to
+    /// [`BORDER_SUBTLE_HC`].
+    pub const fn with_default(default_color: bevy::prelude::Color) -> Self {
+        Self { default_color, hc_color: BORDER_SUBTLE_HC }
+    }
+
+    /// Constructor for sites whose HC colour differs from the standard
+    /// [`BORDER_SUBTLE_HC`]. Currently used by the WIN MOVE scrub-bar
+    /// marker which bumps `STATE_SUCCESS` → `STATE_SUCCESS_HC` rather
+    /// than to a neutral gray.
+    pub const fn with_hc(
+        default_color: bevy::prelude::Color,
+        hc_color: bevy::prelude::Color,
+    ) -> Self {
+        Self { default_color, hc_color }
+    }
+}
+
 /// Strong border — hover outline, focused button, active popover.
 /// `outline` from the design system. `#505050`.
 pub const BORDER_STRONG: Color = Color::srgba(0.314, 0.314, 0.314, 1.0);

solitaire_engine/src/ui_tooltip.rs

@@ -36,8 +36,8 @@ use bevy::ui::{ComputedNode, UiGlobalTransform};
 use crate::font_plugin::FontResource;
 use crate::settings_plugin::SettingsResource;
 use crate::ui_theme::{
-    BG_ELEVATED_HI, BORDER_SUBTLE, MOTION_TOOLTIP_DELAY_SECS, RADIUS_SM, TEXT_PRIMARY,
+    BG_ELEVATED_HI, BORDER_SUBTLE, HighContrastBorder, MOTION_TOOLTIP_DELAY_SECS, RADIUS_SM,
-    TYPE_CAPTION, VAL_SPACE_2, Z_TOOLTIP,
+    TEXT_PRIMARY, TYPE_CAPTION, VAL_SPACE_2, Z_TOOLTIP,
 };
 
 // ---------------------------------------------------------------------------
@@ -189,6 +189,7 @@ fn spawn_tooltip_overlay(
             },
             BackgroundColor(BG_ELEVATED_HI),
             BorderColor::all(BORDER_SUBTLE),
+            HighContrastBorder::with_default(BORDER_SUBTLE),
             Visibility::Hidden,
             // Pin above the focus ring so a tooltip on a focused element
             // is never occluded by the focus outline.

solitaire_engine/src/win_summary_plugin.rs

@@ -167,10 +167,11 @@ pub struct SessionAchievements {
 #[derive(Component, Debug)]
 pub struct WinSummaryOverlay;
 
-/// Marker on the "Play Again" button inside the win-summary modal.
+/// Marker on the "Play Again" / "Watch Replay" buttons inside the win-summary modal.
 #[derive(Component, Debug)]
 enum WinSummaryButton {
     PlayAgain,
+    WatchReplay,
 }
 
 /// Marker for one row of the win-modal score-breakdown reveal.
@@ -352,7 +353,7 @@ impl ScoreBreakdown {
         let no_undo_bonus = if undo_count == 0 { SCORE_NO_UNDO_BONUS } else { 0 };
         let multiplier = match mode {
             GameMode::Zen => 0.0,
-            GameMode::Classic | GameMode::Challenge | GameMode::TimeAttack => 1.0,
+            GameMode::Classic | GameMode::Challenge | GameMode::TimeAttack | GameMode::Difficulty(_) => 1.0,
         };
         Self {
             base,
@@ -423,6 +424,7 @@ fn mode_display_name(mode: GameMode) -> &'static str {
         GameMode::Zen => "Zen",
         GameMode::Challenge => "Challenge",
         GameMode::TimeAttack => "Time Attack",
+        GameMode::Difficulty(level) => level.label(),
     }
 }
 
