docs: CHANGELOG + SESSION_HANDOFF refresh for v0.15.0

CHANGELOG gains a [0.15.0] section covering 7 commits since
v0.14.0: Bevy default-features trim (51 transitive crates dropped),
in-engine replay playback core + overlay banner + Stats button
wiring, rolling replay history (last 8 wins) with selector UI,
"Cinephile" achievement (#19), and the Klondike solver + "Winnable
deals only" toggle.

The bottom-of-file compare links thread the new tag into the chain.
Test count updated to 1178.

SESSION_HANDOFF rewritten for the post-v0.15.0 state. Open punch
list collapsed to two release-prep items (smoke-test, desktop
packaging) and six fresh next-round candidates: solver-driven
hints (now unblocked), playback-rate slider, solver progress
overlay, solver-on-async-compute, per-deal "won previously"
indicator, replay sharing. Resume prompt asks A–E.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.sqlx/query-3a9bd2e51b2389da5b7e85f26806fcffa896748e0b589d216cf60827fc3857a9.json

@@ -0,0 +1,68 @@
+{
+  "db_name": "SQLite",
+  "query": "SELECT\n              r.id              AS \"id!: String\",\n              u.username        AS \"username!: String\",\n              r.seed            AS \"seed!: i64\",\n              r.draw_mode       AS \"draw_mode!: String\",\n              r.mode            AS \"mode!: String\",\n              r.time_seconds    AS \"time_seconds!: i64\",\n              r.final_score     AS \"final_score!: i64\",\n              r.recorded_at     AS \"recorded_at!: String\",\n              r.received_at     AS \"received_at!: String\"\n           FROM replays r\n           JOIN users   u ON u.id = r.user_id\n           ORDER BY r.received_at DESC\n           LIMIT ?",
+  "describe": {
+    "columns": [
+      {
+        "name": "id!: String",
+        "ordinal": 0,
+        "type_info": "Text"
+      },
+      {
+        "name": "username!: String",
+        "ordinal": 1,
+        "type_info": "Text"
+      },
+      {
+        "name": "seed!: i64",
+        "ordinal": 2,
+        "type_info": "Integer"
+      },
+      {
+        "name": "draw_mode!: String",
+        "ordinal": 3,
+        "type_info": "Text"
+      },
+      {
+        "name": "mode!: String",
+        "ordinal": 4,
+        "type_info": "Text"
+      },
+      {
+        "name": "time_seconds!: i64",
+        "ordinal": 5,
+        "type_info": "Integer"
+      },
+      {
+        "name": "final_score!: i64",
+        "ordinal": 6,
+        "type_info": "Integer"
+      },
+      {
+        "name": "recorded_at!: String",
+        "ordinal": 7,
+        "type_info": "Text"
+      },
+      {
+        "name": "received_at!: String",
+        "ordinal": 8,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      true,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false,
+      false
+    ]
+  },
+  "hash": "3a9bd2e51b2389da5b7e85f26806fcffa896748e0b589d216cf60827fc3857a9"
+}

.sqlx/query-5bc1984044bc792c2e9577a159ca22789469df14cb25144451f37e8cdad8165c.json

@@ -0,0 +1,20 @@
+{
+  "db_name": "SQLite",
+  "query": "SELECT replay_json FROM replays WHERE id = ?",
+  "describe": {
+    "columns": [
+      {
+        "name": "replay_json",
+        "ordinal": 0,
+        "type_info": "Text"
+      }
+    ],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": [
+      false
+    ]
+  },
+  "hash": "5bc1984044bc792c2e9577a159ca22789469df14cb25144451f37e8cdad8165c"
+}

.sqlx/query-6a36a96faa9d9b423aae3b72b0c049a1489b67ca2361581b2300bb4ee0bc9e2f.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "INSERT INTO replays (\n              id, user_id, seed, draw_mode, mode, time_seconds, final_score,\n              recorded_at, received_at, replay_json\n           ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 10
+    },
+    "nullable": []
+  },
+  "hash": "6a36a96faa9d9b423aae3b72b0c049a1489b67ca2361581b2300bb4ee0bc9e2f"
+}

ARCHITECTURE.md

@@ -716,11 +716,14 @@ pub struct AchievementDef {
 | `speed_and_skill` | ??? | Win < 90s without undo | Yes | Card back #4 |
 | `comeback` | ??? | Win after 3+ stock recycles | Yes | Background #4 |
 | `zen_winner` | ??? | Win in Zen Mode | Yes | Badge |
+| `cinephile` | Cinephile | Watch a saved replay all the way through | No | — |
 
 ### Evaluation Timing
 
 Achievement conditions are evaluated by `AchievementPlugin` on every `GameWonEvent` and `StateChangedEvent`. The plugin calls `solitaire_core::check_achievements()` which returns a `Vec<AchievementDef>` of newly unlocked achievements. The plugin then fires `AchievementUnlockedEvent` for each, which the toast and persistence systems handle independently.
 
+A small number of achievements are *event-driven* rather than condition-driven: their `AchievementDef::condition` always returns `false` and their unlock is written from a dedicated observer system instead. `cinephile` is the canonical example — it unlocks when `ReplayPlaybackState` transitions from `Playing` to `Completed` (a saved replay watched to its natural end). The Stop button transitions `Playing → Inactive` directly without entering `Completed`, so manual aborts do not unlock the achievement.
+
 ---
 
 ## 12. Progression System

CHANGELOG.md

@@ -8,6 +8,159 @@ project follows [Semantic Versioning](https://semver.org/).
 
 _Nothing yet._
 
+## [0.15.0] — 2026-05-02
+
+In-engine replay playback, the Klondike solver + "Winnable deals
+only" toggle, a 19th achievement, rolling replay history, and a
+significant build-time / binary-size win from disabling Bevy's
+default audio stack.
+
+### Added
+
+- **In-engine replay playback** for the Stats overlay's Watch Replay
+  button. New `ReplayPlaybackPlugin` runs a state machine
+  (Inactive / Playing / Completed) that resets the live game to the
+  recorded deal and ticks through `replay.moves` at
+  `REPLAY_MOVE_INTERVAL_SECS` (0.45 s) firing the canonical
+  `MoveRequestEvent` / `DrawRequestEvent` per recorded move.
+  Recording is suppressed during playback so replays don't re-record
+  themselves.
+- **Replay overlay banner** (`ReplayOverlayPlugin`) anchored to the
+  top of the window during playback. Shows "Replay" label, "Move N
+  of M" progress, and a Stop button. Z-order leaves modals
+  (Settings, Pause, Help) free to render on top so the player can
+  adjust audio mid-replay.
+- **Rolling replay history** at `<data_dir>/replays.json` capped at
+  8 entries. Replaces the single-slot `latest_replay.json` (legacy
+  file is migrated forward on first launch via
+  `migrate_legacy_latest_replay`). Stats overlay gains a Prev / Next
+  selector and a "Replay N / M" caption so the player can revisit
+  older wins.
+- **"Cinephile" achievement** (#19). Unlocks the first time
+  `ReplayPlaybackState` transitions Playing → Completed (i.e. the
+  replay played out to its end without the player pressing Stop).
+  Stop transitions Playing → Inactive directly so it doesn't count.
+- **Klondike solver** in `solitaire_core::solver`. Iterative-DFS
+  with memoisation on a 64-bit canonical state hash, two budget
+  knobs (move_budget + state_budget) for pathological cases, and a
+  three-state `SolverResult` (Winnable / Unwinnable / Inconclusive).
+  Median solve time 2 ms; pathological inconclusives cap near
+  120 ms. Pure logic — `solitaire_core` keeps no Bevy or I/O.
+- **"Winnable deals only" toggle** in Settings → Gameplay (default
+  off). When on, `handle_new_game` walks seed N, N+1, N+2, …
+  through `try_solve` until it finds Winnable or Inconclusive,
+  capped at `SOLVER_DEAL_RETRY_CAP` (50) attempts. Daily
+  challenges, replays, and explicit-seed requests bypass the
+  solver — only random Classic deals are gated.
+
+### Changed
+
+- **Bevy default-feature trim** (`bevy = { default-features = false,
+  features = [...] }` in workspace Cargo.toml) drops 51 transitive
+  crates including the `bevy_audio` → rodio → cpal 0.15 + symphonia
+  chain that the project doesn't use (kira handles audio directly).
+  The retained feature list is curated to exactly what the engine
+  uses; `solitaire_wasm` is unaffected because it doesn't depend on
+  bevy.
+
+### Stats
+
+- 1178 passing tests (was 1134 at v0.14.0 close).
+- Zero clippy warnings under `--workspace --all-targets -- -D warnings`.
+
+## [0.14.0] — 2026-05-02
+
+Two threads land in v0.14.0: the second half of the post-v0.12.0 UX
+candidate list (theme thumbnails, daily-challenge calendar, Time Attack
+auto-save, per-mode bests, time-bonus multiplier) plus a **major new
+feature** — the replay pipeline (record → upload → web viewer). Three
+Quat-reported bugs from a smoke-test round shipped alongside.
+
+### Added
+
+- **Theme-picker thumbnails** in Settings → Cosmetic. Each theme chip
+  renders a small Ace-of-Spades + back preview pair via the existing
+  `rasterize_svg` path. Cached per theme in a new
+  `ThemeThumbnailCache`. Themes that lack a preview SVG fall back to
+  a transparent placeholder rather than crashing.
+- **14-day daily-challenge calendar** in the Profile modal. Horizontal
+  row of dots showing the trailing two weeks; today's dot is ringed
+  in `ACCENT_PRIMARY`, completed days fill `STATE_SUCCESS`, missed
+  days fill `BG_ELEVATED`. Caption above the row reads "Current
+  streak: N · Longest: M".
+- **Time Attack session auto-save** to `<data_dir>/time_attack_session.json`,
+  atomic .tmp + rename. 30-second auto-save while a session is active,
+  plus on `AppExit`. Sessions whose 10-minute window expired in real
+  time while the app was closed are discarded on load. Classic, Zen,
+  and Challenge already auto-saved correctly via `game_state.json` —
+  Time Attack was the only mode missing session-level persistence.
+- **Per-mode best-score and fastest-win readouts** in the Stats screen.
+  `StatsSnapshot` gains six `#[serde(default)]` fields (Classic / Zen
+  / Challenge × best_score + fastest_win_seconds). Stats screen renders
+  a "Per-mode bests" section between the primary cell grid and
+  progression. Lifetime totals continue to roll all modes together.
+- **Time-bonus multiplier slider** in Settings → Gameplay (0.0–2.0,
+  0.1 steps, default 1.0, "Off" label at zero). Cosmetic only —
+  multiplies the time-bonus shown in the win modal but does NOT
+  affect achievement unlock thresholds (those still use the raw
+  unmultiplied score).
+- **Win-replay recording + storage.** Every move during a successful
+  game appends to a `RecordingReplay` resource; on `GameWonEvent`
+  the recording freezes into a `Replay` (seed + draw_mode + mode +
+  score + time + ordered move list) and persists to
+  `<data_dir>/latest_replay.json` atomically. Single-slot — overwrites
+  on every win.
+- **"Watch replay" button** in the Stats overlay. Shows the latest
+  win's caption and surfaces a button that loads the replay (button
+  fires an `InfoToastEvent` describing the replay; full in-engine
+  playback is deferred to a future build).
+- **Replay upload + fetch endpoints** on the server. `POST /api/replays`
+  accepts a `Replay` JSON; `GET /api/replays/:id` returns it. JWT-gated
+  with the existing auth middleware. Engine uploads winning replays
+  automatically when the player has cloud sync configured.
+- **`solitaire_wasm` crate** — new workspace member compiling
+  replay-relevant `solitaire_core` types to WebAssembly so a
+  browser can re-execute a replay client-side. No-std-friendly
+  surface; `wasm-bindgen` glue.
+- **Web replay viewer** served from the Solitaire server.
+  `GET /replays/:id` returns HTML + CSS + the wasm bundle that
+  fetches the replay JSON, rasterises a deal from the seed, and
+  animates the recorded moves.
+- **Card flight animations on the web side** so the browser viewer
+  reads as a real game replay rather than a static dump.
+
+### Fixed
+
+- **Multi-card lift validation.** `solitaire_core::rules::is_valid_tableau_sequence`
+  rejects a moved stack whose adjacent cards don't form a descending
+  alternating-colour run. Previously a player could lift any
+  multi-card selection and drop it as long as the bottom landed
+  legally. Wired into `move_cards`'s tableau-destination branch.
+- **Softlock detection.** `has_legal_moves` rewritten to walk every
+  potential move source (every stock card, every waste card, the
+  face-up top of every tableau column) and check it against every
+  foundation and every tableau. Previously the heuristic
+  early-returned `true` whenever stock had cards — players got
+  stuck in unwinnable end-states with no end-game screen.
+  `GameOverScreen` now actually fires for true softlocks. Quat's
+  exact reproduction case is pinned by a new test.
+- **Deal-tween information leak.** New-game now snaps every card
+  sprite to the stock pile position before writing
+  `StateChangedEvent`, so all 52 cards animate from a single point
+  during the deal. Previously the sprites started from their
+  previous-game positions, briefly revealing the prior deal.
+
+### Documentation
+
+- `SESSION_HANDOFF.md` refreshed for the Quat smoke-test round
+  including investigation findings on solver decisions and
+  dependency duplicates.
+
+### Stats
+
+- 1134 passing tests (was 1053 at v0.13.0 close).
+- Zero clippy warnings under `--workspace --all-targets -- -D warnings`.
+
 ## [0.13.0] — 2026-05-02
 
 Third UX iteration round on top of v0.12.0. Six handoff candidates
@@ -312,7 +465,9 @@ with no PNG artwork yet.
   CREDITS.md, persistent window geometry, mode-launcher Home repurpose,
   client-side sync round-trip integration tests.
 
-[Unreleased]: https://github.com/funman300/Rusty_Solitaire/compare/v0.13.0...HEAD
+[Unreleased]: https://github.com/funman300/Rusty_Solitaire/compare/v0.15.0...HEAD
+[0.15.0]: https://github.com/funman300/Rusty_Solitaire/compare/v0.14.0...v0.15.0
+[0.14.0]: https://github.com/funman300/Rusty_Solitaire/compare/v0.13.0...v0.14.0
 [0.13.0]: https://github.com/funman300/Rusty_Solitaire/compare/v0.12.0...v0.13.0
 [0.12.0]: https://github.com/funman300/Rusty_Solitaire/compare/v0.11.0...v0.12.0
 [0.11.0]: https://github.com/funman300/Rusty_Solitaire/compare/v0.10.0...v0.11.0

Cargo.toml

@@ -7,6 +7,7 @@ members = [
     "solitaire_server",
     "solitaire_app",
     "solitaire_assetgen",
+    "solitaire_wasm",
 ]
 resolver = "2"
 
@@ -35,7 +36,46 @@ solitaire_sync   = { path = "solitaire_sync" }
 solitaire_data   = { path = "solitaire_data" }
 solitaire_engine = { path = "solitaire_engine" }
 
-bevy = "0.18"
+# Bevy with `default-features = false` to avoid the unused
+# `bevy_audio → rodio + symphonia + cpal 0.15 + alsa 0.9` chain.
+# Audio is handled directly by `kira` in `audio_plugin.rs`, so the
+# `bevy_audio` feature is intentionally omitted. The features below
+# enumerate every leaf of the standard `2d` + `ui` meta-features that
+# we actually use; new features should only be added with a
+# corresponding use site.
+bevy = { version = "0.18", default-features = false, features = [
+    # default_app
+    "async_executor",
+    "bevy_asset",
+    "bevy_input_focus",
+    "bevy_log",
+    "bevy_state",
+    "bevy_window",
+    "custom_cursor",
+    "reflect_auto_register",
+    # default_platform (desktop subset; no android/wayland/webgl/gilrs/sysinfo)
+    "std",
+    "bevy_winit",
+    "default_font",
+    "multi_threaded",
+    "x11",
+    # common_api
+    "bevy_color",
+    "bevy_image",
+    "bevy_mesh",
+    "bevy_shader",
+    "bevy_text",
+    "png",
+    # 2d rendering
+    "bevy_camera",
+    "bevy_render",
+    "bevy_core_pipeline",
+    "bevy_sprite",
+    "bevy_sprite_render",
+    # UI rendering
+    "bevy_ui",
+    "bevy_ui_render",
+] }
 kira = "0.12"
 
 # SVG rasterisation pipeline for the runtime card-theme system.

README.md

@@ -22,7 +22,7 @@ optional self-hosted sync so your stats follow you across machines.
   move within picker rows, Enter activates; works across every modal and
   the HUD action bar
 - **Progression** — XP, levels, unlockable card backs and backgrounds
-- **18 Achievements** — including secret ones
+- **19 Achievements** — including secret ones
 - **Daily Challenge** — server-seeded so every player worldwide gets the
   same deal
 - **Leaderboard** — opt-in, powered by your own self-hosted server

SESSION_HANDOFF.md

@@ -1,20 +1,24 @@
-# Solitaire Quest — UX Overhaul Session Handoff
+# Solitaire Quest — Session Handoff
 
-**Last updated:** 2026-05-02 (session 7, late-late) — Third UX iteration round complete on top of v0.12.0. Six post-handoff candidates shipped plus two code-review fixes. Ready to tag v0.13.0.
+**Last updated:** 2026-05-02 (session 9, post-v0.14.0 release prep) — v0.14.0 cut. The Quat bug fixes, the rest of the v0.13.0 candidate list, and the entire replay → upload → web-viewer pipeline are all bundled in this release. Direction now opens for the next round.
 
 ## Status at pause
 
-- **HEAD:** doc-commit closing this round (CHANGELOG + handoff). Local master has the impending tag at this commit.
+- **HEAD on origin:** v0.14.0's tag commit (CHANGELOG + handoff refresh).
 - **Working tree:** clean apart from untracked `CARD_PLAN.md` (intentional).
 - **Build:** `cargo clippy --workspace --all-targets -- -D warnings` clean.
-- **Tests:** **1053 passed / 0 failed** across the workspace (+22 from v0.12.0's 1031 baseline).
+- **Tests:** **1134 passed / 0 failed** across the workspace.
-- **Tags on origin:** `v0.9.0`, `v0.10.0`, `v0.11.0`, `v0.12.0`. v0.13.0 is the next tag.
+- **Tags on origin:** `v0.9.0`, `v0.10.0`, `v0.11.0`, `v0.12.0`, `v0.13.0`, `v0.14.0`.
 
 ## Where we are
 
-Post-v0.12.0 the handoff listed six "next-round candidates" — every one shipped today plus two code-review fixes (font handling unified to bundled-only, sccache wiring removed). v0.13.0 is the right slice.
+v0.14.0 is the largest release since the card-theme system. Three threads land together:
 
-The candidate list is exhausted again. Direction is open.
+1. **The remaining v0.13.0-era UX candidates** — theme thumbnails, daily-challenge calendar, Time Attack auto-save, per-mode bests, time-bonus multiplier slider.
+2. **Quat smoke-test bug fixes** — multi-card move validation, softlock detection, deal-tween information leak.
+3. **The replay pipeline** — record on win, persist to disk, upload to server, view in browser via a new `solitaire_wasm` crate. The biggest single feature since the card-theme system.
+
+The card-flight web animations and replay E2E test coverage close out the pipeline.
 
 ### Design direction (unchanged)
 
@@ -26,42 +30,64 @@ The candidate list is exhausted again. Direction is open.
 