@@ -601,26 +603,58 @@ fn spawn_win_summary_after_delay(
     }
 }
 
-/// Despawns the win-summary modal and fires `NewGameRequestEvent` when
+/// Handles "Play Again" and "Watch Replay" in the win-summary modal.
-/// the player presses "Play Again".
+/// Handles "Play Again" and "Watch Replay" in the win-summary modal.
 fn handle_win_summary_buttons(
     interaction_query: Query<(&Interaction, &WinSummaryButton), Changed<Interaction>>,
     overlays: Query<Entity, With<WinSummaryOverlay>>,
     mut commands: Commands,
     mut new_game: MessageWriter<NewGameRequestEvent>,
+    mut toast: MessageWriter<InfoToastEvent>,
+    history: Option<Res<crate::stats_plugin::ReplayHistoryResource>>,
+    mut playback: Option<ResMut<crate::replay_playback::ReplayPlaybackState>>,
 ) {
-    for (interaction, button) in &interaction_query {
+    // Collect all pressed buttons first to avoid moving `playback` inside the loop.
-        if *interaction != Interaction::Pressed {
+    let pressed: Vec<&WinSummaryButton> = interaction_query
-            continue;
+        .iter()
-        }
+        .filter(|(i, _)| **i == Interaction::Pressed)
+        .map(|(_, b)| b)
+        .collect();
+
+    for button in pressed {
         match button {
             WinSummaryButton::PlayAgain => {
-                // Despawn the modal.
                 for entity in &overlays {
                     commands.entity(entity).despawn();
                 }
                 new_game.write(NewGameRequestEvent::default());
             }
+            WinSummaryButton::WatchReplay => {
+                let latest = history
+                    .as_ref()
+                    .and_then(|h| h.0.replays.last())
+                    .cloned();
+                match (latest, playback.as_mut()) {
+                    (Some(replay), Some(pb)) => {
+                        for entity in &overlays {
+                            commands.entity(entity).despawn();
+                        }
+                        crate::replay_playback::start_replay_playback(
+                            &mut commands,
+                            pb,
+                            replay,
+                        );
+                    }
+                    (Some(_), None) => {
+                        toast.write(InfoToastEvent(
+                            "Replay playback not available".to_string(),
+                        ));
+                    }
+                    (None, _) => {
+                        toast.write(InfoToastEvent("No replay saved yet".to_string()));
+                    }
+                }
+            }
         }
     }
 }
@@ -810,23 +844,50 @@ fn spawn_overlay(
                     spawn_achievements_section(card, &session.names);
                 }
 
-                // Play Again button
+                // Button row: Watch Replay + Play Again side by side.
-                card.spawn((
+                card.spawn(Node {
+                    flex_direction: FlexDirection::Row,
+                    justify_content: JustifyContent::Center,
+                    column_gap: VAL_SPACE_3,
+                    margin: UiRect::top(VAL_SPACE_2),
+                    ..default()
+                })
+                .with_children(|row| {
+                    // Watch Replay (secondary style)
+                    row.spawn((
+                        WinSummaryButton::WatchReplay,
+                        Button,
+                        Node {
+                            padding: UiRect::axes(Val::Px(20.0), VAL_SPACE_3),
+                            justify_content: JustifyContent::Center,
+                            border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
+                            border: UiRect::all(Val::Px(1.0)),
+                            ..default()
+                        },
+                        BackgroundColor(Color::NONE),
+                        BorderColor::all(ACCENT_PRIMARY),
+                    ))
+                    .with_children(|b| {
+                        b.spawn((
+                            Text::new("Watch Replay"),
+                            TextFont { font_size: TYPE_BODY_LG, ..default() },
+                            TextColor(ACCENT_PRIMARY),
+                        ));
+                    });
+
+                    // Play Again (primary style)
+                    row.spawn((
                         WinSummaryButton::PlayAgain,
                         Button,
                         Node {
-                        padding: UiRect::axes(Val::Px(28.0), VAL_SPACE_3),
+                            padding: UiRect::axes(Val::Px(20.0), VAL_SPACE_3),
                             justify_content: JustifyContent::Center,
-                        margin: UiRect::top(VAL_SPACE_2),
                             border_radius: BorderRadius::all(Val::Px(RADIUS_MD)),
                             ..default()
                         },
                         BackgroundColor(ACCENT_PRIMARY),
                     ))
                     .with_children(|b| {
-                    // Append the Enter / Return glyph so keyboard players see
-                    // the accelerator on the button itself — mirrors the
-                    // chip-style hints on every modal button helper.
                         b.spawn((
                             Text::new("Play Again  \u{21B5}"),
                             TextFont { font_size: TYPE_BODY_LG, ..default() },
@@ -835,6 +896,7 @@ fn spawn_overlay(
                     });
                 });
             });
+        });
 }
 
 /// Maximum number of achievement names shown explicitly in the win modal before

solitaire_server/.env.example

@@ -0,0 +1,13 @@
+# Copy this file to .env and fill in the values.
+# The server reads these on startup via dotenvy.
+
+# SQLite database path. For local dev use a file path; for Docker use the
+# volume-mounted path (see docker-compose.yml).
+DATABASE_URL=sqlite://sol.db
+
+# HS256 signing secret for JWT tokens. Use at least 32 random characters.
+# Generate one with: openssl rand -hex 32
+JWT_SECRET=change-me-use-openssl-rand-hex-32
+
+# TCP port to listen on (optional, default 8080).
+# SERVER_PORT=8080

solitaire_server/Dockerfile

@@ -0,0 +1,57 @@
+# --- Build stage ---
+FROM rust:1.95-slim AS builder
+
+WORKDIR /build
+
+# Install musl tools for a fully static binary and sqlx-cli for compile-time
+# query checking (SQLX_OFFLINE=true skips the live-DB check at build time).
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    pkg-config \
+    libssl-dev \
+    && rm -rf /var/lib/apt/lists/*
+
+# Copy only the files needed to build the server crate.
+# Layer order: workspace manifests first so dependency fetches are cached.
+COPY Cargo.toml Cargo.lock ./
+COPY solitaire_sync/Cargo.toml ./solitaire_sync/Cargo.toml
+COPY solitaire_server/Cargo.toml ./solitaire_server/Cargo.toml
+COPY solitaire_core/Cargo.toml ./solitaire_core/Cargo.toml
+
+# Stub every crate source so `cargo fetch` succeeds without full source.
+RUN mkdir -p solitaire_sync/src solitaire_server/src solitaire_core/src && \
+    echo "pub fn _stub() {}" > solitaire_sync/src/lib.rs && \
+    echo "pub fn _stub() {}" > solitaire_core/src/lib.rs && \
+    echo "pub fn _stub() {}" > solitaire_server/src/lib.rs && \
+    echo "fn main() {}" > solitaire_server/src/main.rs
+
+RUN cargo fetch --locked
+
+# Now copy real source and build in release mode.
+COPY solitaire_core/src ./solitaire_core/src
+COPY solitaire_sync/src  ./solitaire_sync/src
+COPY solitaire_server/src ./solitaire_server/src
+COPY solitaire_server/migrations ./solitaire_server/migrations
+# sqlx offline query cache — required when SQLX_OFFLINE=true so the
+# compile-time macros don't need a live database.
+COPY .sqlx ./.sqlx
+
+ENV SQLX_OFFLINE=true
+RUN cargo build --release --locked -p solitaire_server --bin solitaire_server
+
+# --- Runtime stage ---
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY --from=builder /build/target/release/solitaire_server ./solitaire_server
+# Migrations are embedded via sqlx::migrate!("./migrations") relative to the
+# crate root at compile time — they do not need to be copied here.
+
+ENV SERVER_PORT=8080
+EXPOSE 8080
+
+ENTRYPOINT ["./solitaire_server"]

solitaire_server/docker-compose.yml

@@ -0,0 +1,25 @@
+services:
+  server:
+    build:
+      context: ..
+      dockerfile: solitaire_server/Dockerfile
+    image: solitaire-quest-server:latest
+    restart: unless-stopped
+    ports:
+      - "${SERVER_PORT:-8080}:8080"
+    volumes:
+      # SQLite database persisted outside the container.
+      - db-data:/app/data
+    environment:
+      DATABASE_URL: sqlite:///app/data/sol.db
+      JWT_SECRET: ${JWT_SECRET}
+      SERVER_PORT: 8080
+    healthcheck:
+      test: ["CMD", "wget", "-qO-", "http://localhost:8080/health"]
+      interval: 30s
+      timeout: 5s
+      retries: 3
+      start_period: 10s
+
+volumes:
+  db-data:

solitaire_server/migrations/003_refresh_tokens.sql

@@ -0,0 +1,17 @@
+-- Migration 003: refresh token rotation table
+--
+-- One row per live refresh token. Issued at login/register and rotated
+-- (old row deleted, new row inserted) on every POST /api/auth/refresh call.
+-- Cascade on user deletion means no manual cleanup is needed when an
+-- account is removed.
+
+CREATE TABLE IF NOT EXISTS refresh_tokens (
+    jti        TEXT PRIMARY KEY,                           -- UUID v4 embedded in the JWT
+    user_id    TEXT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    expires_at TEXT NOT NULL                               -- ISO 8601, mirrors the JWT exp claim
+);
+
+-- Expired-row pruning (done inline in the refresh handler) uses this index
+-- to avoid a full table scan on every refresh call.
+CREATE INDEX IF NOT EXISTS refresh_tokens_expires_at_idx
+    ON refresh_tokens(expires_at);

solitaire_server/src/auth.rs

@@ -37,10 +37,13 @@ pub struct AuthResponse {
     pub refresh_token: String,
 }
 
-/// Successful refresh response — contains only the new access token.
+/// Successful refresh response — contains the new access token and the rotated
+/// refresh token. The refresh token is always rotated: the client must store
+/// the new value and discard the old one.
 #[derive(Debug, Serialize)]
 pub struct RefreshResponse {
     pub access_token: String,
+    pub refresh_token: String,
 }
 