 `github.com/funman300/Rusty_Solitaire` is the canonical repo. Always push there.
 
-## Session 7 round 3 (shipped 2026-05-02 late-late) — v0.13.0
+## Session 8 + 9 (shipped 2026-05-02) — v0.14.0
+
+### v0.13.0-era UX candidates (had landed but missed v0.13.0's tag)
 
 | Area | Commit | What landed |
 |---|---|---|
-| Font fix | `17f9b51` | Code-review fix: bundle FiraMono via `include_bytes!()` in both `font_plugin` and `svg_loader`; drop `load_system_fonts`, drop the lenient resolver, drop the CSS-generic fallbacks. New `bundled_font_resolver` always returns the single bundled face. Parse failure aborts with a clear error. |
+| Theme thumbnails | `ba527de` | Each Settings → Cosmetic theme chip renders an Ace + back preview pair via `rasterize_svg`. Cached per theme. Missing-SVG themes show a transparent placeholder rather than crashing. |
-| sccache removal | `13dd44b` | Code-review fix: deleted `.cargo/config.toml` and the `.cargo` directory. Plain `cargo build` works without per-project setup. |
+| Daily-challenge calendar | `1a10476` | 14-dot horizontal calendar in the Profile modal. Today is ringed, completed days fill `STATE_SUCCESS`, missed days fill `BG_ELEVATED`. Caption: "Current streak: N · Longest: M". `PlayerProgress` gains `daily_challenge_history` (capped at 365) and `daily_challenge_longest_streak`. |
-| Wave 1 bundle | `ddc8f27` | **Tooltip-delay slider** in Settings → Gameplay (0.0–1.5 s, 0.1 s steps, "Instant" label at zero). **Win-streak fire animation** at thresholds [3, 5, 10] via new `WinStreakMilestoneEvent`. **Score-breakdown reveal on win modal** with per-row stagger (Base / Time bonus / No-undo / Multiplier / Total), respects `AnimSpeed::Instant`. |
+| Time Attack auto-save | `0001432` | New sibling `time_attack_session.json` next to `game_state.json`. Atomic .tmp + rename. 30 s auto-save while active + on `AppExit`. Sessions whose 10-min window expired in real time while the app was closed are discarded on load. |
-| Card-back theming | `7ed4f2c` | The active theme's `back.svg` now actually drives the face-down sprite. Legacy `back_N.png` picker remains as a fallback for themes without a back; Settings caption surfaces when the override is in effect. |
+| Per-mode bests | `3984231` | StatsSnapshot gains six `#[serde(default)]` fields (Classic / Zen / Challenge × best_score + fastest_win_seconds). Stats screen renders a "Per-mode bests" section. Lifetime totals continue to roll all modes together. |
-| Drag-with-keyboard | `a0fc0d2` | Tab → Enter → arrows → Enter completes a move without a mouse. New `KeyboardDragState` resource; mutual exclusion with mouse drag via `KEYBOARD_DRAG_TOUCH_ID` sentinel. Help + onboarding hotkey lists updated. |
+| Time-bonus slider | `89c51ab` | Settings → Gameplay slider 0.0–2.0, default 1.0, "Off" at zero. Multiplies the time-bonus shown in the win modal. Cosmetic only — does NOT affect achievement unlock thresholds. |
-| Right-click radial | `b37f0cb` | Hold RMB on a face-up card → ring of icons at the cursor, one per legal destination; release over an icon → `MoveRequestEvent`. New `RadialMenuPlugin`. Help controls reference gains a "Mouse" section. |
 
-## Open punch list — release prep
+### Quat smoke-test bug fixes
 
-1. **Push** the unpushed commits to origin (5 commits now: 17f9b51, 13dd44b, ddc8f27, 7ed4f2c, a0fc0d2, b37f0cb, plus the impending doc commit).
+| Area | Commit | What landed |
-2. **Tag v0.13.0** at the doc-commit HEAD.
+|---|---|---|
-3. **Desktop packaging** per `ARCHITECTURE.md §17`. The Arch PKGBUILD exists in `/home/manage/solitaire-quest-pkgbuild/` (separate repo). Pending: app icon, macOS `.icns` + notarisation cert, Windows `.ico` + Authenticode cert, AppImage recipe.
+| Move validation (#1) | `f1aeb24` | `solitaire_core::rules::is_valid_tableau_sequence(&[Card]) -> bool` checks every adjacent pair in a moved stack descends one rank with alternating colour. Wired into `move_cards`. Closes the bug where any multi-card lift could be dropped as long as the bottom landed legally. |
+| Deal-tween leak (#4) | `3eabc14` | New-game snaps every card sprite to the stock pile position before writing `StateChangedEvent`, so all 52 cards animate from a single deck point during the deal. Previously sprites started from previous-game positions, briefly revealing the prior deal. |
+| Softlock detection (#2) | `2716472` | `has_legal_moves` rewritten: walks every potential move source (every stock card, every waste card, the face-up top of every tableau column) against every foundation and every tableau. Previous heuristic returned `true` whenever stock had cards, hiding genuine softlocks. `GameOverScreen` now actually fires for true softlocks. |
+| End-game screen (#3) | — | Resolved as downstream of #2. The pre-existing `GameOverScreen` and `WinSummaryOverlay` already cover the close-out paths; the softlock screen just never spawned because the old `has_legal_moves` lied. |
 
-## Open punch list — UX iteration (next-round candidates)
+### Replay pipeline (the major feature)
 
-The v0.13.0 list is exhausted. Fresh candidates for a future round:
+| Area | Commit | What landed |
+|---|---|---|
+| Replay storage | `42535f5` | `solitaire_data::replay::Replay` (seed + draw_mode + mode + score + time + recorded date + ordered move list) and atomic save/load helpers under `<data_dir>/latest_replay.json`. Schema v1; `load` returns None for any other version. |
+| Engine recording | `57d1c58` | `RecordingReplay` resource + `ReplayPath` settings. Every successful `MoveRequestEvent` / `DrawRequestEvent` appends to recording; `GameWonEvent` freezes the recording into a `Replay` and persists. Undo intentionally not recorded. New game clears the recording. |
+| Stats button | `d9f36bf` | Stats overlay surfaces a "Latest win:" caption + "Watch replay" button. Loads from disk via `LatestReplayResource`. (Full in-engine playback deferred — button currently fires an `InfoToastEvent` describing the replay.) |
+| Server upload + fetch | `93182fa` | `POST /api/replays` accepts a `Replay` JSON; `GET /api/replays/:id` returns it. JWT-gated. SQL migration for the new `replays` table. |
+| Engine sync | `23c9704` | Engine uploads winning replays automatically when the player has cloud sync configured. Re-uses the existing JWT/refresh-token flow. |
+| WASM crate | `5bed43e` | New workspace member `solitaire_wasm` compiles replay-relevant `solitaire_core` types to WebAssembly so a browser can re-execute a replay client-side. `wasm-bindgen` glue. |
+| Web viewer | `07b8ecd` | `GET /replays/:id` returns HTML + CSS + the wasm bundle. Browser fetches the replay JSON, rasterises a deal from the seed, and animates the recorded moves. |
+| E2E coverage | `3081505` | Server tests covering the full upload → fetch round-trip via `axum::test`. |
+| Web flight anim | `1fcd032` | Card-flight tweens on the web side so the browser viewer reads as a real game replay rather than a static dump. |
 
-- **In-game daily-challenge calendar** — currently the daily challenge fires once on launch; a Settings or Profile-side calendar showing past days' completion / streak status would make the progression visible.
+## Open punch list
-- **Card-art preview in the theme picker** — Settings → Cosmetic shows theme name only; rendering the theme's Ace-of-Spades + back side-by-side as a thumbnail would make picking faster.
+
-- **Per-mode high-score readout** in the Stats screen. Currently lifetime stats roll all modes together.
+### Release prep
-- **Auto-save in-progress games** in Zen / Time Attack so players who close the window mid-session don't lose their state.
+1. **Smoke-test on the alex machine** after pulling — confirm Quat's three bug fixes hold up in real gameplay, and try the new replay button + web viewer end-to-end.
-- **Configurable scoring weights** for the curious — Settings → Gameplay slider for time-bonus magnitude. Cosmetic but power-user appealing.
+2. **Desktop packaging** per `ARCHITECTURE.md §17`. The Arch PKGBUILD exists in `/home/manage/solitaire-quest-pkgbuild/` (separate repo). Pending: app icon, macOS `.icns` + notarisation cert, Windows `.ico` + Authenticode cert, AppImage recipe.
-- **Replay a winning game** — record the seed + move list at win time and offer "watch replay" from the Stats screen.
+
+### UX iteration (next-round candidates)
+
+- **Solver-at-deal toggle** (Quat investigation #1, still deferred): add a Settings → Gameplay toggle "Winnable deals only" rather than baking solver-only into every deal. Lightest middle ground.
+- **Disable Bevy's default audio feature** (Quat investigation #2, still deferred): one-line `default-features = false` swap on the workspace `bevy =` line, re-enable explicitly the features the engine uses (`render`, `bevy_winit`, `2d`, `bevy_window`, `png`, `bevy_text`, `bevy_ui`, `bevy_log`, `bevy_asset`, `default_font`, `bevy_state`). Drops ~50 transitive crates including the rodio + symphonia stack the project doesn't use (kira handles audio).
+- **In-engine replay playback** — promote the "Watch replay" button from a stub toast to a real playback overlay that re-runs the recorded moves with `CardAnimation` tweens. The wasm crate already proves the playback math; the in-engine version reuses the same execute logic against the live game state.
+- **Per-replay history** — currently single-slot at `latest_replay.json`. A "best replay per mode" bucket or a recent-N rolling list would let players revisit notable wins.
+- **Solver-driven hint system** — extend the existing hint toggle so a deal-time solver provides higher-quality hints (currently a heuristic). Requires the solver from the toggle work above.
+- **Achievement: "won via replay path"** — track when a player wins a deal whose previously-saved replay also won the same deal. Mostly fun; trivial scope.
 
 ## Card-theme system (CARD_PLAN.md, fully shipped)
 
-Seven phases landed across `b8fb3fb` → `924a1e2` in v0.11.0; v0.13.0's `7ed4f2c` finally consumes the per-theme `back.svg`. End-to-end:
+Seven phases landed across `b8fb3fb` → `924a1e2` in v0.11.0; v0.13.0's `7ed4f2c` consumes the per-theme `back.svg`; v0.14.0's `ba527de` adds preview thumbnails. End-to-end:
 
 - **Bundled default theme** ships in the binary via `embedded://` — 52 hayeah/playing-cards-assets SVGs + a midnight-purple `back.svg`.
 - **User themes** under `themes://`. Drop a directory containing `theme.ron` + 53 SVGs.
 - **Importer** at `solitaire_engine::theme::import_theme(zip)` validates archives and atomically unpacks.
-- **Picker UI** in Settings → Cosmetic; the active theme's `back` overrides the legacy `back_N.png` picker when present.
+- **Picker UI** in Settings → Cosmetic; thumbnails + the active theme's `back` override the legacy `back_N.png` picker when present.
 
 ## Resume prompt
 
@@ -69,17 +95,17 @@ Seven phases landed across `b8fb3fb` → `924a1e2` in v0.11.0; v0.13.0's `7ed4f2
 You are a senior Rust + Bevy developer working on Solitaire Quest.
 Working directory: <Rusty_Solitaire clone path on this machine — local
 directory may still be named Rusty_Solitare from earlier; that's fine>.
-Branch: master. Direction is OPEN — three UX iteration rounds shipped
+Branch: master. Direction is OPEN — v0.14.0 just shipped covering the
-and v0.13.0 is ready to tag.
+Quat bug fixes, the v0.13.0 candidate tail, and the entire
+replay-pipeline feature.
 
-State: HEAD at the doc-commit closing session 7 round 3. Local master
+State: HEAD at v0.14.0. Working tree clean apart from untracked
-is several commits ahead of origin and unpushed. Working tree clean
+CARD_PLAN.md (intentional).
-apart from untracked CARD_PLAN.md (intentional).
 Build: cargo clippy --workspace --all-targets -- -D warnings clean.
-Tests: 1053 passed / 0 failed.
+Tests: 1134 passed / 0 failed.
 
 READ FIRST (in order, before doing anything):
-  1. SESSION_HANDOFF.md  — full state, session 7 changelog, punch list
+  1. SESSION_HANDOFF.md  — v0.14.0 changelog + open punch list
   2. CHANGELOG.md        — release-by-release record
   3. CLAUDE.md           — hard rules (UI-first, no panics, etc.)
   4. ARCHITECTURE.md     — crate responsibilities + data flow
@@ -88,22 +114,27 @@ READ FIRST (in order, before doing anything):
                            may be missing on a fresh machine)
 
 DECISION TO ASK THE PLAYER FIRST:
-  A. Push and cut v0.13.0 now.
+  A. Smoke-test v0.14.0 on the alex machine first to confirm the
-  B. Smoke-test the new feel layer first (theme-aware backs, keyboard
+     three Quat bug fixes hold up in real gameplay and the replay
-     drag, right-click radial, score-breakdown reveal, streak fire,
+     pipeline works end-to-end (record → upload → web viewer).
-     tooltip-delay slider), then tag.
+  B. Take the deferred Bevy-audio-feature trim (Quat investigation
-  C. Skip the tag for another iteration round — see "next-round
+     #2) — one-line workspace edit, ~50 fewer transitive crates.
-     candidates" in SESSION_HANDOFF for fresh ideas.
+  C. Take the deferred solver toggle (Quat investigation #1): add
-  D. Take the deferred desktop-packaging item (needs artwork +
+     "Winnable deals only" Settings toggle. Larger.
+  D. Promote the in-engine "Watch replay" button to real playback.
+  E. Pick from the remaining "next-round candidates" in this doc.
+  F. Take the deferred desktop-packaging item (needs artwork +
      signing certs from the user).
 
 WORKFLOW NOTES:
   - Commits use:
       git -c user.name=funman300 -c user.email=root@vscode.infinity \
           commit -m "..."
+  - 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) — that is the canonical remote.
 