 // ---------------------------------------------------------------------------
@@ -73,21 +76,47 @@ pub fn make_access_token(user_id: &str, secret: &str) -> Result<String, AppError
         sub: user_id.to_string(),
         exp,
         kind: "access".to_string(),
+        jti: None,
     };
     encode(&Header::default(), &claims, &EncodingKey::from_secret(secret.as_bytes()))
         .map_err(|e| AppError::Internal(e.to_string()))
 }
 
 /// Encode a JWT refresh token (30-day expiry) for `user_id`.
-pub fn make_refresh_token(user_id: &str, secret: &str) -> Result<String, AppError> {
+///
+/// Returns `(jwt_string, jti)`. The caller must insert the jti into
+/// `refresh_tokens` before returning the JWT to the client.
+pub fn make_refresh_token(user_id: &str, secret: &str) -> Result<(String, String), AppError> {
+    let jti = Uuid::new_v4().to_string();
     let exp = (Utc::now() + chrono::Duration::days(30)).timestamp() as usize;
     let claims = Claims {
         sub: user_id.to_string(),
         exp,
         kind: "refresh".to_string(),
+        jti: Some(jti.clone()),
     };
-    encode(&Header::default(), &claims, &EncodingKey::from_secret(secret.as_bytes()))
+    let token = encode(&Header::default(), &claims, &EncodingKey::from_secret(secret.as_bytes()))
-        .map_err(|e| AppError::Internal(e.to_string()))
+        .map_err(|e| AppError::Internal(e.to_string()))?;
+    Ok((token, jti))
+}
+
+/// Insert a jti row into `refresh_tokens`. Must be called immediately after
+/// [`make_refresh_token`] and before the token is sent to the client.
+async fn store_refresh_jti(
+    pool: &sqlx::SqlitePool,
+    jti: &str,
+    user_id: &str,
+) -> Result<(), AppError> {
+    let expires_at = (Utc::now() + chrono::Duration::days(30)).to_rfc3339();
+    sqlx::query!(
+        "INSERT INTO refresh_tokens (jti, user_id, expires_at) VALUES (?, ?, ?)",
+        jti,
+        user_id,
+        expires_at
+    )
+    .execute(pool)
+    .await?;
+    Ok(())
 }
 
 // ---------------------------------------------------------------------------
@@ -160,9 +189,13 @@ pub async fn register(
     .execute(&state.pool)
     .await?;
 
+    let access_token = make_access_token(&user_id, &state.jwt_secret)?;
+    let (refresh_token, refresh_jti) = make_refresh_token(&user_id, &state.jwt_secret)?;
+    store_refresh_jti(&state.pool, &refresh_jti, &user_id).await?;
+
     Ok(Json(AuthResponse {
-        access_token: make_access_token(&user_id, &state.jwt_secret)?,
+        access_token,
-        refresh_token: make_refresh_token(&user_id, &state.jwt_secret)?,
+        refresh_token,
     }))
 }
 
@@ -190,27 +223,74 @@ pub async fn login(
         return Err(AppError::InvalidCredentials);
     }
 
+    let access_token = make_access_token(&row_id, &state.jwt_secret)?;
+    let (refresh_token, refresh_jti) = make_refresh_token(&row_id, &state.jwt_secret)?;
+    store_refresh_jti(&state.pool, &refresh_jti, &row_id).await?;
+
     Ok(Json(AuthResponse {
-        access_token: make_access_token(&row_id, &state.jwt_secret)?,
+        access_token,
-        refresh_token: make_refresh_token(&row_id, &state.jwt_secret)?,
+        refresh_token,
     }))
 }
 
-/// `POST /api/auth/refresh` — exchange a refresh token for a new access token.
+/// `POST /api/auth/refresh` — exchange a valid refresh token for a new token pair.
+///
+/// The incoming refresh token is consumed (its jti row is deleted) and a new
+/// refresh token is issued. Using a consumed token returns 401. Tokens issued
+/// before rotation was enabled (no `jti` claim) are also rejected with 401 —
+/// the player must re-login once after upgrading the server.
+///
+/// Expired rows from other sessions are pruned on each successful call.
 pub async fn refresh(
     State(state): State<AppState>,
     Json(body): Json<RefreshRequest>,
 ) -> Result<Json<RefreshResponse>, AppError> {
     let claims = validate_refresh_token(&body.refresh_token, &state.jwt_secret)?;
 
+    // Tokens without jti predate rotation — require re-login.
+    let jti = claims.jti.ok_or(AppError::Unauthorized)?;
+
+    // Verify this jti is still live (not yet consumed or from a deleted account).
+    // SQLite TEXT columns are always nullable in sqlx; flatten the double-Option.
+    let exists: Option<String> = sqlx::query_scalar!(
+        "SELECT jti FROM refresh_tokens WHERE jti = ?",
+        jti
+    )
+    .fetch_optional(&state.pool)
+    .await?
+    .flatten();
+
+    if exists.is_none() {
+        return Err(AppError::Unauthorized);
+    }
+
+    // Consume the old token before issuing new ones. If the insert below
+    // fails, the user loses this session (must re-login) — safe by design.
+    sqlx::query!("DELETE FROM refresh_tokens WHERE jti = ?", jti)
+        .execute(&state.pool)
+        .await?;
+
+    let new_access = make_access_token(&claims.sub, &state.jwt_secret)?;
+    let (new_refresh, new_jti) = make_refresh_token(&claims.sub, &state.jwt_secret)?;
+    store_refresh_jti(&state.pool, &new_jti, &claims.sub).await?;
+
+    // Prune expired rows from all sessions on each successful rotation.
+    // The expires_at index makes this a cheap index-backed scan.
+    let now = Utc::now().to_rfc3339();
+    sqlx::query!("DELETE FROM refresh_tokens WHERE expires_at < ?", now)
+        .execute(&state.pool)
+        .await?;
+
     Ok(Json(RefreshResponse {
-        access_token: make_access_token(&claims.sub, &state.jwt_secret)?,
+        access_token: new_access,
+        refresh_token: new_refresh,
     }))
 }
 
 /// `DELETE /api/account` — permanently delete the authenticated user's account.
 ///
-/// All related rows are removed via `ON DELETE CASCADE` in the schema.
+/// All related rows (sync_state, refresh_tokens, leaderboard) are removed
+/// via `ON DELETE CASCADE` in the schema.
 pub async fn delete_account(
     State(state): State<AppState>,
     user: AuthenticatedUser,
@@ -229,7 +309,7 @@ mod tests {
 
     const TEST_SECRET: &str = "test_secret_for_unit_tests_only";
 
-    fn decode_token(token: &str) -> Claims {
+    fn decode_claims(token: &str) -> Claims {
         let mut validation = Validation::default();
         validation.leeway = 60;
         decode::<Claims>(
@@ -244,27 +324,39 @@ mod tests {
     #[test]
     fn make_access_token_decodes_with_correct_claims() {
         let token = make_access_token("user-123", TEST_SECRET).unwrap();
-        let claims = decode_token(&token);
+        let claims = decode_claims(&token);
         assert_eq!(claims.sub, "user-123");
         assert_eq!(claims.kind, "access");
+        assert!(claims.jti.is_none(), "access token must not carry a jti");
         let now = Utc::now().timestamp() as usize;
-        // expiry should be roughly 24 hours in the future (allow ±60s for test execution)
         assert!(claims.exp > now + 86_400 - 60);
         assert!(claims.exp < now + 86_400 + 60);
     }
 
     #[test]
     fn make_refresh_token_decodes_with_correct_claims() {
-        let token = make_refresh_token("user-456", TEST_SECRET).unwrap();
+        let (token, jti) = make_refresh_token("user-456", TEST_SECRET).unwrap();
-        let claims = decode_token(&token);
+        let claims = decode_claims(&token);
         assert_eq!(claims.sub, "user-456");
         assert_eq!(claims.kind, "refresh");
+        assert_eq!(
+            claims.jti.as_deref(),
+            Some(jti.as_str()),
+            "jti in JWT must match returned jti"
+        );
+        assert!(!jti.is_empty(), "jti must be non-empty");
         let now = Utc::now().timestamp() as usize;
-        // expiry should be roughly 30 days in the future (allow ±60s for test execution)
         assert!(claims.exp > now + 30 * 86_400 - 60);
         assert!(claims.exp < now + 30 * 86_400 + 60);
     }
 