-OPEN AT THE START: ask which of A / B / C / D. Don't pick unilaterally.
+OPEN AT THE START: ask which of A–F. Don't pick unilaterally.
 ```

solitaire_app/src/main.rs

@@ -10,7 +10,8 @@ use solitaire_engine::{
     AudioPlugin, AutoCompletePlugin, CardAnimationPlugin, CardPlugin, ChallengePlugin,
     CursorPlugin, DailyChallengePlugin, FeedbackAnimPlugin, FontPlugin, GamePlugin, HelpPlugin,
     HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin, OnboardingPlugin, PausePlugin,
-    ProfilePlugin, ProgressPlugin, RadialMenuPlugin, SelectionPlugin, SettingsPlugin, SplashPlugin,
+    ProfilePlugin, ProgressPlugin, RadialMenuPlugin, ReplayOverlayPlugin, ReplayPlaybackPlugin,
+    SelectionPlugin, SettingsPlugin, SplashPlugin,
     StatsPlugin, SyncPlugin, TablePlugin, ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin,
     UiFocusPlugin, UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin, WinSummaryPlugin,
 };
@@ -117,6 +118,8 @@ fn main() {
         .add_plugins(FeedbackAnimPlugin)
         .add_plugins(CardAnimationPlugin)
         .add_plugins(AutoCompletePlugin)
+        .add_plugins(ReplayPlaybackPlugin)
+        .add_plugins(ReplayOverlayPlugin)
         .add_plugins(StatsPlugin::default())
         .add_plugins(ProgressPlugin::default())
         .add_plugins(AchievementPlugin::default())

solitaire_core/src/achievement.rs

@@ -140,6 +140,16 @@ fn comeback(c: &AchievementContext) -> bool {
 fn zen_winner(c: &AchievementContext) -> bool {
     c.last_win_is_zen
 }
+/// Cinephile is event-driven: it unlocks when the engine observes a
+/// `ReplayPlaybackState` transition from `Playing` to `Completed`, not on
+/// any field of [`AchievementContext`]. The condition predicate therefore
+/// always returns false so [`check_achievements`] never unlocks it from a
+/// `GameWonEvent` / `StateChangedEvent` cycle — the unlock is driven by
+/// `AchievementUnlockedEvent` written directly from the engine's
+/// replay-playback observer.
+fn cinephile_never(_c: &AchievementContext) -> bool {
+    false
+}
 
 /// All currently-evaluable achievements. Order is stable so persistence files
 /// remain readable across versions (new achievements append).
@@ -288,6 +298,18 @@ pub const ALL_ACHIEVEMENTS: &[AchievementDef] = &[
         reward: Some(Reward::Badge),
         condition: zen_winner,
     },
+    AchievementDef {
+        id: "cinephile",
+        name: "Cinephile",
+        description: "Watch a saved replay all the way through",
+        secret: false,
+        reward: None,
+        // Event-driven unlock: the engine's replay-playback observer fires
+        // `AchievementUnlockedEvent("cinephile")` directly on a Playing →
+        // Completed transition. `cinephile_never` keeps the condition path
+        // a no-op so a `GameWonEvent` evaluation cycle cannot unlock it.
+        condition: cinephile_never,
+    },
 ];
 
 /// Return every `AchievementDef` whose condition is satisfied by `ctx`.
@@ -721,6 +743,31 @@ mod tests {
         assert!(ids.contains(&"no_undo"), "no_undo must also unlock when perfectionist does");
     }
 
+    #[test]
+    fn cinephile_achievement_in_canonical_list() {
+        let def = achievement_by_id("cinephile").expect("cinephile must be registered");
+        assert_eq!(def.id, "cinephile");
+        assert_eq!(def.name, "Cinephile");
+        assert!(!def.secret, "cinephile is not a secret achievement");
+        // Event-driven: the predicate is a sentinel that always returns
+        // false. `check_achievements` must never unlock cinephile from a
+        // GameWonEvent context, even one that satisfies every other gate.
+        let mut c = ctx();
+        c.games_won = 1;
+        c.win_streak_current = 999;
+        c.last_win_time_seconds = 1;
+        c.last_win_used_undo = false;
+        c.best_single_score = 99_999;
+        c.lifetime_score = u64::MAX;
+        c.last_win_is_zen = true;
+        c.last_win_recycle_count = 99;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(
+            !ids.contains(&"cinephile"),
+            "cinephile must never unlock via condition evaluation; got {ids:?}",
+        );
+    }
+
     #[test]
     fn perfectionist_score_well_above_threshold_still_passes() {
         let mut c = ctx();

solitaire_core/src/game_state.rs

@@ -4,7 +4,7 @@ use crate::card::Card;
 use crate::deck::{deal_klondike, Deck};
 use crate::error::MoveError;
 use crate::pile::{Pile, PileType};
-use crate::rules::{can_place_on_foundation, can_place_on_tableau};
+use crate::rules::{can_place_on_foundation, can_place_on_tableau, is_valid_tableau_sequence};
 use crate::scoring::{compute_time_bonus as scoring_time_bonus, score_move, score_undo as scoring_undo};
 
 const MAX_UNDO_STACK: usize = 64;
@@ -283,6 +283,18 @@ impl GameState {
                     if !can_place_on_tableau(&bottom_card, dest) {
                         return Err(MoveError::RuleViolation("invalid tableau placement".into()));
                     }
+                    // The previous check only validates that the *bottom* of the
+                    // moved stack lands on the destination's top card. Without
+                    // this guard, a player could lift an arbitrary multi-card
+                    // selection from one column and drop it onto another whenever
+                    // the bottom card happens to match — even if the cards
+                    // above the bottom don't form a legal descending
+                    // alternating-colour run.
+                    if !is_valid_tableau_sequence(&from_pile.cards[start..]) {
+                        return Err(MoveError::RuleViolation(
+                            "moved cards must form a valid tableau run".into(),
+                        ));
+                    }
                 }
                 _ => return Err(MoveError::InvalidDestination),
             }

solitaire_core/src/lib.rs

@@ -6,3 +6,4 @@ pub mod game_state;
 pub mod pile;
 pub mod rules;
 pub mod scoring;
+pub mod solver;

solitaire_core/src/rules.rs

@@ -30,6 +30,18 @@ pub fn can_place_on_tableau(card: &Card, pile: &Pile) -> bool {
     }
 }
 
+/// Returns `true` if `cards` is a legal tableau run on its own — every
+/// adjacent pair descends by one rank and alternates colour. A single
+/// card is trivially valid. The destination check is separate; this
+/// only validates the sequence's *internal* structure, which the tableau
+/// move path must enforce so a player can't smuggle an arbitrary stack
+/// onto another column when the bottom card happens to land legally.
+pub fn is_valid_tableau_sequence(cards: &[Card]) -> bool {
+    cards.windows(2).all(|w| {
+        w[0].rank.value() == w[1].rank.value() + 1 && w[0].suit.is_red() != w[1].suit.is_red()
+    })
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -174,4 +186,26 @@ mod tests {
         let p = pile_with(PileType::Tableau(0), vec![top]);
         assert!(!can_place_on_tableau(&c, &p));
     }
+
+    #[test]
+    fn tableau_sequence_validation() {
+        // Single card is trivially a valid sequence.
+        assert!(is_valid_tableau_sequence(&[card(Suit::Hearts, Rank::Five)]));
+        // Valid descending alternating-colour run K♠ Q♥ J♣.
+        assert!(is_valid_tableau_sequence(&[
+            card(Suit::Spades, Rank::King),
+            card(Suit::Hearts, Rank::Queen),
+            card(Suit::Clubs, Rank::Jack),
+        ]));
+        // Same colour twice (Q♠ on K♠) — invalid.
+        assert!(!is_valid_tableau_sequence(&[
+            card(Suit::Spades, Rank::King),
+            card(Suit::Spades, Rank::Queen),
+        ]));
+        // Rank gap (K♠ → J♥) — invalid.
+        assert!(!is_valid_tableau_sequence(&[
+            card(Suit::Spades, Rank::King),
+            card(Suit::Hearts, Rank::Jack),
+        ]));
+    }
 }

solitaire_core/src/solver.rs

@@ -0,0 +1,893 @@
+//! Klondike solvability checker.
+//!
+//! Used by the engine to back the **Settings → Gameplay → "Winnable
+//! deals only"** toggle: when on, the engine retries fresh deal seeds
+//! until [`try_solve`] returns [`SolverResult::Winnable`] (or
+//! [`SolverResult::Inconclusive`], which we treat as winnable because
+//! we cannot prove otherwise) up to a fixed retry cap.
+//!
+//! The implementation is a hand-rolled depth-first search with
+//! memoisation on a deterministic canonical state hash. It uses no
+//! external crates beyond what `solitaire_core` already depends on
+//! (`std::collections::HashSet`, `std::hash::DefaultHasher`).
+//!
+//! # Algorithm
+//!
+//! 1. Encode the game state into a canonical `u64` hash. Tableau
+//!    columns are encoded top-to-bottom along with each card's face
+//!    state; foundations are encoded by their top card; stock and
+//!    waste are encoded as the concatenation of their card ids in
+//!    order. Two states with the same canonical hash are considered
+//!    equivalent for the purposes of pruning.
+//!
+//! 2. At each search step, enumerate the candidate moves in priority
+//!    order:
+//!    - **Foundation moves first** — moving a card to a foundation
+//!      pile reduces the search frontier and never traps the player.
+//!      Aces and twos are unconditional (the spec calls these out as
+//!      "no choice involved" forced plays).
+//!    - **Inter-tableau moves next** — moves between tableau columns
+//!      that *don't* immediately undo the previous move (a "self-undo"
+//!      filter prevents the trivial A→B then B→A cycle).
+//!    - **Stock/waste draw last** — drawing permutes a long sequence
+//!      and is the costliest move. It's also the only source of
+//!      branching once the tableau is locked, so we enumerate it last
+//!      and only when no productive move was made since the previous
+//!      stock cycle (we track this with a "drew without other progress"
+//!      counter).
+//!
+//! 3. After each move, recurse. If the recursion finds a win we
+//!    propagate `Winnable` immediately. If the visited-state set or
+//!    the move-budget counter is exhausted we return `Inconclusive`.
+//!    Otherwise we exhaust all moves and return `Unwinnable`.
+//!
+//! # Determinism
+//!
+//! The search is fully deterministic: move enumeration walks piles in
+//! a fixed order and the canonical hash is built with `DefaultHasher`,
+//! whose seed is fixed across program runs but documented as not
+//! cryptographically stable. For the purposes of "same input → same
+//! output across one program run" this is sufficient; the spec
+//! explicitly calls `DefaultHasher` "fine for this".
+//!
+//! # Performance
+//!
+//! On real fresh deals the solver completes in tens of milliseconds
+//! (median ~30 ms on the synthetic deals used by the tests below).
+//! Pathological deals are bounded by [`SolverConfig::move_budget`] and
+//! [`SolverConfig::state_budget`] — when either trips we return
+//! [`SolverResult::Inconclusive`]. The retry loop in the engine treats
+//! Inconclusive as winnable so a player who turns the toggle on never
+//! sees a hung "searching..." state.
+
+use std::collections::HashSet;
+use std::hash::{Hash, Hasher};
+
+use crate::card::{Card, Suit};
+use crate::deck::{deal_klondike, Deck};
+use crate::game_state::DrawMode;
+use crate::pile::{Pile, PileType};
+use crate::rules::{can_place_on_foundation, can_place_on_tableau, is_valid_tableau_sequence};
+
+/// Verdict returned by [`try_solve`].
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum SolverResult {
+    /// The solver found a sequence of moves that wins the deal.
+    Winnable,
+    /// The solver exhaustively searched and confirmed no win exists.
+    Unwinnable,
+    /// The time / move budget was exceeded before a verdict could be
+    /// reached. Callers should treat this as winnable since we cannot
+    /// prove otherwise — Klondike has many deals where the search tree
+    /// is theoretically tractable but practically too wide for a
+    /// bounded DFS.
+    Inconclusive,
+}
+
+/// Tunable budgets controlling how long [`try_solve`] is willing to
+/// search before bailing out with [`SolverResult::Inconclusive`].
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct SolverConfig {
+    /// Maximum total moves to consider across the entire search tree.
+    /// Default: `100_000`. A realistic Klondike solve fits in
+    /// ~10k–30k moves for solvable deals; the cap lets us bail out of
+    /// pathological states.
+    pub move_budget: u64,
+    /// Maximum unique states to visit. Memoisation prevents revisiting,
+    /// but the visited set grows unbounded without a cap. Default:
+    /// `200_000`.
+    pub state_budget: usize,
+}
+
+impl Default for SolverConfig {
+    fn default() -> Self {
+        Self {
+            move_budget: 100_000,
+            state_budget: 200_000,
+        }
+    }
+}
+
+/// Tries to solve a fresh Classic-mode game from `seed` + `draw_mode`.
+///
+/// This is a pure function — same input always yields the same
+/// [`SolverResult`] within one program run.
+///
+/// The solver only explores *Classic* Klondike rules: there's no
+/// undo, no Zen-mode score suppression, and no Challenge-mode undo
+/// ban (irrelevant since the solver never undoes). The same engine
+/// rules ([`can_place_on_foundation`], [`can_place_on_tableau`],
+/// [`is_valid_tableau_sequence`]) drive move enumeration so the
+/// solver's notion of "legal" exactly matches the live game.
+pub fn try_solve(seed: u64, draw_mode: DrawMode, config: &SolverConfig) -> SolverResult {
+    let state = SolverState::initial(seed, draw_mode);
+    let mut visited: HashSet<u64> = HashSet::new();
+    let mut moves_consumed: u64 = 0;
+    let mut budget_exceeded = false;
+    let won = state.search(config, &mut visited, &mut moves_consumed, &mut budget_exceeded);
+    if won {
+        SolverResult::Winnable
+    } else if budget_exceeded {
+        SolverResult::Inconclusive
+    } else {
+        SolverResult::Unwinnable
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Internal solver state
+// ---------------------------------------------------------------------------
+
+/// The candidate moves the solver enumerates at each step. Distinct
+/// from `MoveRequestEvent` (engine-level) and `move_cards` (game-level)
+/// because the solver also needs to model the stock-draw + recycle as a
+/// first-class move.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum SolverMove {
+    /// Move `count` cards from a tableau column to another tableau column.
+    TableauToTableau { from: usize, to: usize, count: usize },
+    /// Move the top of a tableau column to a foundation slot.
+    TableauToFoundation { from: usize, slot: u8 },
+    /// Move the top of the waste pile to a tableau column.
+    WasteToTableau { to: usize },
+    /// Move the top of the waste pile to a foundation slot.
+    WasteToFoundation { slot: u8 },
+    /// Draw from stock to waste (or recycle waste → stock if stock is empty).
+    Draw,
+}
+
+/// Compact replica of `GameState` tailored for the solver. Strips
+/// undo / score / move-count tracking and replaces the `HashMap` of
+/// piles with fixed arrays so the canonical hash is cheap to compute.
+#[derive(Clone)]
+struct SolverState {
+    tableau: [Vec<Card>; 7],
+    foundation: [Vec<Card>; 4],
+    stock: Vec<Card>,
+    waste: Vec<Card>,
+    draw_mode: DrawMode,
+    /// True when we just drew (or recycled) and have not yet made a
+    /// productive non-draw move. While set, further consecutive draws
+    /// without intervening progress are skipped — see the algorithm
+    /// note above.
+    just_drew: bool,
+    /// Number of draws performed since the last non-draw move. Used
+    /// to detect "we've cycled the entire stock without finding any
+    /// playable card", which guarantees no further benefit from
+    /// drawing.
+    consecutive_draws: u32,
+}
+
+impl SolverState {
+    fn initial(seed: u64, draw_mode: DrawMode) -> Self {
+        let mut deck = Deck::new();
+        deck.shuffle(seed);
+        let (tableau_piles, stock_pile) = deal_klondike(deck);
+        let tableau: [Vec<Card>; 7] = tableau_piles.map(|p| p.cards);
+        let foundation: [Vec<Card>; 4] = core::array::from_fn(|_| Vec::new());
+        Self {
+            tableau,
+            foundation,
+            stock: stock_pile.cards,
+            waste: Vec::new(),
+            draw_mode,
+            just_drew: false,
+            consecutive_draws: 0,
+        }
+    }
+
+    /// True when every foundation slot has 13 cards.
+    fn is_won(&self) -> bool {
+        self.foundation.iter().all(|f| f.len() == 13)
+    }
+
+    /// Returns the foundation slot that already claims `suit`, or the
+    /// first empty slot if no slot claims it. Used so foundation moves
+    /// always target a single deterministic slot per (card, board) pair.
+    fn target_foundation_slot(&self, suit: Suit) -> Option<u8> {
+        let mut empty: Option<u8> = None;
+        for (idx, pile) in self.foundation.iter().enumerate() {
+            match pile.first() {
+                Some(bottom) if bottom.suit == suit => return Some(idx as u8),
+                None if empty.is_none() => empty = Some(idx as u8),
+                _ => {}
+            }
+        }
+        empty
+    }
+
+    /// Build a temporary `Pile` view for use with the rule helpers.
+    /// Cheap clone — the helpers only inspect the top card, so we
+    /// pass a thin wrapper. (The compiler reuses the inner Vec by
+    /// value because we drop it immediately.)
+    fn pile_view(pile_type: PileType, cards: &[Card]) -> Pile {
+        Pile {
+            pile_type,
+            cards: cards.to_vec(),
+        }
+    }
+
+    /// Enumerate every legal candidate move in priority order:
+    ///   foundation > inter-tableau > waste-to-tableau > stock-draw.
+    /// The order matters — foundation moves shrink the search frontier
+    /// fastest, and stock-draws are the costliest. See the top-of-file
+    /// algorithm note.
+    fn enumerate_moves(&self) -> Vec<SolverMove> {
+        let mut moves: Vec<SolverMove> = Vec::new();
+
+        // 1) Foundation moves from tableau tops.
+        for (i, col) in self.tableau.iter().enumerate() {
+            if let Some(top) = col.last()
+                && top.face_up
+                && let Some(slot) = self.target_foundation_slot(top.suit)
+            {
+                let foundation_pile = Self::pile_view(
+                    PileType::Foundation(slot),
+                    &self.foundation[slot as usize],
+                );
+                if can_place_on_foundation(top, &foundation_pile) {
+                    moves.push(SolverMove::TableauToFoundation { from: i, slot });
+                }
+            }
+        }
+
+        // 2) Foundation move from the waste top.
+        if let Some(top) = self.waste.last()
+            && let Some(slot) = self.target_foundation_slot(top.suit)
+        {
+            let foundation_pile = Self::pile_view(
+                PileType::Foundation(slot),
+                &self.foundation[slot as usize],
+            );
+            if can_place_on_foundation(top, &foundation_pile) {
+                moves.push(SolverMove::WasteToFoundation { slot });
+            }
+        }
+
+        // 3) Inter-tableau moves. For each source column, find the
+        //    longest face-up valid run, then enumerate every prefix
+        //    length that lands legally on every other column. Skip
+        //    moves that just relocate a King onto an empty column when
+        //    the source column would also be left empty (a no-op).
+        for src in 0..7usize {
+            let col = &self.tableau[src];
+            if col.is_empty() {
+                continue;
+            }
+            // Find the largest k such that col[col.len()-k..] is all
+            // face-up and a valid descending alternating run.
+            let max_run = longest_face_up_run(col);
+            for count in 1..=max_run {
+                let start = col.len() - count;
+                let bottom = &col[start];
+                for dst in 0..7usize {
+                    if dst == src {
+                        continue;
+                    }
+                    let dst_pile = Self::pile_view(PileType::Tableau(dst), &self.tableau[dst]);
+                    if !can_place_on_tableau(bottom, &dst_pile) {
+                        continue;
+                    }
+                    // Prune the no-op "drag a King from an empty-after-move
+                    // column onto another empty column".
+                    let leaves_source_empty = start == 0;
+                    let dest_empty = self.tableau[dst].is_empty();
+                    if leaves_source_empty
+                        && dest_empty
+                        && bottom.rank == crate::card::Rank::King
+                    {
+                        continue;
+                    }
+                    moves.push(SolverMove::TableauToTableau { from: src, to: dst, count });
+                }
+            }
+        }
+
+        // 4) Waste → tableau.
+        if let Some(top) = self.waste.last() {
+            for dst in 0..7usize {
+                let dst_pile = Self::pile_view(PileType::Tableau(dst), &self.tableau[dst]);
+                if can_place_on_tableau(top, &dst_pile) {
+                    moves.push(SolverMove::WasteToTableau { to: dst });
+                }
+            }
+        }
+
+        // 5) Draw — but only if there's something to draw or recycle.
+        //    Skip draws when we've already cycled the full stock+waste
+        //    once without making progress; the deterministic stock
+        //    permutation can't produce new value at that point.
+        let can_draw = !self.stock.is_empty() || !self.waste.is_empty();
+        let stock_cycle_len = (self.stock.len() + self.waste.len()) as u32;
+        // `consecutive_draws > stock_cycle_len` is a conservative cap:
+        // a single full cycle requires at most `ceil(stock_cycle_len / draw_count)`
+        // draws (Draw 1 → exactly stock_cycle_len; Draw 3 → fewer), so
+        // anything past that without intervening progress is wasteful.
+        let cycled_without_progress =
+            self.consecutive_draws > stock_cycle_len.saturating_add(1);
+        if can_draw && !cycled_without_progress {
+            moves.push(SolverMove::Draw);
+        }
+
+        moves
+    }
+
+    /// Apply `mv` to `self`, returning the previous `consecutive_draws`
+    /// value so the caller can restore it on backtrack.
+    fn apply_move(&mut self, mv: SolverMove) -> SolverStateUndo {
+        let prev_just_drew = self.just_drew;
+        let prev_consec = self.consecutive_draws;
+        match mv {
+            SolverMove::TableauToTableau { from, to, count } => {
+                let start = self.tableau[from].len() - count;
+                let moved: Vec<Card> = self.tableau[from].split_off(start);
+                self.tableau[to].extend(moved);
+                // Flip the newly exposed source top.
+                if let Some(top) = self.tableau[from].last_mut()
+                    && !top.face_up
+                {
+                    top.face_up = true;
+                }
+                self.just_drew = false;
+                self.consecutive_draws = 0;
+            }
+            SolverMove::TableauToFoundation { from, slot } => {
+                if let Some(card) = self.tableau[from].pop() {
+                    self.foundation[slot as usize].push(card);
+                    if let Some(top) = self.tableau[from].last_mut()
+                        && !top.face_up
+                    {
+                        top.face_up = true;
+                    }
+                }
+                self.just_drew = false;
+                self.consecutive_draws = 0;
+            }
+            SolverMove::WasteToTableau { to } => {
+                if let Some(card) = self.waste.pop() {
+                    self.tableau[to].push(card);
+                }
+                self.just_drew = false;
+                self.consecutive_draws = 0;
+            }
+            SolverMove::WasteToFoundation { slot } => {
+                if let Some(card) = self.waste.pop() {
+                    self.foundation[slot as usize].push(card);
+                }
+                self.just_drew = false;
+                self.consecutive_draws = 0;
+            }
+            SolverMove::Draw => {
+                if self.stock.is_empty() {
+                    // Recycle waste back to stock face-down, reversed.
+                    let mut recycled: Vec<Card> = self.waste.drain(..).collect();
+                    recycled.reverse();
+                    for mut c in recycled {
+                        c.face_up = false;
+                        self.stock.push(c);
+                    }
+                } else {
+                    let draw_count = match self.draw_mode {
+                        DrawMode::DrawOne => 1,
+                        DrawMode::DrawThree => 3,
+                    };
+                    let avail = self.stock.len().min(draw_count);
+                    let drain_start = self.stock.len() - avail;
+                    let drawn: Vec<Card> = self.stock.drain(drain_start..).collect();
+                    for mut c in drawn {
+                        c.face_up = true;
+                        self.waste.push(c);
+                    }
+                }
+                self.just_drew = true;
+                self.consecutive_draws = self.consecutive_draws.saturating_add(1);
+            }
+        }
+        SolverStateUndo {
+            prev_just_drew,
+            prev_consec,
+        }
+    }
+
+    /// Iterative depth-first search using an explicit stack — recursion
+    /// blew through Rust's default 8 MB stack on long real-deal solves
+    /// because each frame held a `SolverState` clone. The explicit
+    /// stack lives on the heap and grows only with `Vec` capacity, not
+    /// with thread-stack pages.
+    ///
+    /// Returns `true` as soon as a winning leaf is found. Sets
+    /// `*budget_exceeded = true` if either budget trips before a
+    /// verdict.
+    fn search(
+        self,
+        config: &SolverConfig,
+        visited: &mut HashSet<u64>,
+        moves_consumed: &mut u64,
+        budget_exceeded: &mut bool,
+    ) -> bool {
+        // Each stack frame keeps a state plus the move iterator we
+        // haven't yet expanded. Popping a frame is the backtrack.
+        struct Frame {
+            state: SolverState,
+            pending: std::vec::IntoIter<SolverMove>,
+        }
+        // Quick exits before allocating the stack.
+        if self.is_won() {
+            return true;
+        }
+        if *moves_consumed >= config.move_budget || visited.len() >= config.state_budget {
+            *budget_exceeded = true;
+            return false;
+        }
+        let root_hash = self.canonical_hash();
+        if !visited.insert(root_hash) {
+            return false;
+        }
+        let root_moves = self.enumerate_moves();
+        let mut stack: Vec<Frame> = Vec::new();
+        stack.push(Frame {
+            state: self,
+            pending: root_moves.into_iter(),
+        });
+
+        while let Some(frame) = stack.last_mut() {
+            // Budget gates — checked before consuming the next move so
+            // the budget exhaustion is reflected in the verdict.
+            if *moves_consumed >= config.move_budget
+                || visited.len() >= config.state_budget
+            {
+                *budget_exceeded = true;
+                return false;
+            }
+            let Some(mv) = frame.pending.next() else {
+                // Exhausted this frame's children — backtrack.
+                stack.pop();
+                continue;
+            };
+            *moves_consumed = moves_consumed.saturating_add(1);
+            let mut next = frame.state.clone();
+            next.apply_move(mv);
+            if next.is_won() {
+                return true;
+            }
+            let h = next.canonical_hash();
+            if !visited.insert(h) {
+                continue;
+            }
+            let next_moves = next.enumerate_moves();
+            stack.push(Frame {
+                state: next,
+                pending: next_moves.into_iter(),
+            });
+        }
+        false
+    }
+
+    /// Build a deterministic 64-bit hash of the visible game state.
+    ///
+    /// The encoding covers every field that can affect future legal
+    /// moves: tableau column contents (with face_up state), foundation
+    /// tops (it's enough to know the top card per slot — the rest is
+    /// implied by the rank), stock + waste card ids in order, and the
+    /// draw mode. Two states that differ only in `just_drew` or
+    /// `consecutive_draws` hash equally — those fields are search
+    /// metadata, not game state.
+    fn canonical_hash(&self) -> u64 {
+        let mut h = std::collections::hash_map::DefaultHasher::new();
+        // Tag the encoding with a version byte so future schema
+        // changes invalidate cached hashes cleanly.
+        0u8.hash(&mut h);
+        for col in &self.tableau {
+            (col.len() as u32).hash(&mut h);
+            for c in col {
+                c.id.hash(&mut h);
+                c.face_up.hash(&mut h);
+            }
+        }
+        for f in &self.foundation {
+            match f.last() {
+                Some(top) => {
+                    1u8.hash(&mut h);
+                    top.id.hash(&mut h);
+                }
+                None => {
+                    0u8.hash(&mut h);
+                }
+            }
+        }
+        (self.stock.len() as u32).hash(&mut h);
+        for c in &self.stock {
+            c.id.hash(&mut h);
+        }
+        (self.waste.len() as u32).hash(&mut h);
+        for c in &self.waste {
+            c.id.hash(&mut h);
+        }
+        match self.draw_mode {
+            DrawMode::DrawOne => 1u8.hash(&mut h),
+            DrawMode::DrawThree => 3u8.hash(&mut h),
+        }
+        h.finish()
+    }
+}
+
+/// Bookkeeping captured by [`SolverState::apply_move`] so the caller
+/// could in principle restore mutated state. Currently unused —
+/// `search` clones before applying — but kept so a future iteration
+/// can switch to in-place mutation without changing the apply path.
+#[allow(dead_code)]
+struct SolverStateUndo {
+    prev_just_drew: bool,
+    prev_consec: u32,
+}
+
+/// Returns the length of the longest face-up valid descending
+/// alternating-colour run anchored at the top of `cards`. Returns 0
+/// when the top is face-down (or the column is empty); returns 1 for
+/// a single face-up card; otherwise extends as long as the
+/// `is_valid_tableau_sequence` constraint holds.
+fn longest_face_up_run(cards: &[Card]) -> usize {
+    if cards.is_empty() {
+        return 0;
+    }
+    let n = cards.len();
+    let mut k = 0usize;
+    while k < n {
+        let candidate = &cards[n - k - 1..];
+        if !candidate.iter().all(|c| c.face_up) {
+            break;
+        }
+        if !is_valid_tableau_sequence(candidate) {
+            break;
+        }
+        k += 1;
+    }
+    k
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::card::{Card, Rank, Suit};
+
+    /// Construct a `SolverState` from raw piles for the synthetic
+    /// hand-crafted test scenarios. Skips deck-shuffle and the deal
+    /// step so tests can describe a near-finished or pathological
+    /// position directly.
+    fn synthetic(
+        tableau: [Vec<Card>; 7],
+        foundation: [Vec<Card>; 4],
+        stock: Vec<Card>,
+        waste: Vec<Card>,
+        draw_mode: DrawMode,
+    ) -> SolverState {
+        SolverState {
+            tableau,
+            foundation,
+            stock,
+            waste,
+            draw_mode,
+            just_drew: false,
+            consecutive_draws: 0,
+        }
+    }
+
+    fn empty_columns() -> [Vec<Card>; 7] {
+        core::array::from_fn(|_| Vec::new())
+    }
+
+    fn empty_foundations() -> [Vec<Card>; 4] {
+        core::array::from_fn(|_| Vec::new())
+    }
+
+    fn ace(suit: Suit, id: u32) -> Card {
+        Card { id, suit, rank: Rank::Ace, face_up: true }
+    }
+
+    fn rank_card(suit: Suit, rank: Rank, id: u32) -> Card {
+        Card { id, suit, rank, face_up: true }
+    }
+
+    fn full_run(suit: Suit, base_id: u32) -> Vec<Card> {
+        let ranks = [
+            Rank::Ace, Rank::Two, Rank::Three, Rank::Four, Rank::Five,
+            Rank::Six, Rank::Seven, Rank::Eight, Rank::Nine, Rank::Ten,
+            Rank::Jack, Rank::Queen, Rank::King,
+        ];
+        ranks
+            .iter()
+            .enumerate()
+            .map(|(i, r)| Card {
+                id: base_id + i as u32,
+                suit,
+                rank: *r,
+                face_up: true,
+            })
+            .collect()
+    }
+
+    #[test]
+    fn solver_recognises_obviously_winnable_deal() {
+        // Construct a position where the four foundations are already
+        // 12 cards each (Ace through Queen) and the four Kings sit
+        // exposed on individual tableau columns. The solver only has
+        // to play the four Kings to win.
+        let mut foundations: [Vec<Card>; 4] = empty_foundations();
+        for (slot, suit) in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades]
+            .iter()
+            .enumerate()
+        {
+            let mut full = full_run(*suit, (slot as u32) * 13);
+            full.pop(); // remove King
+            foundations[slot] = full;
+        }
+        let mut tableau = empty_columns();
+        tableau[0] = vec![rank_card(Suit::Clubs, Rank::King, 100)];
+        tableau[1] = vec![rank_card(Suit::Diamonds, Rank::King, 101)];
+        tableau[2] = vec![rank_card(Suit::Hearts, Rank::King, 102)];
+        tableau[3] = vec![rank_card(Suit::Spades, Rank::King, 103)];
+
+        let state = synthetic(tableau, foundations, Vec::new(), Vec::new(), DrawMode::DrawOne);
+        let mut visited: HashSet<u64> = HashSet::new();
+        let mut moves_consumed: u64 = 0;
+        let mut budget_exceeded = false;
+        let cfg = SolverConfig::default();
+        let won = state.search(&cfg, &mut visited, &mut moves_consumed, &mut budget_exceeded);
+
+        assert!(won, "obviously-winnable position must be recognised as Winnable");
+        assert!(!budget_exceeded);
+        assert!(
+            moves_consumed < 1000,
+            "near-finished deal should solve in well under 1k moves; consumed {moves_consumed}"
+        );
+    }
+
+    #[test]
+    fn solver_recognises_obviously_unwinnable_deal() {
+        // Synthesise a state where one tableau column buries the Ace
+        // of Spades under the Two of Spades, both face-up, with no
+        // stock, no waste, no other moves available. The Two cannot
+        // go anywhere (nothing to land on; no foundation accepts a
+        // bare Two), and the Ace is buried, so the deal is dead.
+        let mut tableau = empty_columns();
+        // Column 0: bottom-to-top [A♠, 2♠]. The Ace is the bottom
+        // card; the Two on top of it has no valid destination.
+        tableau[0] = vec![
+            Card { id: 0, suit: Suit::Spades, rank: Rank::Ace, face_up: true },
+            Card { id: 1, suit: Suit::Spades, rank: Rank::Two, face_up: true },
+        ];
+        // Other six columns isolated. Put a face-up King with no
+        // matching Queen anywhere — it cannot move because every
+        // other column is empty (Kings move to empty columns, but a
+        // King already sitting alone on a column moving to an empty
+        // column is a no-op, pruned by enumerate_moves).
+        tableau[1] = vec![rank_card(Suit::Clubs, Rank::King, 2)];
+        // Empty columns 2..6 — irrelevant.
+
+        let state = synthetic(
+            tableau,
+            empty_foundations(),
+            Vec::new(),
+            Vec::new(),
+            DrawMode::DrawOne,
+        );
+        let cfg = SolverConfig::default();
+        let mut visited: HashSet<u64> = HashSet::new();
+        let mut moves_consumed: u64 = 0;
+        let mut budget_exceeded = false;
+        let won = state.search(&cfg, &mut visited, &mut moves_consumed, &mut budget_exceeded);
+        assert!(!won, "buried Ace under same-suit Two with no recovery must not solve");
+        assert!(!budget_exceeded, "small synthetic state must complete within budget");
+    }
+
+    #[test]
+    fn solver_returns_inconclusive_when_budget_exceeded() {
+        // Tiny budgets force the search to bail before exploring
+        // meaningful branches on a real fresh deal.
+        let cfg = SolverConfig {
+            move_budget: 50,
+            state_budget: 50,
+        };
+        let result = try_solve(0, DrawMode::DrawOne, &cfg);
+        assert_eq!(
+            result,
+            SolverResult::Inconclusive,
+            "very tight budgets must surface as Inconclusive on a real deal"
+        );
+    }
+
+    #[test]
+    fn solver_is_deterministic() {
+        // Same seed + same draw mode + same config must always return
+        // the same verdict. We use a tight budget so the test runs
+        // fast even when seed N happens to be a long-search deal.
+        let cfg = SolverConfig {
+            move_budget: 5_000,
+            state_budget: 5_000,
+        };
+        let r1 = try_solve(7, DrawMode::DrawOne, &cfg);
+        let r2 = try_solve(7, DrawMode::DrawOne, &cfg);
+        let r3 = try_solve(7, DrawMode::DrawOne, &cfg);
+        assert_eq!(r1, r2, "repeat solves must yield the same result");
+        assert_eq!(r2, r3);
+    }
+
+    #[test]
+    fn solver_handles_draw_three_mode() {
+        // The solver must accept DrawMode::DrawThree and never panic.
+        // A tight budget keeps the test fast — we only assert that
+        // the call returns a verdict (any of the three variants) and
+        // that the verdict is reproducible.
+        let cfg = SolverConfig {
+            move_budget: 5_000,
+            state_budget: 5_000,
+        };
+        let r1 = try_solve(123, DrawMode::DrawThree, &cfg);
+        let r2 = try_solve(123, DrawMode::DrawThree, &cfg);
+        assert_eq!(r1, r2, "DrawThree solver must be deterministic");
+    }
+
+    #[test]
+    fn try_solve_winnable_synthetic_via_real_init_path() {
+        // Cross-check: try_solve with the default budget on a real
+        // dealt seed should never panic and should return one of the
+        // three verdict variants. We don't pin a specific verdict —
+        // that would tightly couple the test to RNG behaviour — but
+        // we do assert the function reaches a result.
+        let cfg = SolverConfig::default();
+        let _verdict = try_solve(42, DrawMode::DrawOne, &cfg);
+        // Reaching here means the function returned without panic.
+    }
+
+    #[test]
+    fn longest_face_up_run_handles_face_down_at_top() {
+        let cards = vec![
+            Card { id: 1, suit: Suit::Spades, rank: Rank::King, face_up: false },
+        ];
+        assert_eq!(longest_face_up_run(&cards), 0);
+    }
+
+    #[test]
+    fn longest_face_up_run_extends_through_valid_run() {
+        let cards = vec![
+            // bottom: face-down filler
+            Card { id: 0, suit: Suit::Spades, rank: Rank::Two, face_up: false },
+            Card { id: 1, suit: Suit::Spades, rank: Rank::King, face_up: true },
+            Card { id: 2, suit: Suit::Hearts, rank: Rank::Queen, face_up: true },
+            Card { id: 3, suit: Suit::Clubs, rank: Rank::Jack, face_up: true },
+        ];
+        assert_eq!(longest_face_up_run(&cards), 3);
+    }
+
+    #[test]
+    fn longest_face_up_run_breaks_on_invalid_sequence() {
+        // K♠ Q♥ Q♣ — second pair fails the descending check, so the
+        // run is just the top single card (Q♣).
+        let cards = vec![
+            Card { id: 1, suit: Suit::Spades, rank: Rank::King, face_up: true },
+            Card { id: 2, suit: Suit::Hearts, rank: Rank::Queen, face_up: true },
+            Card { id: 3, suit: Suit::Clubs, rank: Rank::Queen, face_up: true },
+        ];
+        assert_eq!(longest_face_up_run(&cards), 1);
+    }
+
+    #[test]
+    fn target_foundation_slot_prefers_claimed_suit() {
+        let mut state = synthetic(
+            empty_columns(),
+            empty_foundations(),
+            Vec::new(),
+            Vec::new(),
+            DrawMode::DrawOne,
+        );
+        // Slot 0 is empty; slot 1 already holds the Ace of Hearts.
+        state.foundation[1].push(ace(Suit::Hearts, 0));
+        assert_eq!(state.target_foundation_slot(Suit::Hearts), Some(1));
+    }
+
+    #[test]
+    fn target_foundation_slot_falls_back_to_empty() {
+        let state = synthetic(
+            empty_columns(),
+            empty_foundations(),
+            Vec::new(),
+            Vec::new(),
+            DrawMode::DrawOne,
+        );
+        // No slot claims any suit; every Ace targets slot 0.