+    #[test]
+    fn make_refresh_token_generates_unique_jtis() {
+        let (_, jti1) = make_refresh_token("u", TEST_SECRET).unwrap();
+        let (_, jti2) = make_refresh_token("u", TEST_SECRET).unwrap();
+        assert_ne!(jti1, jti2, "each call must produce a unique jti");
+    }
+
     #[test]
     fn make_access_token_wrong_secret_fails_decode() {
         let token = make_access_token("user-789", TEST_SECRET).unwrap();
@@ -279,9 +371,9 @@ mod tests {
     #[test]
     fn access_and_refresh_tokens_have_different_kinds() {
         let access = make_access_token("u", TEST_SECRET).unwrap();
-        let refresh = make_refresh_token("u", TEST_SECRET).unwrap();
+        let (refresh, _jti) = make_refresh_token("u", TEST_SECRET).unwrap();
-        let a_claims = decode_token(&access);
+        let a_claims = decode_claims(&access);
-        let r_claims = decode_token(&refresh);
+        let r_claims = decode_claims(&refresh);
         assert_ne!(a_claims.kind, r_claims.kind);
     }
 

solitaire_server/src/lib.rs

@@ -19,15 +19,61 @@ use axum::{
     routing::{delete, get, post},
     Router,
 };
+use jsonwebtoken::{decode, DecodingKey, Validation};
 use sqlx::SqlitePool;
 use std::sync::Arc;
 use tower_governor::{
+    errors::GovernorError,
     governor::GovernorConfigBuilder,
-    key_extractor::SmartIpKeyExtractor,
+    key_extractor::{KeyExtractor, SmartIpKeyExtractor},
     GovernorLayer,
 };
 use tower_http::services::ServeDir;
 
+/// Rate-limiting key extractor for authenticated endpoints.
+///
+/// Extracts the authenticated user's UUID from the `Authorization: Bearer` JWT
+/// so each user gets their own bucket. Falls back to the client IP address when
+/// the header is absent or the token fails signature verification — this
+/// protects the server from unauthenticated request floods while ensuring
+/// legitimate users are always identified by identity rather than IP.
+///
+/// Expiry is intentionally **not** checked here: `require_auth` validates the
+/// full token (including `exp`) and returns 401. Counting an expired token
+/// against the user's bucket is harmless and avoids returning 500 (the
+/// `UnableToExtractKey` outcome) for a request that would get 401 anyway.
+#[derive(Clone)]
+struct UserIdKeyExtractor {
+    jwt_secret: String,
+}
+
+impl KeyExtractor for UserIdKeyExtractor {
+    type Key = String;
+
+    fn extract<T>(&self, req: &axum::http::Request<T>) -> Result<Self::Key, GovernorError> {
+        if let Some(user_id) = self.try_extract_user_id(req.headers()) {
+            return Ok(user_id);
+        }
+        // Fall back to IP so unauthenticated bursts don't bypass throttling.
+        SmartIpKeyExtractor
+            .extract(req)
+            .map(|ip| ip.to_string())
+    }
+}
+
+impl UserIdKeyExtractor {
+    fn try_extract_user_id(&self, headers: &axum::http::HeaderMap) -> Option<String> {
+        let value = headers.get("Authorization")?.to_str().ok()?;
+        let token = value.strip_prefix("Bearer ")?;
+        let key = DecodingKey::from_secret(self.jwt_secret.as_bytes());
+        let mut validation = Validation::default();
+        validation.validate_exp = false;
+        decode::<middleware::Claims>(token, &key, &validation)
+            .ok()
+            .map(|d| d.claims.sub)
+    }
+}
+
 /// Shared application state injected into every Axum handler via [`axum::extract::State`].
 ///
 /// Loaded once at startup so a missing `JWT_SECRET` causes an immediate startup
@@ -51,6 +97,28 @@ pub fn build_router(state: AppState) -> Router {
 /// Construct the router without rate limiting.
 ///
 /// Intended for integration tests only — do not use in production.
+/// Create an in-memory SQLite pool and run all pending migrations.
+///
+/// `max_connections(1)` is required for SQLite in-memory databases: every
+/// additional connection sees an empty schema.
+///
+/// Exposed so integration tests in other crates (e.g. `solitaire_data`) can
+/// boot a real server without duplicating the migration boilerplate.
+#[doc(hidden)]
+pub async fn build_test_pool() -> SqlitePool {
+    use sqlx::sqlite::SqlitePoolOptions;
+    let pool = SqlitePoolOptions::new()
+        .max_connections(1)
+        .connect("sqlite::memory:")
+        .await
+        .expect("failed to connect to in-memory SQLite database");
+    sqlx::migrate!("./migrations")
+        .run(&pool)
+        .await
+        .expect("failed to run database migrations");
+    pool
+}
+
 /// Uses a fixed test JWT secret (`"test_secret_32_chars_minimum_ok!"`) so
 /// integration tests do not need to set `JWT_SECRET` in the environment.
 #[doc(hidden)]
@@ -64,7 +132,7 @@ pub fn build_test_router(pool: SqlitePool) -> Router {
 