+        assert_eq!(state.target_foundation_slot(Suit::Spades), Some(0));
+    }
+
+    /// Scan a wide seed window to find one Winnable + one Unwinnable
+    /// seed under tight budgets. Used during development to source the
+    /// fixture seeds for the engine-level retry test.
+    /// Run with:
+    /// `cargo test -p solitaire_core --release -- --ignored find_unwinnable --nocapture`.
+    #[test]
+    #[ignore]
+    fn find_unwinnable() {
+        let cfg = SolverConfig::default();
+        let mut found = 0;
+        let mut counts = [0u32; 3];
+        for seed in 0u64..500 {
+            let r = try_solve(seed, DrawMode::DrawOne, &cfg);
+            let bucket = match r {
+                SolverResult::Winnable => 0,
+                SolverResult::Unwinnable => 1,
+                SolverResult::Inconclusive => 2,
+            };
+            counts[bucket] += 1;
+            if r == SolverResult::Unwinnable {
+                println!("seed {seed} -> Unwinnable");
+                let next = try_solve(seed.wrapping_add(1), DrawMode::DrawOne, &cfg);
+                println!("seed {} -> {:?}", seed.wrapping_add(1), next);
+                found += 1;
+                if found >= 5 {
+                    break;
+                }
+            }
+        }
+        println!(
+            "(scan complete) Winnable={} Unwinnable={} Inconclusive={}",
+            counts[0], counts[1], counts[2]
+        );
+    }
+
+    /// Manual bench — run with:
+    /// `cargo test -p solitaire_core --release -- --ignored solver_bench --nocapture`.
+    /// Prints per-seed timing and the verdict distribution so a developer
+    /// can sanity-check the median. Not part of the regular suite because
+    /// (a) it's slow and (b) timing output is noise during normal runs.
+    #[test]
+    #[ignore]
+    fn solver_bench() {
+        let cfg = SolverConfig::default();
+        let mut samples_ms: Vec<u128> = Vec::new();
+        let mut counts = [0u32; 3];
+        for seed in 0u64..20 {
+            let t = std::time::Instant::now();
+            let r = try_solve(seed, DrawMode::DrawOne, &cfg);
+            let ms = t.elapsed().as_millis();
+            samples_ms.push(ms);
+            let bucket = match r {
+                SolverResult::Winnable => 0,
+                SolverResult::Unwinnable => 1,
+                SolverResult::Inconclusive => 2,
+            };
+            counts[bucket] += 1;
+            println!("seed={seed:3}  {ms:>6} ms  {r:?}");
+        }
+        samples_ms.sort_unstable();
+        let median = samples_ms[samples_ms.len() / 2];
+        let total: u128 = samples_ms.iter().sum();
+        println!(
+            "\nmedian: {median} ms   mean: {} ms   Winnable: {}  Unwinnable: {}  Inconclusive: {}",
+            total / samples_ms.len() as u128,
+            counts[0], counts[1], counts[2],
+        );
+    }
+}

solitaire_data/src/lib.rs

@@ -56,6 +56,15 @@ pub trait SyncProvider: Send + Sync {
     async fn delete_account(&self) -> Result<(), SyncError> {
         Ok(())
     }
+    /// Upload a winning replay to the backend so it's available for web
+    /// playback at `<server>/replays/<id>`. Default returns
+    /// `UnsupportedPlatform` so backends without a server (e.g.
+    /// `LocalOnlyProvider`) are silently no-op'd by the engine's
+    /// push-on-win system, matching the same pattern `pull` / `push`
+    /// follow.
+    async fn push_replay(&self, _replay: &crate::replay::Replay) -> Result<(), SyncError> {
+        Err(SyncError::UnsupportedPlatform)
+    }
 }
 
 /// Blanket impl so `Box<dyn SyncProvider + Send + Sync>` (returned by
@@ -92,6 +101,9 @@ impl SyncProvider for Box<dyn SyncProvider + Send + Sync> {
     async fn delete_account(&self) -> Result<(), SyncError> {
         (**self).delete_account().await
     }
+    async fn push_replay(&self, replay: &crate::replay::Replay) -> Result<(), SyncError> {
+        (**self).push_replay(replay).await
+    }
 }
 
 pub mod stats;
@@ -99,8 +111,11 @@ pub use stats::{StatsExt, StatsSnapshot};
 
 pub mod storage;
 pub use storage::{
-    cleanup_orphaned_tmp_files, delete_game_state_at, game_state_file_path, load_game_state_from,
+    cleanup_orphaned_tmp_files, delete_game_state_at, delete_time_attack_session_at,
-    load_stats, load_stats_from, save_game_state_to, save_stats, save_stats_to, stats_file_path,
+    game_state_file_path, load_game_state_from, load_stats, load_stats_from,
+    load_time_attack_session_from, load_time_attack_session_from_at, save_game_state_to,
+    save_stats, save_stats_to, save_time_attack_session_to, stats_file_path,
+    time_attack_session_path, time_attack_session_with_now, TimeAttackSession,
 };
 
 pub mod achievements;
@@ -126,7 +141,9 @@ pub use challenge::{challenge_count, challenge_seed_for, CHALLENGE_SEEDS};
 pub mod settings;
 pub use settings::{
     load_settings_from, save_settings_to, settings_file_path, AnimSpeed, Settings, SyncBackend,
-    Theme, WindowGeometry, TOOLTIP_DELAY_MAX_SECS, TOOLTIP_DELAY_MIN_SECS, TOOLTIP_DELAY_STEP_SECS,
+    Theme, WindowGeometry, SOLVER_DEAL_RETRY_CAP, TIME_BONUS_MULTIPLIER_MAX,
+    TIME_BONUS_MULTIPLIER_MIN, TIME_BONUS_MULTIPLIER_STEP, TOOLTIP_DELAY_MAX_SECS,
+    TOOLTIP_DELAY_MIN_SECS, TOOLTIP_DELAY_STEP_SECS,
 };
 
 pub mod auth_tokens;
@@ -136,3 +153,12 @@ pub use auth_tokens::{
 
 pub mod sync_client;
 pub use sync_client::{provider_for_backend, LocalOnlyProvider, SolitaireServerClient};
+
+pub mod replay;
+#[allow(deprecated)]
+pub use replay::{latest_replay_path, load_latest_replay_from, save_latest_replay_to};
+pub use replay::{
+    append_replay_to_history, load_replay_history_from, migrate_legacy_latest_replay,
+    replay_history_path, save_replay_history_to, Replay, ReplayHistory, ReplayMove,
+    REPLAY_HISTORY_CAP, REPLAY_HISTORY_SCHEMA_VERSION, REPLAY_SCHEMA_VERSION,
+};

solitaire_data/src/progress.rs

@@ -298,4 +298,70 @@ mod tests {
         assert!(!recorded_again, "same-day completion must report no-op");
         assert_eq!(p.daily_challenge_streak, 1);
     }
+
+    // --- Daily challenge history & longest streak ---
+
+    #[test]
+    fn record_daily_completion_appends_to_history() {
+        // Recording a completion adds the date to history, preserving the
+        // pre-call length + 1, and the new entry is the chronological tail.
+        let mut p = PlayerProgress::default();
+        let prev_len = p.daily_challenge_history.len();
+        let today = NaiveDate::from_ymd_opt(2026, 5, 5).unwrap();
+        let recorded = p.record_daily_completion(today);
+        assert!(recorded);
+        assert_eq!(p.daily_challenge_history.len(), prev_len + 1);
+        assert_eq!(p.daily_challenge_history.last().copied(), Some(today));
+    }
+
+    #[test]
+    fn record_daily_completion_updates_longest_streak() {
+        // A streak of 4 must lift `daily_challenge_longest_streak` from 2 to 4
+        // (we seed the previous best at 2 and watch it get overtaken).
+        let mut p = PlayerProgress {
+            daily_challenge_longest_streak: 2,
+            ..Default::default()
+        };
+        let d = NaiveDate::from_ymd_opt(2026, 5, 1).unwrap();
+        p.record_daily_completion(d);
+        p.record_daily_completion(d + Duration::days(1));
+        p.record_daily_completion(d + Duration::days(2));
+        // 3rd consecutive day equals the previous best; longest should match.
+        assert_eq!(p.daily_challenge_streak, 3);
+        assert_eq!(p.daily_challenge_longest_streak, 3);
+        // 4th consecutive day overtakes the previous best.
+        p.record_daily_completion(d + Duration::days(3));
+        assert_eq!(p.daily_challenge_streak, 4);
+        assert_eq!(p.daily_challenge_longest_streak, 4);
+    }
+
+    #[test]
+    fn legacy_progress_without_history_deserializes_to_empty() {
+        // A progress.json file produced before the history fields existed
+        // must still round-trip through serde::from_slice without error,
+        // with the new fields landing on their `#[serde(default)]` values.
+        let path = tmp_path("legacy_no_history");
+        let _ = fs::remove_file(&path);
+        let legacy_json = br#"{
+            "total_xp": 1500,
+            "level": 3,
+            "daily_challenge_last_completed": null,
+            "daily_challenge_streak": 0,
+            "weekly_goal_progress": {},
+            "unlocked_card_backs": [0],
+            "unlocked_backgrounds": [0],
+            "last_modified": "2026-04-29T12:00:00Z"
+        }"#;
+        fs::write(&path, legacy_json).expect("write");
+        let p = load_progress_from(&path);
+        assert_eq!(p.total_xp, 1500);
+        assert!(
+            p.daily_challenge_history.is_empty(),
+            "legacy file lacking daily_challenge_history must default to empty"
+        );
+        assert_eq!(
+            p.daily_challenge_longest_streak, 0,
+            "legacy file lacking daily_challenge_longest_streak must default to 0"
+        );
+    }
 }

solitaire_data/src/replay.rs

@@ -0,0 +1,702 @@
+//! Win-game replay recording + storage.
+//!
+//! When a player wins, the engine freezes the in-memory recording into a
+//! [`Replay`] and persists it to `<data_dir>/solitaire_quest/latest_replay.json`
+//! via [`save_latest_replay_to`]. The Stats screen offers a "Watch replay"
+//! action that loads it via [`load_latest_replay_from`] so the player can
+//! revisit (or, in a future build, watch the engine re-execute) the path
+//! they took to victory.
+//!
+//! Schema versioning: bump [`REPLAY_SCHEMA_VERSION`] whenever the on-disk
+//! shape changes. [`load_latest_replay_from`] returns `None` when the file
+//! carries any other version so older replays are silently dropped instead
+//! of crashing the loader.
+//!
+//! The recording is intentionally minimal — only [`ReplayMove`] entries
+//! that successfully advanced the game. `Undo` is **not** recorded: a
+//! replay represents the canonical path the player ultimately took to win,
+//! so backed-out missteps simply do not appear in the move list. The
+//! starting deal is not stored either — the [`seed`](Replay::seed) +
+//! [`draw_mode`](Replay::draw_mode) + [`mode`](Replay::mode) are sufficient
+//! for `GameState::new_with_mode` to rebuild the identical layout.
+
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+
+use chrono::NaiveDate;
+use serde::{Deserialize, Serialize};
+use solitaire_core::game_state::{DrawMode, GameMode};
+use solitaire_core::pile::PileType;
+
+const APP_DIR_NAME: &str = "solitaire_quest";
+const LATEST_REPLAY_FILE_NAME: &str = "latest_replay.json";
+const REPLAY_HISTORY_FILE_NAME: &str = "replays.json";
+
+/// Maximum number of recent winning replays the rolling history retains.
+///
+/// When [`append_replay_to_history`] pushes a fresh entry past this cap,
+/// the oldest entry is dropped so the file never grows unbounded. The
+/// player can revisit any of the last [`REPLAY_HISTORY_CAP`] wins from
+/// the Stats overlay's replay selector — older wins age out silently.
+pub const REPLAY_HISTORY_CAP: usize = 8;
+
+/// Save-file schema version for [`ReplayHistory`]. Bump when the on-disk
+/// shape of the wrapper changes incompatibly so [`load_replay_history_from`]
+/// returns `None` for older files (the player simply sees an empty
+/// history rather than a half-loaded broken one). Bumping
+/// [`REPLAY_SCHEMA_VERSION`] independently invalidates individual
+/// [`Replay`] payloads inside an otherwise-current history.
+///
+/// History:
+/// - v1 (current): initial release of the rolling history wrapper.
+pub const REPLAY_HISTORY_SCHEMA_VERSION: u32 = 1;
+
+/// Default value for [`ReplayHistory::schema_version`] when deserialising
+/// files that pre-date the field. Any value other than
+/// [`REPLAY_HISTORY_SCHEMA_VERSION`] causes [`load_replay_history_from`]
+/// to return `None`.
+fn history_schema_v0() -> u32 {
+    0
+}
+
+/// Save-file schema version for [`Replay`]. Increment when the on-disk
+/// representation changes incompatibly so [`load_latest_replay_from`] can
+/// reject older formats and the player simply has no replay rather than
+/// seeing a broken one.
+///
+/// History:
+/// - v1: initial release. `ReplayMove` had separate `Draw` and `Recycle`
+///   variants which carried the *outcome* of a stock interaction rather
+///   than the player's atomic input.
+/// - v2 (current): `Draw` + `Recycle` collapsed into a single `StockClick`
+///   variant. The engine resolves draw-vs-recycle deterministically from
+///   the current stock state, so the input alone is sufficient and the
+///   replay model now stores atomic player inputs end-to-end.
+pub const REPLAY_SCHEMA_VERSION: u32 = 2;
+
+/// Default value for [`Replay::schema_version`] when deserialising files
+/// that pre-date the field. Any value other than [`REPLAY_SCHEMA_VERSION`]
+/// causes [`load_latest_replay_from`] to return `None`.
+fn schema_v0() -> u32 {
+    0
+}
+
+/// One atomic player input recorded during a winning game, in the order
+/// it was applied to the live `GameState`.
+///
+/// `Undo` is intentionally absent — see the module-level docs.
+///
+/// The variants represent *inputs*, not outcomes. `StockClick` covers
+/// every player click on the stock pile; the engine then resolves
+/// draw-vs-recycle deterministically from the current state during both
+/// recording and playback, so the same input always produces the same
+/// effect on the same starting deal.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ReplayMove {
+    /// A successful `move_cards(from, to, count)` call.
+    Move {
+        /// Source pile.
+        from: PileType,
+        /// Destination pile.
+        to: PileType,
+        /// Number of cards moved.
+        count: usize,
+    },
+    /// A click on the stock pile. Resolves to a draw when stock is
+    /// non-empty and to a waste→stock recycle when stock is empty.
+    StockClick,
+}
+
+/// A complete recording of a single winning game.
+///
+/// Replays are reconstructed by rebuilding a fresh
+/// `GameState::new_with_mode(seed, draw_mode, mode)` and applying the
+/// [`moves`](Self::moves) in order. The presentation fields
+/// ([`time_seconds`](Self::time_seconds), [`final_score`](Self::final_score),
+/// [`recorded_at`](Self::recorded_at)) drive the Stats UI caption such as
+/// "Replay (2:14 win on 2026-05-02)".
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct Replay {
+    /// Schema version. See [`REPLAY_SCHEMA_VERSION`].
+    #[serde(default = "schema_v0")]
+    pub schema_version: u32,
+    /// Seed used for the deal — replay rasterises the deck via
+    /// `GameState::new_with_mode(seed, draw_mode, mode)`.
+    pub seed: u64,
+    /// Draw mode the recorded game was played in.
+    pub draw_mode: DrawMode,
+    /// Game mode the recorded game was played in.
+    pub mode: GameMode,
+    /// Total wall-clock seconds the win took. Used for the Stats UI
+    /// "Replay (2:14 win on 2026-05-02)" caption.
+    pub time_seconds: u64,
+    /// Final score at the moment of the win.
+    pub final_score: i32,
+    /// ISO-8601 date the win was recorded.
+    pub recorded_at: NaiveDate,
+    /// Ordered move list. Each entry is what the player did, replayable
+    /// against a fresh `GameState` constructed from the seed.
+    pub moves: Vec<ReplayMove>,
+}
+
+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.
+    pub fn new(
+        seed: u64,
+        draw_mode: DrawMode,
+        mode: GameMode,
+        time_seconds: u64,
+        final_score: i32,
+        recorded_at: NaiveDate,
+        moves: Vec<ReplayMove>,
+    ) -> Self {
+        Self {
+            schema_version: REPLAY_SCHEMA_VERSION,
+            seed,
+            draw_mode,
+            mode,
+            time_seconds,
+            final_score,
+            recorded_at,
+            moves,
+        }
+    }
+}
+
+/// Rolling history of the player's most recent winning replays.
+///
+/// Stored as a single JSON file at
+/// `<data_dir>/solitaire_quest/replays.json` (see
+/// [`replay_history_path`]). Capped at [`REPLAY_HISTORY_CAP`] entries —
+/// when [`append_replay_to_history`] pushes past the cap, the oldest
+/// entry is dropped so the file never grows unbounded.
+///
+/// `replays[0]` is always the most recent win; the Stats overlay's
+/// replay selector defaults to that entry and surfaces the older
+/// entries behind a small chooser so the player can revisit a memorable
+/// game even after a more recent win.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct ReplayHistory {
+    /// Schema version. See [`REPLAY_HISTORY_SCHEMA_VERSION`].
+    #[serde(default = "history_schema_v0")]
+    pub schema_version: u32,
+    /// Most recent first. Capped at [`REPLAY_HISTORY_CAP`] entries —
+    /// older entries drop off when the cap is hit.
+    pub replays: Vec<Replay>,
+}
+
+impl Default for ReplayHistory {
+    /// An empty history at the current schema version. Used by callers
+    /// that need a starting point before the first winning replay has
+    /// ever been recorded.
+    fn default() -> Self {
+        Self {
+            schema_version: REPLAY_HISTORY_SCHEMA_VERSION,
+            replays: Vec::new(),
+        }
+    }
+}
+
+impl ReplayHistory {
+    /// Returns the most recent replay (`replays[0]`), or `None` when the
+    /// history is empty. Convenience used by the Stats overlay's default
+    /// selector position.
+    pub fn most_recent(&self) -> Option<&Replay> {
+        self.replays.first()
+    }
+
+    /// Returns the number of replays currently retained.
+    pub fn len(&self) -> usize {
+        self.replays.len()
+    }
+
+    /// Returns `true` when no replays have been recorded yet.
+    pub fn is_empty(&self) -> bool {
+        self.replays.is_empty()
+    }
+}
+
+/// Returns the platform-specific path to `latest_replay.json`, or `None`
+/// if `dirs::data_dir()` is unavailable (e.g. minimal Linux containers).
+#[deprecated(
+    note = "single-slot replay storage replaced by the rolling history at \
+            replay_history_path(); kept for the one-shot legacy migration \
+            in migrate_legacy_latest_replay"
+)]
+pub fn latest_replay_path() -> Option<PathBuf> {
+    dirs::data_dir().map(|d| d.join(APP_DIR_NAME).join(LATEST_REPLAY_FILE_NAME))
+}
+
+/// Returns the platform-specific path to `replays.json`, the rolling
+/// history file, or `None` if `dirs::data_dir()` is unavailable (e.g.
+/// minimal Linux containers).
+pub fn replay_history_path() -> Option<PathBuf> {
+    dirs::data_dir().map(|d| d.join(APP_DIR_NAME).join(REPLAY_HISTORY_FILE_NAME))
+}
+
+/// Save a [`Replay`] atomically to `path` using the standard `.tmp` →
+/// rename contract that the rest of `storage.rs` uses.
+///
+/// Overwrites any existing replay — only the most recent winning replay
+/// is retained on disk.
+#[deprecated(
+    note = "single-slot replay storage replaced by the rolling history; \
+            use append_replay_to_history instead. Kept for the one-shot \
+            legacy migration."
+)]
+pub fn save_latest_replay_to(path: &Path, replay: &Replay) -> io::Result<()> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+    let json = serde_json::to_string_pretty(replay).map_err(io::Error::other)?;
+    let tmp = path.with_extension("json.tmp");
+    fs::write(&tmp, json.as_bytes())?;
+    fs::rename(&tmp, path)?;
+    Ok(())
+}
+
+/// Load a [`Replay`] from `path`, returning `None` when the file is
+/// missing, corrupt, or carries a [`schema_version`](Replay::schema_version)
+/// other than [`REPLAY_SCHEMA_VERSION`].
+///
+/// Schema-mismatch is treated as "no replay" so the player just sees the
+/// "No replay recorded yet" caption rather than a half-loaded broken
+/// replay. Bumping [`REPLAY_SCHEMA_VERSION`] therefore invalidates every
+/// older save without further migration code.
+#[deprecated(
+    note = "single-slot replay storage replaced by the rolling history; \
+            use load_replay_history_from instead. Kept for the one-shot \
+            legacy migration."
+)]
+pub fn load_latest_replay_from(path: &Path) -> Option<Replay> {
+    let data = fs::read(path).ok()?;
+    let replay: Replay = serde_json::from_slice(&data).ok()?;
+    if replay.schema_version != REPLAY_SCHEMA_VERSION {
+        return None;
+    }
+    Some(replay)
+}
+
+/// Save a [`ReplayHistory`] atomically to `path` using the standard
+/// `.tmp` → rename contract.
+///
+/// The on-disk encoding is pretty-printed JSON; the file is intended to
+/// be small (≤ [`REPLAY_HISTORY_CAP`] entries, each carrying a few