 fn build_router_inner(state: AppState, rate_limit: bool) -> Router {
     // Protected routes require a valid JWT (injected by require_auth middleware).
-    let protected = Router::new()
+    let protected_base = Router::new()
         .route("/api/sync/pull", get(sync::pull))
         .route("/api/sync/push", post(sync::push))
         .route("/api/replays", post(replays::upload))
@@ -77,6 +145,25 @@ fn build_router_inner(state: AppState, rate_limit: bool) -> Router {
             middleware::require_auth,
         ));
 
+    // Per-user rate limit on protected endpoints: 10-request burst, then 1
+    // token replenished every 10 seconds (6/min steady-state). This prevents
+    // a single compromised account from hammering the 1 MB sync/push endpoint.
+    let protected = if rate_limit {
+        let governor_conf = Arc::new(
+            GovernorConfigBuilder::default()
+                .key_extractor(UserIdKeyExtractor {
+                    jwt_secret: state.jwt_secret.clone(),
+                })
+                .per_second(10)
+                .burst_size(10)
+                .finish()
+                .expect("invalid sync governor config"),
+        );
+        protected_base.layer(GovernorLayer::new(governor_conf))
+    } else {
+        protected_base
+    };
+
     // Auth endpoints — rate-limited in production, unrestricted in tests.
     let auth_routes = Router::new()
         .route("/api/auth/register", post(auth::register))

solitaire_server/src/middleware.rs

@@ -15,7 +15,7 @@ use serde::{Deserialize, Serialize};
 
 use crate::{error::AppError, AppState};
 
-/// The claims encoded in our JWT access tokens.
+/// The claims encoded in our JWTs.
 #[derive(Debug, Serialize, Deserialize)]
 pub struct Claims {
     /// Subject — the user's UUID string.
@@ -24,6 +24,10 @@ pub struct Claims {
     pub exp: usize,
     /// Token kind: `"access"` or `"refresh"`.
     pub kind: String,
+    /// JWT ID — UUID v4 embedded in refresh tokens for rotation tracking.
+    /// Access tokens omit this field (`None`).
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub jti: Option<String>,
 }
 
 /// The authenticated user identity injected into request extensions after
@@ -135,6 +139,7 @@ mod tests {
             sub: user_id.to_string(),
             exp,
             kind: kind.to_string(),
+            jti: None,
         };
         encode(&Header::default(), &claims, &EncodingKey::from_secret(SECRET.as_bytes())).unwrap()
     }

solitaire_server/tests/server_tests.rs

@@ -347,9 +347,10 @@ async fn login_with_unknown_username_returns_401() {
     );
 }
 
-/// `POST /api/auth/refresh` with a valid refresh token returns 200 with a new access token.
+/// `POST /api/auth/refresh` with a valid refresh token returns 200 with both
+/// a new access token and a rotated refresh token.
 #[tokio::test]
-async fn refresh_returns_new_access_token() {
+async fn refresh_returns_new_access_and_refresh_tokens() {
 
     let app = build_test_router(test_pool().await);
 