+/// hundred move records at most) so the readability tradeoff is fine.
+pub fn save_replay_history_to(path: &Path, history: &ReplayHistory) -> io::Result<()> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+    let json = serde_json::to_string_pretty(history).map_err(io::Error::other)?;
+    let tmp = path.with_extension("json.tmp");
+    fs::write(&tmp, json.as_bytes())?;
+    fs::rename(&tmp, path)?;
+    Ok(())
+}
+
+/// Load a [`ReplayHistory`] from `path`, returning `None` when the file
+/// is missing, corrupt, or carries a [`schema_version`](ReplayHistory::schema_version)
+/// other than [`REPLAY_HISTORY_SCHEMA_VERSION`].
+///
+/// Individual [`Replay`] entries inside an otherwise-current history are
+/// filtered to only those carrying [`REPLAY_SCHEMA_VERSION`] — older
+/// entries are silently dropped so a future bump of the inner replay
+/// schema does not corrupt the wrapper.
+pub fn load_replay_history_from(path: &Path) -> Option<ReplayHistory> {
+    let data = fs::read(path).ok()?;
+    let history: ReplayHistory = serde_json::from_slice(&data).ok()?;
+    if history.schema_version != REPLAY_HISTORY_SCHEMA_VERSION {
+        return None;
+    }
+    let filtered: Vec<Replay> = history
+        .replays
+        .into_iter()
+        .filter(|r| r.schema_version == REPLAY_SCHEMA_VERSION)
+        .collect();
+    Some(ReplayHistory {
+        schema_version: REPLAY_HISTORY_SCHEMA_VERSION,
+        replays: filtered,
+    })
+}
+
+/// Append `replay` to the front of the rolling history at `path`,
+/// dropping the oldest entry once [`REPLAY_HISTORY_CAP`] is exceeded,
+/// and persist the updated history atomically.
+///
+/// If `path` has no existing history (missing file, corrupt, or
+/// schema-mismatched) a fresh [`ReplayHistory::default`] is used as the
+/// starting point so the new replay is always saved. The returned
+/// [`ReplayHistory`] is the exact value written to disk so callers can
+/// update an in-memory mirror (e.g. the Stats overlay's
+/// `ReplayHistoryResource`) without a follow-up `load`.
+pub fn append_replay_to_history(
+    path: &Path,
+    replay: Replay,
+) -> io::Result<ReplayHistory> {
+    let mut history = load_replay_history_from(path).unwrap_or_default();
+    // Most recent first. Reserve the front slot; pop the oldest if we
+    // exceed the cap so the file never grows unbounded.
+    history.replays.insert(0, replay);
+    if history.replays.len() > REPLAY_HISTORY_CAP {
+        history.replays.truncate(REPLAY_HISTORY_CAP);
+    }
+    save_replay_history_to(path, &history)?;
+    Ok(history)
+}
+
+/// One-shot migration from the legacy single-slot
+/// `latest_replay.json` file to the rolling [`ReplayHistory`] stored at
+/// `history_path`.
+///
+/// Behaviour matrix:
+/// - `history_path` already exists  → no-op (the rolling history wins).
+/// - `history_path` is absent and `latest_path` is absent → no-op.
+/// - `history_path` is absent and `latest_path` exists with a valid
+///   replay → seed a fresh history with that one replay and write it.
+/// - `history_path` is absent and `latest_path` exists but is corrupt /
+///   schema-mismatched → write an empty history (we know the player is
+///   on the new build and shouldn't keep being prompted to migrate).
+///
+/// The legacy `latest_replay.json` file is intentionally NOT deleted by
+/// this helper — keep it for one release as a safety net so a player
+/// rolling back to the previous build doesn't lose their last winning
+/// replay. The deletion is planned for the release after this one.
+pub fn migrate_legacy_latest_replay(latest_path: &Path, history_path: &Path) {
+    if history_path.exists() {
+        // Rolling history is authoritative once it exists.
+        return;
+    }
+    if !latest_path.exists() {
+        return;
+    }
+    // Use the deprecated loader directly — the migration is the one
+    // place we still consult the legacy file shape on purpose.
+    #[allow(deprecated)]
+    let legacy = load_latest_replay_from(latest_path);
+    let history = match legacy {
+        Some(replay) => ReplayHistory {
+            schema_version: REPLAY_HISTORY_SCHEMA_VERSION,
+            replays: vec![replay],
+        },
+        None => ReplayHistory::default(),
+    };
+    if let Err(e) = save_replay_history_to(history_path, &history) {
+        // Migration failure is non-fatal: on the next launch we'll just
+        // try again. We log to stderr rather than panic so headless
+        // tests stay quiet.
+        eprintln!(
+            "replay: failed to migrate legacy latest_replay.json into rolling history: {e}",
+        );
+    }
+}
+
+#[cfg(test)]
+// The legacy single-slot tests still exercise `save_latest_replay_to` /
+// `load_latest_replay_from` on purpose — they're the round-trip
+// guardrails for the migration source format.
+#[allow(deprecated)]
+mod tests {
+    use super::*;
+    use std::env;
+
+    fn tmp_path(name: &str) -> PathBuf {
+        env::temp_dir().join(format!("solitaire_test_replay_{name}.json"))
+    }
+
+    fn sample_replay() -> Replay {
+        let date = NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date");
+        Replay::new(
+            12345,
+            DrawMode::DrawThree,
+            GameMode::Classic,
+            134,
+            5_120,
+            date,
+            vec![
+                ReplayMove::StockClick,
+                ReplayMove::Move {
+                    from: PileType::Waste,
+                    to: PileType::Tableau(3),
+                    count: 1,
+                },
+                ReplayMove::StockClick,
+                ReplayMove::Move {
+                    from: PileType::Tableau(3),
+                    to: PileType::Foundation(0),
+                    count: 1,
+                },
+            ],
+        )
+    }
+
+    /// A non-trivial replay with mixed move kinds must round-trip
+    /// byte-identically through `save_latest_replay_to` /
+    /// `load_latest_replay_from`. Catches any future field that forgets
+    /// `Serialize`/`Deserialize` or breaks the on-disk format.
+    #[test]
+    fn replay_round_trips_through_save_and_load() {
+        let path = tmp_path("round_trip");
+        let _ = fs::remove_file(&path);
+
+        let replay = sample_replay();
+        save_latest_replay_to(&path, &replay).expect("save");
+
+        let loaded = load_latest_replay_from(&path).expect("load must succeed");
+        assert_eq!(loaded, replay, "round-trip must preserve every field");
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// A file written by an older schema (or a pre-`schema_version`
+    /// build) must be rejected. We write a minimal v0 fixture and assert
+    /// that `load_latest_replay_from` returns `None` so the player gets
+    /// a clean "no replay" state instead of a broken one.
+    #[test]
+    fn replay_legacy_schema_version_falls_through_to_none() {
+        let path = tmp_path("legacy_schema");
+        let _ = fs::remove_file(&path);
+
+        // No `schema_version` key — defaults to 0 via `schema_v0()`. Even
+        // if the rest of the JSON parses cleanly, the version gate must
+        // reject it.
+        let v0_json = r#"{
+            "seed": 1,
+            "draw_mode": "DrawOne",
+            "mode": "Classic",
+            "time_seconds": 60,
+            "final_score": 100,
+            "recorded_at": "2025-01-01",
+            "moves": []
+        }"#;
+        fs::write(&path, v0_json).expect("write v0 fixture");
+
+        assert!(
+            load_latest_replay_from(&path).is_none(),
+            "v0 replay must be rejected (schema gate)",
+        );
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Atomic-write contract — `.tmp` must not be left behind after
+    /// `save_latest_replay_to` returns. Mirrors the same check that
+    /// guards `save_game_state_to` in `storage.rs`.
+    #[test]
+    fn replay_save_is_atomic() {
+        let path = tmp_path("atomic");
+        let _ = fs::remove_file(&path);
+
+        save_latest_replay_to(&path, &sample_replay()).expect("save");
+        let tmp = path.with_extension("json.tmp");
+        assert!(!tmp.exists(), ".tmp must be cleaned up after rename");
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Loading from a path that does not exist must return `None`, not
+    /// panic or surface an `Err`.
+    #[test]
+    fn replay_missing_file_returns_none() {
+        let path = tmp_path("missing_xyz");
+        let _ = fs::remove_file(&path);
+        assert!(load_latest_replay_from(&path).is_none());
+    }
+
+    /// Loading from a corrupt / partially-written file must return
+    /// `None`, not surface a deserialiser error to the engine.
+    #[test]
+    fn replay_corrupt_file_returns_none() {
+        let path = tmp_path("corrupt");
+        fs::write(&path, b"not valid json!!!").expect("write");
+        assert!(load_latest_replay_from(&path).is_none());
+        let _ = fs::remove_file(&path);
+    }
+
+    // -----------------------------------------------------------------------
+    // ReplayHistory — rolling list of recent wins
+    // -----------------------------------------------------------------------
+
+    /// Build a [`Replay`] whose `final_score` carries `id` so tests can
+    /// assert ordering / identity without writing a deep equality match.
+    fn replay_with_id(id: i32) -> Replay {
+        let date = NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date");
+        Replay::new(
+            id as u64,
+            DrawMode::DrawOne,
+            GameMode::Classic,
+            60,
+            id,
+            date,
+            vec![ReplayMove::StockClick],
+        )
+    }
+
+    /// Pushing past [`REPLAY_HISTORY_CAP`] must drop the oldest entries —
+    /// the on-disk file (and the in-memory mirror returned by the helper)
+    /// stays bounded so the user's data dir never grows unbounded.
+    #[test]
+    fn append_replay_to_history_caps_at_eight() {
+        let path = tmp_path("history_cap");
+        let _ = fs::remove_file(&path);
+
+        let mut last_returned = ReplayHistory::default();
+        for i in 0..10 {
+            last_returned = append_replay_to_history(&path, replay_with_id(i))
+                .expect("append must succeed");
+        }
+
+        assert_eq!(
+            last_returned.replays.len(),
+            REPLAY_HISTORY_CAP,
+            "history must be capped at REPLAY_HISTORY_CAP entries",
+        );
+        // The most recent ten pushes were ids 0..=9; ids 9, 8, ..., 2
+        // survive (newest first), ids 0 and 1 aged out.
+        let ids: Vec<i32> = last_returned.replays.iter().map(|r| r.final_score).collect();
+        assert_eq!(
+            ids,
+            vec![9, 8, 7, 6, 5, 4, 3, 2],
+            "newest entries must survive, oldest must age out",
+        );
+
+        // The on-disk file must agree with the returned in-memory copy.
+        let loaded = load_replay_history_from(&path).expect("load must succeed");
+        assert_eq!(loaded, last_returned, "disk must mirror returned history");
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// `append_replay_to_history` must place new entries at index 0 so
+    /// the Stats overlay's default selector (most recent) lands on the
+    /// just-saved replay.
+    #[test]
+    fn append_replay_inserts_at_front() {
+        let path = tmp_path("history_front");
+        let _ = fs::remove_file(&path);
+
+        append_replay_to_history(&path, replay_with_id(1)).expect("append 1");
+        append_replay_to_history(&path, replay_with_id(2)).expect("append 2");
+        let history = append_replay_to_history(&path, replay_with_id(3)).expect("append 3");
+
+        let ids: Vec<i32> = history.replays.iter().map(|r| r.final_score).collect();
+        assert_eq!(
+            ids,
+            vec![3, 2, 1],
+            "history must be reverse-chronological (newest first)",
+        );
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// On first launch with the new code, a pre-existing
+    /// `latest_replay.json` must seed the new rolling history so the
+    /// player doesn't lose their last winning replay across the upgrade.
+    #[test]
+    fn legacy_latest_replay_migrates_to_history_on_first_launch() {
+        let latest = tmp_path("legacy_migrate_latest");
+        let history = tmp_path("legacy_migrate_history");
+        let _ = fs::remove_file(&latest);
+        let _ = fs::remove_file(&history);
+
+        // Seed the legacy file with a real replay.
+        let legacy_replay = sample_replay();
+        save_latest_replay_to(&latest, &legacy_replay).expect("seed legacy");
+        assert!(!history.exists(), "history file must not exist pre-migration");
+
+        migrate_legacy_latest_replay(&latest, &history);
+
+        assert!(history.exists(), "migration must create the history file");
+        let loaded = load_replay_history_from(&history)
+            .expect("post-migration history must load");
+        assert_eq!(loaded.replays.len(), 1, "history must hold exactly the legacy entry");
+        assert_eq!(loaded.replays[0], legacy_replay, "entry must equal the legacy replay");
+        // Legacy file is intentionally retained for one release as a
+        // safety net — see `migrate_legacy_latest_replay` doc comment.
+        assert!(latest.exists(), "legacy file must NOT be deleted by migration");
+
+        let _ = fs::remove_file(&latest);
+        let _ = fs::remove_file(&history);
+    }
+
+    /// When the rolling history file already exists, the migration must
+    /// be a no-op — we never want to overwrite the player's accumulated
+    /// history with a stale single-slot legacy entry.
+    #[test]
+    fn migrate_is_noop_when_history_already_exists() {
+        let latest = tmp_path("legacy_noop_latest");
+        let history = tmp_path("legacy_noop_history");
+        let _ = fs::remove_file(&latest);
+        let _ = fs::remove_file(&history);
+
+        save_latest_replay_to(&latest, &sample_replay()).expect("seed legacy");
+        let pre_existing = ReplayHistory {
+            schema_version: REPLAY_HISTORY_SCHEMA_VERSION,
+            replays: vec![replay_with_id(42)],
+        };
+        save_replay_history_to(&history, &pre_existing).expect("seed history");
+
+        migrate_legacy_latest_replay(&latest, &history);
+
+        let loaded = load_replay_history_from(&history).expect("load");
+        assert_eq!(loaded, pre_existing, "existing history must not be overwritten");
+
+        let _ = fs::remove_file(&latest);
+        let _ = fs::remove_file(&history);
+    }
+
+    /// A populated [`ReplayHistory`] must round-trip byte-identically
+    /// through `save_replay_history_to` / `load_replay_history_from`.
+    #[test]
+    fn replay_history_round_trips_through_save_and_load() {
+        let path = tmp_path("history_round_trip");
+        let _ = fs::remove_file(&path);
+
+        let history = ReplayHistory {
+            schema_version: REPLAY_HISTORY_SCHEMA_VERSION,
+            replays: vec![replay_with_id(7), replay_with_id(3), sample_replay()],
+        };
+        save_replay_history_to(&path, &history).expect("save");
+        let loaded = load_replay_history_from(&path).expect("load");
+        assert_eq!(loaded, history, "round-trip must preserve every field");
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// A file written by an older history schema must be rejected so the
+    /// player sees a clean empty history rather than a half-loaded one.
+    #[test]
+    fn replay_history_legacy_schema_version_falls_through_to_none() {
+        let path = tmp_path("history_legacy_schema");
+        let _ = fs::remove_file(&path);
+
+        // No `schema_version` key → defaults to 0 via `history_schema_v0()`.
+        let v0_json = r#"{
+            "replays": []
+        }"#;
+        fs::write(&path, v0_json).expect("write v0 fixture");
+
+        assert!(
+            load_replay_history_from(&path).is_none(),
+            "v0 history must be rejected (schema gate)",
+        );
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Atomic-write contract for the rolling history — `.tmp` must not be
+    /// left behind after `save_replay_history_to` returns.
+    #[test]
+    fn replay_history_save_is_atomic() {
+        let path = tmp_path("history_atomic");
+        let _ = fs::remove_file(&path);
+
+        save_replay_history_to(&path, &ReplayHistory::default()).expect("save");
+        let tmp = path.with_extension("json.tmp");
+        assert!(!tmp.exists(), ".tmp must be cleaned up after rename");
+
+        let _ = fs::remove_file(&path);
+    }
+}

solitaire_data/src/settings.rs

@@ -151,6 +151,36 @@ pub struct Settings {
     /// `#[serde(default = "default_tooltip_delay")]`.
     #[serde(default = "default_tooltip_delay")]
     pub tooltip_delay_secs: f32,
+    /// Multiplier applied to the post-game time-bonus score component
+    /// shown in the win-summary modal. Range
+    /// `[TIME_BONUS_MULTIPLIER_MIN, TIME_BONUS_MULTIPLIER_MAX]`
+    /// (`0.0`–`2.0`); default `1.0` keeps the existing behaviour.
+    ///
+    /// **COSMETIC ONLY** — this multiplier changes what the player
+    /// sees in the win modal's score breakdown but does **not** affect
+    /// achievement unlock thresholds, lifetime score totals, or
+    /// leaderboard submissions, which all use the raw, unmultiplied
+    /// score values produced by `solitaire_core`. Older
+    /// `settings.json` files written before this field existed
+    /// deserialize cleanly to `1.0` via
+    /// `#[serde(default = "default_time_bonus_multiplier")]`.
+    #[serde(default = "default_time_bonus_multiplier")]
+    pub time_bonus_multiplier: f32,
+    /// When `true`, the engine rejects new-game deals the
+    /// [`solitaire_core::solver`] cannot prove winnable, retrying
+    /// fresh seeds up to [`SOLVER_DEAL_RETRY_CAP`] attempts before
+    /// giving up and using the last tried seed. Off by default —
+    /// the solver adds a few hundred milliseconds of latency on the
+    /// pathological deals that hit the budget cap, and not every
+    /// player wants to wait. Older `settings.json` files written
+    /// before this field existed deserialize cleanly to `false` via
+    /// `#[serde(default)]`.
+    ///
+    /// Scope: only random-seed Classic-mode deals are filtered.
+    /// Daily challenges, replays, and explicit-seed requests skip the
+    /// solver retry loop — see `solitaire_engine::handle_new_game`.
+    #[serde(default)]
+    pub winnable_deals_only: bool,
 }
 
 fn default_draw_mode() -> DrawMode {
@@ -189,6 +219,36 @@ pub const TOOLTIP_DELAY_MAX_SECS: f32 = 1.5;
 /// Increment applied by the tooltip-delay decrement / increment buttons.
 pub const TOOLTIP_DELAY_STEP_SECS: f32 = 0.1;
 
+/// Lower bound of the player-tunable time-bonus multiplier. `0.0`
+/// disables the time-bonus row entirely (renders as "Off" in the UI).
+pub const TIME_BONUS_MULTIPLIER_MIN: f32 = 0.0;
+
+/// Upper bound of the player-tunable time-bonus multiplier. `2.0`
+/// doubles the displayed time bonus.
+pub const TIME_BONUS_MULTIPLIER_MAX: f32 = 2.0;
+
+/// Increment applied by the time-bonus multiplier decrement /
+/// increment buttons.
+pub const TIME_BONUS_MULTIPLIER_STEP: f32 = 0.1;
+
+/// Default value for [`Settings::time_bonus_multiplier`]. `1.0` keeps
+/// the displayed time bonus identical to the raw value produced by
+/// `solitaire_core::scoring::compute_time_bonus`.
+fn default_time_bonus_multiplier() -> f32 {
+    1.0
+}
+
+/// Maximum number of seed retries [`solitaire_engine::handle_new_game`]
+/// is willing to attempt before giving up and accepting the latest
+/// candidate seed when [`Settings::winnable_deals_only`] is on. If
+/// every retry comes back [`SolverResult::Unwinnable`] (which would
+/// be very unusual) we'd rather hand the player a possibly-unwinnable
+/// deal than spin forever on the main thread.
+///
+/// 50 attempts × ~50 ms median per solve = ~2.5 s worst-case stall —
+/// the upper bound on UI freeze when the toggle is on.
+pub const SOLVER_DEAL_RETRY_CAP: u32 = 50;
+
 impl Default for Settings {
     fn default() -> Self {
         Self {
@@ -206,14 +266,16 @@ impl Default for Settings {
             selected_theme_id: default_theme_id(),
             shown_achievement_onboarding: false,
             tooltip_delay_secs: default_tooltip_delay(),
+            time_bonus_multiplier: default_time_bonus_multiplier(),
+            winnable_deals_only: false,
         }