@@ -368,6 +369,80 @@ async fn refresh_returns_new_access_token() {
         body["access_token"].is_string(),
         "refresh must return a new access_token"
     );
+    assert!(
+        body["refresh_token"].is_string(),
+        "refresh must return a rotated refresh_token"
+    );
+    let rotated = body["refresh_token"].as_str().unwrap();
+    assert_ne!(
+        rotated, refresh,
+        "rotated refresh token must differ from the original"
+    );
+}
+
+/// After a successful rotation, the old refresh token must be rejected (consumed).
+#[tokio::test]
+async fn consumed_refresh_token_is_rejected() {
+    let app = build_test_router(test_pool().await);
+
+    let (_access, original_refresh) =
+        register_user(app.clone(), "grace_rot", "rotation_pass").await;
+
+    // First refresh — consumes original_refresh, returns a new one.
+    let resp1 = post_json(
+        app.clone(),
+        "/api/auth/refresh",
+        serde_json::json!({ "refresh_token": original_refresh }),
+    )
+    .await;
+    assert_eq!(resp1.status(), StatusCode::OK, "first rotation must succeed");
+
+    // Second attempt with the now-consumed original token must fail.
+    let resp2 = post_json(
+        app,
+        "/api/auth/refresh",
+        serde_json::json!({ "refresh_token": original_refresh }),
+    )
+    .await;
+    assert_eq!(
+        resp2.status(),
+        StatusCode::UNAUTHORIZED,
+        "consumed refresh token must return 401"
+    );
+}
+
+/// The rotated refresh token must be usable for a subsequent refresh.
+#[tokio::test]
+async fn rotated_refresh_token_can_be_used_again() {
+    let app = build_test_router(test_pool().await);
+
+    let (_access, refresh) = register_user(app.clone(), "helen_rot", "pass_word_1").await;
+
+    // First rotation.
+    let resp1 = post_json(
+        app.clone(),
+        "/api/auth/refresh",
+        serde_json::json!({ "refresh_token": refresh }),
+    )
+    .await;
+    assert_eq!(resp1.status(), StatusCode::OK);
+    let rotated = body_json(resp1).await;
+    let second_refresh = rotated["refresh_token"].as_str().unwrap().to_string();
+
+    // Second rotation using the first rotated token.
+    let resp2 = post_json(
+        app,
+        "/api/auth/refresh",
+        serde_json::json!({ "refresh_token": second_refresh }),
+    )
+    .await;
+    assert_eq!(
+        resp2.status(),
+        StatusCode::OK,
+        "rotated token must work for a second rotation"
+    );
+    let body2 = body_json(resp2).await;
+    assert!(body2["access_token"].is_string());
 }
 
 /// Supplying an access token to `POST /api/auth/refresh` must be rejected because
@@ -1448,6 +1523,68 @@ async fn auth_rate_limit_returns_429_on_11th_request() {
     );
 }
 
+/// The 11th `POST /api/sync/push` from the same authenticated user within the
+/// rate-limit window must return 429 Too Many Requests.
+///
+/// Uses [`solitaire_server::build_router`] (rate limiting ON) so the
+/// GovernorLayer is applied. We register a fresh account, then send 10 pushes
+/// (consuming the burst allowance), and assert the 11th is throttled.
+///
+/// Note: the push body deliberately omits valid `SyncPayload` structure —
+/// that would return 422, but the rate limiter fires before deserialization,
+/// so the response code for the first 10 is 422 and for the 11th is 429.
+/// The test only asserts `!= 429` for requests 1–10 and `== 429` for request 11.
+#[tokio::test]
+async fn sync_push_rate_limit_returns_429_on_11th_request() {
+    let state = solitaire_server::AppState {
+        pool: test_pool().await,
+        jwt_secret: TEST_SECRET.to_string(),
+    };
+    let app = solitaire_server::build_router(state);
+
+    // Register a user to obtain a valid JWT for the UserIdKeyExtractor.
+    let (token, _) = register_user(app.clone(), "sync_ratelimit_user", "p4ssword!").await;
+
+    let stub_body = serde_json::to_vec(&serde_json::json!({})).unwrap();
+
+    // First 10 requests consume the burst allowance (burst_size = 10).
+    // The body is intentionally invalid — the rate limiter fires before
+    // deserialization, so we get 422 rather than 200. We only assert != 429.
+    for i in 0..10 {
+        let req = Request::builder()
+            .method("POST")
+            .uri("/api/sync/push")
+            .header("content-type", "application/json")
+            .header("Authorization", format!("Bearer {token}"))
+            .header("x-forwarded-for", TEST_CLIENT_IP)
+            .body(Body::from(stub_body.clone()))
+            .expect("failed to build request");
+        let resp = app.clone().oneshot(req).await.expect("oneshot failed");
+        assert_ne!(
+            resp.status(),
+            StatusCode::TOO_MANY_REQUESTS,
+            "request {} of 10 must not be rate-limited",
+            i + 1
+        );
+    }
+
+    // The 11th request must be throttled.
+    let req = Request::builder()
+        .method("POST")
+        .uri("/api/sync/push")
+        .header("content-type", "application/json")
+        .header("Authorization", format!("Bearer {token}"))
+        .header("x-forwarded-for", TEST_CLIENT_IP)
+        .body(Body::from(stub_body))
+        .expect("failed to build 11th request");
+    let resp = app.clone().oneshot(req).await.expect("oneshot failed");
+    assert_eq!(
+        resp.status(),
+        StatusCode::TOO_MANY_REQUESTS,
+        "11th sync push must be rate-limited with 429"
+    );
+}
+
 // ---------------------------------------------------------------------------
 // Replay endpoints
 //