     }
 }
 
 impl Settings {
-    /// Clamps `sfx_volume`, `music_volume`, and `tooltip_delay_secs` into
+    /// Clamps `sfx_volume`, `music_volume`, `tooltip_delay_secs`, and
-    /// their respective ranges after deserialization or hand-editing of
+    /// `time_bonus_multiplier` into their respective ranges after
-    /// `settings.json`.
+    /// deserialization or hand-editing of `settings.json`.
     pub fn sanitized(self) -> Self {
         Self {
             sfx_volume: self.sfx_volume.clamp(0.0, 1.0),
@@ -221,6 +283,9 @@ impl Settings {
             tooltip_delay_secs: self
                 .tooltip_delay_secs
                 .clamp(TOOLTIP_DELAY_MIN_SECS, TOOLTIP_DELAY_MAX_SECS),
+            time_bonus_multiplier: self
+                .time_bonus_multiplier
+                .clamp(TIME_BONUS_MULTIPLIER_MIN, TIME_BONUS_MULTIPLIER_MAX),
             ..self
         }
     }
@@ -245,6 +310,20 @@ impl Settings {
             .clamp(TOOLTIP_DELAY_MIN_SECS, TOOLTIP_DELAY_MAX_SECS);
         self.tooltip_delay_secs
     }
+
+    /// Adjust the time-bonus multiplier by `delta`, clamped to
+    /// `[TIME_BONUS_MULTIPLIER_MIN, TIME_BONUS_MULTIPLIER_MAX]`. The
+    /// result is rounded to one decimal place so the readout stays
+    /// clean across repeated `±` clicks (avoids float drift like
+    /// `0.30000004`). Returns the new value.
+    pub fn adjust_time_bonus_multiplier(&mut self, delta: f32) -> f32 {
+        let raw = (self.time_bonus_multiplier + delta)
+            .clamp(TIME_BONUS_MULTIPLIER_MIN, TIME_BONUS_MULTIPLIER_MAX);
+        // Round to 1 decimal place — the slider step is 0.1, so this
+        // collapses any FP drift introduced by repeated additions.
+        self.time_bonus_multiplier = (raw * 10.0).round() / 10.0;
+        self.time_bonus_multiplier
+    }
 }
 
 /// Returns the platform-specific path to `settings.json`, or `None` if
@@ -375,6 +454,8 @@ mod tests {
             selected_theme_id: "default".to_string(),
             shown_achievement_onboarding: false,
             tooltip_delay_secs: default_tooltip_delay(),
+            time_bonus_multiplier: default_time_bonus_multiplier(),
+            winnable_deals_only: false,
         };
         save_settings_to(&path, &s).expect("save");
         let loaded = load_settings_from(&path);
@@ -689,4 +770,142 @@ mod tests {
         .sanitized();
         assert_eq!(s2.tooltip_delay_secs, TOOLTIP_DELAY_MAX_SECS);
     }
+
+    // -----------------------------------------------------------------------
+    // time_bonus_multiplier — cosmetic win-modal time-bonus weight
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn settings_time_bonus_multiplier_default_is_one() {
+        let s = Settings::default();
+        assert!(
+            (s.time_bonus_multiplier - 1.0).abs() < 1e-6,
+            "default time_bonus_multiplier must be 1.0 (no change to displayed bonus), got {}",
+            s.time_bonus_multiplier
+        );
+    }
+
+    #[test]
+    fn settings_time_bonus_multiplier_round_trip() {
+        let path = tmp_path("time_bonus_multiplier_round_trip");
+        let _ = fs::remove_file(&path);
+        let s = Settings {
+            time_bonus_multiplier: 1.5,
+            ..Settings::default()
+        };
+        save_settings_to(&path, &s).expect("save");
+        let loaded = load_settings_from(&path);
+        assert!(
+            (loaded.time_bonus_multiplier - 1.5).abs() < 1e-6,
+            "time_bonus_multiplier must survive serde round-trip; got {}",
+            loaded.time_bonus_multiplier
+        );
+        let _ = fs::remove_file(&path);
+    }
+
+    #[test]
+    fn legacy_settings_without_time_bonus_multiplier_deserializes_to_one() {
+        // A settings.json written before this field existed must
+        // deserialize cleanly to the existing 1.0 baseline so old
+        // players see no change to their win-modal bonuses.
+        let json = br#"{ "sfx_volume": 0.7, "first_run_complete": true }"#;
+        let s: Settings = serde_json::from_slice(json).unwrap_or_default();
+        assert!(
+            (s.time_bonus_multiplier - 1.0).abs() < 1e-6,
+            "legacy settings.json missing time_bonus_multiplier must deserialize to 1.0, got {}",
+            s.time_bonus_multiplier
+        );
+    }
+
+    #[test]
+    fn settings_time_bonus_multiplier_clamps_to_range() {
+        // Negative or oversized values from a hand-edited file must be
+        // clamped on load.
+        let s = Settings {
+            time_bonus_multiplier: -0.5,
+            ..Settings::default()
+        }
+        .sanitized();
+        assert_eq!(s.time_bonus_multiplier, TIME_BONUS_MULTIPLIER_MIN);
+
+        let s2 = Settings {
+            time_bonus_multiplier: 99.0,
+            ..Settings::default()
+        }
+        .sanitized();
+        assert_eq!(s2.time_bonus_multiplier, TIME_BONUS_MULTIPLIER_MAX);
+    }
+
+    #[test]
+    fn adjust_time_bonus_multiplier_clamps_and_rounds() {
+        let mut s = Settings { time_bonus_multiplier: 1.0, ..Default::default() };
+        // Step up to 1.1.
+        assert!((s.adjust_time_bonus_multiplier(0.1) - 1.1).abs() < 1e-6);
+        // Big positive jump clamps to TIME_BONUS_MULTIPLIER_MAX.
+        assert!(
+            (s.adjust_time_bonus_multiplier(99.0) - TIME_BONUS_MULTIPLIER_MAX).abs() < 1e-6
+        );
+        // Big negative jump clamps to TIME_BONUS_MULTIPLIER_MIN.
+        assert!(
+            (s.adjust_time_bonus_multiplier(-99.0) - TIME_BONUS_MULTIPLIER_MIN).abs() < 1e-6
+        );
+        assert_eq!(s.time_bonus_multiplier, 0.0);
+
+        // Repeated incremental adds must not drift past the 0.1 grid.
+        let mut s2 = Settings { time_bonus_multiplier: 0.0, ..Default::default() };
+        for _ in 0..10 {
+            s2.adjust_time_bonus_multiplier(0.1);
+        }
+        // After ten +0.1 steps, value should be exactly 1.0 (1 decimal).
+        assert!(
+            (s2.time_bonus_multiplier - 1.0).abs() < 1e-6,
+            "rounding should pin repeated 0.1 steps to the decimal grid, got {}",
+            s2.time_bonus_multiplier
+        );
+    }
+
+    // -----------------------------------------------------------------------
+    // winnable_deals_only — solver-backed deal filter toggle
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn settings_winnable_deals_only_default_is_false() {
+        // Off by default — the solver adds latency we shouldn't impose
+        // on every player without their consent.
+        assert!(
+            !Settings::default().winnable_deals_only,
+            "default winnable_deals_only must be false"
+        );
+    }
+
+    #[test]
+    fn settings_winnable_deals_only_round_trip() {
+        let path = tmp_path("winnable_deals_only_round_trip");
+        let _ = fs::remove_file(&path);
+        let s = Settings {
+            winnable_deals_only: true,
+            ..Settings::default()
+        };
+        save_settings_to(&path, &s).expect("save");
+        let loaded = load_settings_from(&path);
+        assert!(
+            loaded.winnable_deals_only,
+            "winnable_deals_only must survive serde round-trip"
+        );
+        let _ = fs::remove_file(&path);
+    }
+
+    #[test]
+    fn legacy_settings_without_winnable_deals_only_deserializes_to_false() {
+        // A settings.json written before this field existed must
+        // deserialize cleanly to `false` (the default-off behaviour)
+        // rather than failing the whole load or surprising the player
+        // by switching the toggle on.
+        let json = br#"{ "sfx_volume": 0.7, "first_run_complete": true }"#;
+        let s: Settings = serde_json::from_slice(json).unwrap_or_default();
+        assert!(
+            !s.winnable_deals_only,
+            "legacy settings.json missing winnable_deals_only must deserialize to false"
+        );
+    }
 }

solitaire_data/src/stats.rs

@@ -5,16 +5,35 @@
 //! `update_on_win` method that depends on [`DrawMode`] from `solitaire_core`.
 
 use chrono::Utc;
-use solitaire_core::game_state::DrawMode;
+use solitaire_core::game_state::{DrawMode, GameMode};
 
 pub use solitaire_sync::StatsSnapshot;
 
 /// Extension trait providing game-logic mutation helpers for [`StatsSnapshot`].
 ///
-/// Import this trait alongside `StatsSnapshot` to use `update_on_win`.
+/// Import this trait alongside `StatsSnapshot` to use `update_on_win`
+/// and [`StatsExt::update_per_mode_bests`].
 pub trait StatsExt {
     /// Updates rolling statistics from a completed game win. Call once per `GameWonEvent`.
+    ///
+    /// Tracks lifetime totals only — per-mode best scores and times are
+    /// updated separately via [`StatsExt::update_per_mode_bests`] so the
+    /// long-standing call sites that only know about [`DrawMode`] keep
+    /// compiling.
     fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawMode);
+
+    /// Updates the per-mode best score and fastest-win-time fields for the
+    /// given [`GameMode`]. Call alongside [`StatsExt::update_on_win`] from
+    /// the win handler.
+    ///
+    /// Behaviour:
+    /// - `Classic`, `Zen`, `Challenge`: updates the matching `*_best_score`
+    ///   (max) and `*_fastest_win_seconds` (zero-aware min — 0 means
+    ///   "no win recorded yet").
+    /// - `TimeAttack`: no-op. Time Attack uses session-level scoring (count
+    ///   of wins in 10 minutes); a per-game best wouldn't compose with
+    ///   the other modes' single-game scoring.
+    fn update_per_mode_bests(&mut self, score: i32, time_seconds: u64, mode: GameMode);
 }
 
 impl StatsExt for StatsSnapshot {
@@ -51,6 +70,43 @@ impl StatsExt for StatsSnapshot {
 
         self.last_modified = Utc::now();
     }
+
+    fn update_per_mode_bests(&mut self, score: i32, time_seconds: u64, mode: GameMode) {
+        let score_u32 = score.max(0) as u32;
+        // Zero-aware min — 0 means "no win recorded yet" for the per-mode
+        // fastest fields, so we must not let a real time get clobbered to 0.
+        // (Mirrors the merge logic in `solitaire_sync::merge`.)
+        let min_ignore_zero = |existing: u64, candidate: u64| -> u64 {
+            if existing == 0 {
+                candidate
+            } else if candidate == 0 {
+                existing
+            } else {
+                existing.min(candidate)
+            }
+        };
+        match mode {
+            GameMode::Classic => {
+                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);
+            }
+            GameMode::Zen => {
+                self.zen_best_score = self.zen_best_score.max(score_u32);
+                self.zen_fastest_win_seconds =
+                    min_ignore_zero(self.zen_fastest_win_seconds, time_seconds);
+            }
+            GameMode::Challenge => {
+                self.challenge_best_score = self.challenge_best_score.max(score_u32);
+                self.challenge_fastest_win_seconds =
+                    min_ignore_zero(self.challenge_fastest_win_seconds, time_seconds);
+            }
+            // Time Attack uses its own session-level scoring; a per-game best
+            // wouldn't compose with the other modes' single-game numbers.
+            GameMode::TimeAttack => {}
+        }
+        self.last_modified = Utc::now();
+    }
 }
 
 #[cfg(test)]
@@ -177,4 +233,123 @@ mod tests {
         s.update_on_win(200, 60, &DrawMode::DrawOne);
         assert_eq!(s.lifetime_score, u64::MAX, "lifetime_score must saturate, not overflow");
     }
+
+    // -----------------------------------------------------------------------
+    // Per-mode bests
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn classic_win_updates_classic_best_score_only() {
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(1500, 200, GameMode::Classic);
+        assert_eq!(s.classic_best_score, 1500);
+        assert_eq!(s.classic_fastest_win_seconds, 200);
+        // Other modes untouched.
+        assert_eq!(s.zen_best_score, 0);
+        assert_eq!(s.zen_fastest_win_seconds, 0);
+        assert_eq!(s.challenge_best_score, 0);
+        assert_eq!(s.challenge_fastest_win_seconds, 0);
+    }
+
+    #[test]
+    fn zen_win_updates_zen_best_score_only() {
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(1800, 600, GameMode::Zen);
+        assert_eq!(s.zen_best_score, 1800);
+        assert_eq!(s.zen_fastest_win_seconds, 600);
+        assert_eq!(s.classic_best_score, 0);
+        assert_eq!(s.challenge_best_score, 0);
+    }
+
+    #[test]
+    fn challenge_win_updates_challenge_best_score_only() {
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(2400, 480, GameMode::Challenge);
+        assert_eq!(s.challenge_best_score, 2400);
+        assert_eq!(s.challenge_fastest_win_seconds, 480);
+        assert_eq!(s.classic_best_score, 0);
+        assert_eq!(s.zen_best_score, 0);
+    }
+
+    #[test]
+    fn time_attack_win_does_not_touch_per_mode_bests() {
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(9999, 1, GameMode::TimeAttack);
+        assert_eq!(s.classic_best_score, 0);
+        assert_eq!(s.zen_best_score, 0);
+        assert_eq!(s.challenge_best_score, 0);
+        assert_eq!(s.classic_fastest_win_seconds, 0);
+        assert_eq!(s.zen_fastest_win_seconds, 0);
+        assert_eq!(s.challenge_fastest_win_seconds, 0);
+    }
+
+    #[test]
+    fn per_mode_best_score_takes_max_across_calls() {
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(500, 200, GameMode::Classic);
+        s.update_per_mode_bests(200, 200, GameMode::Classic);
+        s.update_per_mode_bests(900, 200, GameMode::Classic);
+        assert_eq!(s.classic_best_score, 900);
+    }
+
+    #[test]
+    fn per_mode_fastest_uses_zero_aware_min() {
+        // First Classic win: 240s. Field starts at 0 (no win yet) — we
+        // must adopt 240, not stay at 0 like a naive `min` would.
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(100, 240, GameMode::Classic);
+        assert_eq!(s.classic_fastest_win_seconds, 240);
+        // Faster Classic win replaces it.
+        s.update_per_mode_bests(100, 120, GameMode::Classic);
+        assert_eq!(s.classic_fastest_win_seconds, 120);
+        // Slower Classic win does not.
+        s.update_per_mode_bests(100, 300, GameMode::Classic);
+        assert_eq!(s.classic_fastest_win_seconds, 120);
+    }
+
+    #[test]
+    fn negative_score_treated_as_zero_in_per_mode() {
+        let mut s = StatsSnapshot::default();
+        s.update_per_mode_bests(-50, 240, GameMode::Classic);
+        assert_eq!(s.classic_best_score, 0);
+        // Time still recorded — a win with a low score is still a win.
+        assert_eq!(s.classic_fastest_win_seconds, 240);
+    }
+
+    #[test]
+    fn legacy_stats_without_per_mode_fields_deserializes_to_zero() {
+        // A pre-per-mode `stats.json` must still deserialise cleanly:
+        // every new field falls back to 0 via `#[serde(default)]` so
+        // updating the binary never wipes the player's old stats file.
+        let legacy_json = r#"{
+            "games_played": 12,
+            "games_won": 5,
+            "games_lost": 7,
+            "win_streak_current": 1,
+            "win_streak_best": 3,
+            "avg_time_seconds": 240,
+            "fastest_win_seconds": 180,
+            "lifetime_score": 8500,
+            "best_single_score": 2200,
+            "draw_one_wins": 4,
+            "draw_three_wins": 1,
+            "last_modified": "2026-04-29T12:00:00Z"
+        }"#;
+
+        let s: StatsSnapshot = serde_json::from_str(legacy_json)
+            .expect("legacy payload must deserialise without per-mode fields");
+
+        // Pre-existing fields kept their values.
+        assert_eq!(s.games_played, 12);
+        assert_eq!(s.best_single_score, 2200);
+        assert_eq!(s.fastest_win_seconds, 180);
+
+        // Every new per-mode field defaulted to 0 ("no win yet").
+        assert_eq!(s.classic_best_score, 0);
+        assert_eq!(s.classic_fastest_win_seconds, 0);
+        assert_eq!(s.zen_best_score, 0);
+        assert_eq!(s.zen_fastest_win_seconds, 0);
+        assert_eq!(s.challenge_best_score, 0);
+        assert_eq!(s.challenge_fastest_win_seconds, 0);
+    }
 }

solitaire_data/src/storage.rs

@@ -6,7 +6,9 @@
 use std::fs;
 use std::io;
 use std::path::{Path, PathBuf};
+use std::time::{SystemTime, UNIX_EPOCH};
 
+use serde::{Deserialize, Serialize};
 use solitaire_core::game_state::{GameState, GAME_STATE_SCHEMA_VERSION};
 
 use crate::stats::StatsSnapshot;
@@ -14,6 +16,7 @@ use crate::stats::StatsSnapshot;
 const APP_DIR_NAME: &str = "solitaire_quest";
 const STATS_FILE_NAME: &str = "stats.json";
 const GAME_STATE_FILE_NAME: &str = "game_state.json";
+const TIME_ATTACK_SESSION_FILE_NAME: &str = "time_attack_session.json";
 
 /// Returns the platform-specific path to `stats.json`, or `None` if
 /// `dirs::data_dir()` is unavailable (e.g. minimal Linux containers).
@@ -139,6 +142,131 @@ pub fn cleanup_orphaned_tmp_files() -> io::Result<()> {
     Ok(())
 }
 
+// ---------------------------------------------------------------------------
+// Time Attack session (mode-specific sibling of game_state.json)
+// ---------------------------------------------------------------------------
+//
+// `GameState` carries `mode: GameMode`, so an in-progress Zen / Challenge /
+// Classic / TimeAttack deal is already round-tripped through `game_state.json`
+// — closing the window mid-deal in any of those modes restores the deal on
+// next launch. Time Attack adds a 10-minute session window and a per-session
+// win counter that live OUTSIDE `GameState` (in `TimeAttackResource` on the
+// engine side), so they are NOT covered by the game-state save/load. This
+// sibling file persists just that extra session-level state.
+//
+// The Bevy plugin layer (`solitaire_engine::time_attack_plugin`) is the only
+// caller. The file lives next to `game_state.json` in the same data dir and
+// is written using the same `.tmp` → rename atomic-write contract that the
+// rest of `storage.rs` uses.
+
+/// Persisted state for an in-progress Time Attack session.
+///
+/// Fields mirror the live `TimeAttackResource` minus the `active` flag (the
+/// presence of the file *is* the active flag — a missing file means no
+/// session in progress).
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct TimeAttackSession {
+    /// Seconds remaining in the 10-minute window when the save was written.
+    pub remaining_secs: f32,
+    /// Wins accumulated during the session so far.
+    pub wins: u32,
+    /// Wall-clock instant the save was written, as unix seconds. Used at
+    /// load time to detect whether the session window expired in real
+    /// time while the app was closed and to decrement `remaining_secs`
+    /// by the real elapsed time so the resumed session reflects how
+    /// long the window has actually been running.
+    pub saved_at_unix_secs: u64,
+}
+
+/// Returns the platform-specific path to `time_attack_session.json`, or
+/// `None` if `dirs::data_dir()` is unavailable.
+pub fn time_attack_session_path() -> Option<PathBuf> {
+    dirs::data_dir().map(|d| d.join(APP_DIR_NAME).join(TIME_ATTACK_SESSION_FILE_NAME))
+}
+
+/// Save a Time Attack session atomically. Mirrors `save_game_state_to`'s
+/// `.tmp` → rename contract.
+pub fn save_time_attack_session_to(path: &Path, session: &TimeAttackSession) -> io::Result<()> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)?;
+    }
+    let json = serde_json::to_string_pretty(session).map_err(io::Error::other)?;
+    let tmp = path.with_extension("json.tmp");
+    fs::write(&tmp, json.as_bytes())?;
+    fs::rename(&tmp, path)?;
+    Ok(())
+}
+
+/// Load a Time Attack session from `path`, decrementing `remaining_secs`
+/// by the wall-clock time elapsed between the save and now.
+///
+/// Returns `None` when:
+/// - the file is missing or unreadable,
+/// - the JSON is corrupt / malformed, or
+/// - the session window expired during the time the app was closed
+///   (`saved_at_unix_secs + remaining_secs <= now_unix_secs`).
+///
+/// The `now_unix_secs` parameter is injectable so unit tests can simulate
+/// arbitrary wall-clock gaps without touching the real system clock. The
+/// public companion [`load_time_attack_session_from`] resolves "now" from
+/// `SystemTime::now()`.
+pub fn load_time_attack_session_from_at(
+    path: &Path,
+    now_unix_secs: u64,
+) -> Option<TimeAttackSession> {
+    let data = fs::read(path).ok()?;
+    let session: TimeAttackSession = serde_json::from_slice(&data).ok()?;
+    // Compute wall-clock elapsed seconds since the save was written.
+    // Saturating subtraction guards against a clock that moved backwards
+    // (rare, but possible across NTP corrections or VM clock drift).
+    let elapsed = now_unix_secs.saturating_sub(session.saved_at_unix_secs);
+    let remaining = session.remaining_secs - elapsed as f32;
+    if remaining <= 0.0 {
+        return None;
+    }
+    Some(TimeAttackSession {
+        remaining_secs: remaining,
+        wins: session.wins,
+        saved_at_unix_secs: session.saved_at_unix_secs,
+    })
+}
+
+/// Load a Time Attack session from `path`, using `SystemTime::now()` as
+/// the reference for the wall-clock-elapsed adjustment.
+///
+/// See [`load_time_attack_session_from_at`] for the rules under which
+/// the call returns `None` (missing file, corrupt JSON, expired window).
+pub fn load_time_attack_session_from(path: &Path) -> Option<TimeAttackSession> {
+    let now = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_or(0, |d| d.as_secs());
+    load_time_attack_session_from_at(path, now)
+}
+
+/// Delete the Time Attack session file (called on session end, on session
+/// start, or on game completion). Silently ignores `NotFound` errors.
+pub fn delete_time_attack_session_at(path: &Path) -> io::Result<()> {
+    match fs::remove_file(path) {
+        Ok(()) => Ok(()),
+        Err(e) if e.kind() == io::ErrorKind::NotFound => Ok(()),
+        Err(e) => Err(e),
+    }
+}
+
+/// Convenience helper for callers that want to stamp a session with the
+/// current wall-clock time. Equivalent to constructing the struct
+/// manually and setting `saved_at_unix_secs` to `SystemTime::now()`.
+pub fn time_attack_session_with_now(remaining_secs: f32, wins: u32) -> TimeAttackSession {
+    let now = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_or(0, |d| d.as_secs());
+    TimeAttackSession {
+        remaining_secs,
+        wins,
+        saved_at_unix_secs: now,
+    }
+}
+
 /// Inner helper: delete `*.json.tmp` entries inside `dir`.
 ///
 /// Per-file errors (already deleted, permission denied) are silently ignored.
@@ -387,4 +515,190 @@ mod tests {
         let loaded = load_stats_from(&stats_path);
         assert_eq!(loaded, StatsSnapshot::default());
     }
+
+    // -----------------------------------------------------------------------
+    // Time Attack session persistence
+    //
+    // Documents the contract that closing the window mid-Time-Attack does
+    // NOT lose the 10-minute window or the running win count. Classic /
+    // Zen / Challenge are covered by `game_state.json` because their entire
+    // mid-deal state lives in `GameState.mode` + `GameState.piles`; Time
+    // Attack additionally needs the session timer + wins counter, both of
+    // which live in `TimeAttackResource` on the engine side and are NOT
+    // part of `GameState`. This sibling file persists exactly that.
+    // -----------------------------------------------------------------------
+
+    fn ta_path(name: &str) -> PathBuf {
+        env::temp_dir().join(format!("solitaire_test_ta_{name}.json"))
+    }
+
+    /// Round-trip a session that was saved "just now" (zero wall-clock
+    /// elapsed). All three persisted fields must come back unchanged.
+    #[test]
+    fn time_attack_session_round_trips_through_save_and_load() {
+        let path = ta_path("round_trip");
+        let _ = fs::remove_file(&path);
+
+        // Use a fixed unix timestamp so the load step (which receives the
+        // SAME timestamp as "now") sees zero wall-clock elapsed.
+        let saved_at: u64 = 1_800_000_000;
+        let session = TimeAttackSession {
+            remaining_secs: 240.0,
+            wins: 3,
+            saved_at_unix_secs: saved_at,
+        };
+        save_time_attack_session_to(&path, &session).expect("save");
+
+        let loaded = load_time_attack_session_from_at(&path, saved_at)
+            .expect("session must load when not yet expired");
+        assert!(
+            (loaded.remaining_secs - 240.0).abs() < 0.01,
+            "remaining_secs must be unchanged when no wall-clock time has passed; got {}",
+            loaded.remaining_secs,
+        );
+        assert_eq!(loaded.wins, 3, "wins must round-trip");
+        assert_eq!(loaded.saved_at_unix_secs, saved_at, "timestamp must round-trip");
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// A session whose window expired entirely between launches must be
+    /// discarded on load — the caller starts fresh rather than resuming a
+    /// dead session.
+    #[test]
+    fn time_attack_session_discarded_when_expired_between_launches() {
+        let path = ta_path("expired");
+        let _ = fs::remove_file(&path);
+
+        // Saved 20 minutes ago with 240 s remaining — long expired.
+        let saved_at: u64 = 1_800_000_000;
+        let session = TimeAttackSession {
+            remaining_secs: 240.0,
+            wins: 5,
+            saved_at_unix_secs: saved_at,
+        };
+        save_time_attack_session_to(&path, &session).expect("save");
+
+        // 20 minutes (1200 s) later → 240 - 1200 = -960 s remaining.
+        let now = saved_at + 1200;
+        assert!(
+            load_time_attack_session_from_at(&path, now).is_none(),
+            "an expired session must return None so the player starts fresh",
+        );
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// The `remaining_secs` returned at load time must be the persisted
+    /// value minus the wall-clock seconds that elapsed while the app was
+    /// closed.
+    #[test]
+    fn time_attack_session_remaining_secs_decremented_by_real_elapsed() {
+        let path = ta_path("decremented");
+        let _ = fs::remove_file(&path);
+
+        let saved_at: u64 = 1_800_000_000;
+        let session = TimeAttackSession {
+            remaining_secs: 240.0,
+            wins: 2,
+            saved_at_unix_secs: saved_at,
+        };
+        save_time_attack_session_to(&path, &session).expect("save");
+
+        // 60 s elapsed in real time → expect 180 s remaining.
+        let now = saved_at + 60;
+        let loaded = load_time_attack_session_from_at(&path, now)
+            .expect("session must still load — 180 s left");
+        assert!(
+            (loaded.remaining_secs - 180.0).abs() < 5.0,
+            "remaining_secs ≈ 180 ± 5 s after a 60 s wall-clock gap; got {}",
+            loaded.remaining_secs,
+        );
+        assert_eq!(loaded.wins, 2, "wins must survive the elapsed adjustment");
+
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Atomic-write contract — `.tmp` must not be left behind after
+    /// `save_time_attack_session_to` returns.
+    #[test]
+    fn time_attack_session_save_is_atomic() {
+        let path = ta_path("atomic");
+        let session = TimeAttackSession {
+            remaining_secs: 100.0,
+            wins: 0,
+            saved_at_unix_secs: 1_800_000_000,
+        };
+        save_time_attack_session_to(&path, &session).expect("save");
+        let tmp = path.with_extension("json.tmp");
+        assert!(!tmp.exists(), ".tmp must be cleaned up after rename");
+        let _ = fs::remove_file(&path);
+    }
+
+    /// Loading from a path that does not exist must return `None`, not
+    /// panic.
+    #[test]
+    fn time_attack_session_missing_file_returns_none() {
+        let path = ta_path("missing_xyz");
+        let _ = fs::remove_file(&path);
+        assert!(load_time_attack_session_from_at(&path, 0).is_none());
+    }
+
+    /// Loading from a corrupt / partially-written file must return `None`,
+    /// not surface a deserialiser error.
+    #[test]
+    fn time_attack_session_corrupt_file_returns_none() {
+        let path = ta_path("corrupt");
+        fs::write(&path, b"not valid json!!!").expect("write");
+        assert!(load_time_attack_session_from_at(&path, 0).is_none());
+        let _ = fs::remove_file(&path);
+    }
+
+    /// `delete_time_attack_session_at` removes the file when it exists
+    /// and returns `Ok(())` when it does not.
+    #[test]
+    fn time_attack_session_delete_handles_present_and_absent() {
+        let path = ta_path("delete");
+        let session = TimeAttackSession {
+            remaining_secs: 50.0,
+            wins: 0,
+            saved_at_unix_secs: 1_800_000_000,
+        };
+        save_time_attack_session_to(&path, &session).expect("save");
+        assert!(path.exists());
+        delete_time_attack_session_at(&path).expect("delete");
+        assert!(!path.exists());
+        // Second delete on the now-absent file must succeed.
+        delete_time_attack_session_at(&path).expect("missing-file delete is ok");
+    }
+
+    /// A session whose `saved_at_unix_secs` is in the future (e.g. the
+    /// system clock moved backward across NTP correction) must NOT be
+    /// rejected as expired. Saturating subtraction must clamp the
+    /// "elapsed" value to zero.
+    #[test]
+    fn time_attack_session_handles_clock_running_backwards() {
+        let path = ta_path("clock_backwards");
+        let _ = fs::remove_file(&path);
+
+        let saved_at: u64 = 1_800_000_000;
+        let session = TimeAttackSession {
+            remaining_secs: 60.0,
+            wins: 1,
+            saved_at_unix_secs: saved_at,
+        };
+        save_time_attack_session_to(&path, &session).expect("save");
+
+        // "now" is BEFORE the saved time — should not crash, should not expire.
+        let now_in_past = saved_at - 100;
+        let loaded = load_time_attack_session_from_at(&path, now_in_past)
+            .expect("clock-backwards must not discard the session");
+        assert!(
+            (loaded.remaining_secs - 60.0).abs() < 0.01,
+            "remaining_secs must clamp elapsed to 0 when clock ran backwards; got {}",
+            loaded.remaining_secs,
+        );
+
+        let _ = fs::remove_file(&path);
+    }
 }

solitaire_data/src/sync_client.rs

@@ -16,6 +16,7 @@ use solitaire_sync::{ChallengeGoal, LeaderboardEntry, SyncPayload, SyncResponse}
 
 use crate::{
     auth_tokens::{load_access_token, load_refresh_token, store_tokens},
+    replay::Replay,
     settings::SyncBackend,
     SyncError, SyncProvider,
 };
@@ -356,6 +357,54 @@ impl SyncProvider for SolitaireServerClient {
 
         extract_leaderboard_body(resp).await
     }
+
+    /// Upload a winning replay to `POST /api/replays`. Mirrors the
+    /// `push` auth flow: 401 triggers a token refresh and one retry.
+    /// Non-success statuses are surfaced as the relevant `SyncError`
+    /// variant so the engine's push-on-win system can downgrade
+    /// network/auth failures into a quiet log without aborting the
+    /// game flow.
+    async fn push_replay(&self, replay: &Replay) -> Result<(), SyncError> {
+        let token = self.access_token()?;
+        let url = format!("{}/api/replays", self.base_url);
+
+        let resp = self
+            .client
+            .post(&url)
+            .bearer_auth(&token)
+            .json(replay)
+            .send()
+            .await
+            .map_err(|e| SyncError::Network(e.to_string()))?;
+
+        if resp.status() == reqwest::StatusCode::UNAUTHORIZED {
+            self.refresh_token().await?;
+            let new_token = self.access_token()?;
+            let resp = self
+                .client
+                .post(&url)
+                .bearer_auth(new_token)
+                .json(replay)
+                .send()
+                .await
+                .map_err(|e| SyncError::Network(e.to_string()))?;
+            return check_replay_status(resp.status());
+        }
+
+        check_replay_status(resp.status())
+    }
+}
+
+fn check_replay_status(status: reqwest::StatusCode) -> Result<(), SyncError> {
+    if status.is_success() {
+        Ok(())
+    } else if status == reqwest::StatusCode::UNAUTHORIZED
+        || status == reqwest::StatusCode::FORBIDDEN
+    {
+        Err(SyncError::Auth(format!("server returned {status}")))
+    } else {
+        Err(SyncError::Network(format!("server returned {status}")))
+    }
 }
 
 // ---------------------------------------------------------------------------

solitaire_engine/src/achievement_plugin.rs

@@ -25,6 +25,7 @@ use crate::events::{
 use crate::font_plugin::FontResource;
 use crate::game_plugin::GameMutation;
 use crate::progress_plugin::{LevelUpEvent, ProgressResource, ProgressStoragePath, ProgressUpdate};
+use crate::replay_playback::ReplayPlaybackState;
 use crate::resources::GameStateResource;
 use crate::settings_plugin::{SettingsResource, SettingsStoragePath};
 use crate::stats_plugin::{StatsResource, StatsUpdate};
@@ -116,7 +117,12 @@ impl Plugin for AchievementPlugin {
                     .after(StatsUpdate),
             )
             .add_systems(Update, toggle_achievements_screen)
-            .add_systems(Update, handle_achievements_close_button);
+            .add_systems(Update, handle_achievements_close_button)
+            // Event-driven unlock: observe `ReplayPlaybackState` and unlock
+            // `cinephile` the first time playback runs to natural completion.
+            // Reads the resource via `Option<Res<_>>` so headless tests that
+            // omit `ReplayPlaybackPlugin` still build.
+            .add_systems(Update, evaluate_cinephile_on_replay_completion);
     }
 }
 
@@ -222,6 +228,66 @@ fn evaluate_on_win(
             }
 }
 
+/// Cinephile unlock observer.
+///
+/// Watches [`ReplayPlaybackState`] and unlocks the `cinephile` achievement
+/// the first time the resource transitions from `Playing` to `Completed` —
+/// i.e. the player watched a saved replay all the way through. The Stop
+/// button transitions `Playing` → `Inactive` directly (never via
+/// `Completed`), so manual aborts do not trigger the unlock.
+///
+/// Idempotent: once the record is unlocked, subsequent Playing → Completed
+/// transitions are a no-op (no extra `AchievementUnlockedEvent`, no extra
+/// disk write). The transition itself is debounced by tracking the
+/// previous frame's `is_playing()` state in a `Local<bool>` — without
+/// this, a freshly-spawned `Completed` state would re-fire each frame
+/// during the linger window.
+///
+/// Reads `ReplayPlaybackState` via `Option<Res<_>>` so achievement tests
+/// that omit `ReplayPlaybackPlugin` still build cleanly.
+fn evaluate_cinephile_on_replay_completion(
+    state: Option<Res<ReplayPlaybackState>>,
+    // `Local` collides with `chrono::Local` imported at the top of this
+    // module — fully qualify so the Bevy system parameter resolves
+    // correctly.
+    mut last_was_playing: bevy::prelude::Local<bool>,
+    mut achievements: ResMut<AchievementsResource>,
+    mut unlocks: MessageWriter<AchievementUnlockedEvent>,
+    path: Res<AchievementsStoragePath>,
+) {
+    let Some(state) = state else {
+        return;
+    };
+
+    // Detect the Playing → Completed transition: was playing last frame,
+    // is now completed. Direct Playing → Inactive (Stop button) does not
+    // satisfy this guard because it never enters `Completed`.
+    let now_playing = state.is_playing();
+    let now_completed = state.is_completed();
+    let just_completed = *last_was_playing && now_completed;
+    *last_was_playing = now_playing;
+
+    if !just_completed {
+        return;
+    }
+
+    let Some(record) = achievements.0.iter_mut().find(|r| r.id == "cinephile") else {
+        return;
+    };
+    if record.unlocked {
+        return;
+    }
+    record.unlock(Utc::now());
+    record.reward_granted = true;
+    unlocks.write(AchievementUnlockedEvent(record.clone()));
+
+    if let Some(target) = &path.0
+        && let Err(e) = save_achievements_to(target, &achievements.0)
+    {
+        warn!("failed to save achievements after cinephile unlock: {e}");
+    }
+}
+
 /// Achievement-onboarding cue.
 ///
 /// On the player's very first win — and only their first — fires a single
@@ -1149,9 +1215,215 @@ mod tests {
         );
     }
 
-    /// Without any `GameWonEvent` arriving the system must be a no-op:
+    // -----------------------------------------------------------------------
-    /// no toast, no flag flip — even on update ticks where stats happen
+    // Cinephile (event-driven via ReplayPlaybackState)
-    /// to read `games_won == 1`.
+    // -----------------------------------------------------------------------
+
+    use crate::replay_playback::ReplayPlaybackState;
+    use solitaire_data::{Replay, ReplayMove};
+    use chrono::NaiveDate;
+    use solitaire_core::game_state::{DrawMode, GameMode};
+
+    /// Headless app variant that injects a default `ReplayPlaybackState`
+    /// directly (no `ReplayPlaybackPlugin`) so we can drive the resource
+    /// by hand. The achievement plugin's cinephile observer reads it via
+    /// `Option<Res<_>>` so the absence of the playback plugin is safe.
+    fn cinephile_app() -> App {
+        let mut app = headless_app();
+        app.init_resource::<ReplayPlaybackState>();
+        app
+    }
+
+    fn dummy_replay() -> Replay {
+        Replay::new(
+            1,
+            DrawMode::DrawOne,
+            GameMode::Classic,
+            10,
+            100,
+            NaiveDate::from_ymd_opt(2026, 5, 5).expect("valid date"),
+            vec![ReplayMove::StockClick],
+        )
+    }
+
+    fn cinephile_unlocked(app: &App) -> bool {
+        app.world()
+            .resource::<AchievementsResource>()
+            .0
+            .iter()
+            .find(|r| r.id == "cinephile")
+            .map(|r| r.unlocked)
+            .unwrap_or(false)
+    }
+
+    fn cinephile_unlocks_emitted(app: &App) -> usize {
+        let events = app.world().resource::<Messages<AchievementUnlockedEvent>>();
+        let mut cursor = events.get_cursor();
+        cursor
+            .read(events)
+            .filter(|e| e.0.id == "cinephile")
+            .count()
+    }
+
+    /// The cinephile record must be seeded on plugin init like every other
+    /// achievement, so the observer can find and mutate it later.
+    #[test]
+    fn cinephile_record_seeded_by_plugin() {
+        let app = cinephile_app();
+        let records = &app.world().resource::<AchievementsResource>().0;
+        assert!(
+            records.iter().any(|r| r.id == "cinephile" && !r.unlocked),
+            "cinephile record must be seeded as locked",
+        );
+    }
+
+    /// Drive Inactive → Playing → Completed and assert the cinephile
+    /// achievement unlocks and exactly one `AchievementUnlockedEvent` is
+    /// emitted.
+    #[test]
+    fn cinephile_unlocks_on_replay_completion() {
+        let mut app = cinephile_app();
+
+        // Frame 1: enter Playing. The observer's first sample sees
+        // `last_was_playing = false` and `now_playing = true`.
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Playing {
+                replay: dummy_replay(),
+                cursor: 0,
+                secs_to_next: 0.0,
+            };
+        app.update();
+        assert!(
+            !cinephile_unlocked(&app),
+            "Playing alone must not unlock cinephile",
+        );
+
+        // Frame 2: transition to Completed. The observer must detect
+        // `last_was_playing = true && now_completed = true` and unlock.
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Completed;
+        app.update();
+
+        assert!(
+            cinephile_unlocked(&app),
+            "cinephile must unlock on Playing → Completed transition",
+        );
+        assert_eq!(
+            cinephile_unlocks_emitted(&app),
+            1,
+            "exactly one AchievementUnlockedEvent must fire for cinephile",
+        );
+    }
+
+    /// Stop button transitions Playing → Inactive directly (not via
+    /// Completed). Drive that path and assert no cinephile unlock.
+    #[test]
+    fn cinephile_does_not_unlock_on_stop_button_abort() {
+        let mut app = cinephile_app();
+
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Playing {
+                replay: dummy_replay(),
+                cursor: 0,
+                secs_to_next: 0.0,
+            };
+        app.update();
+
+        // Direct Playing → Inactive — the path the Stop button takes via
+        // `stop_replay_playback`. Must not unlock cinephile.
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Inactive;
+        app.update();
+
+        assert!(
+            !cinephile_unlocked(&app),
+            "Stop button (Playing → Inactive) must not unlock cinephile",
+        );
+        assert_eq!(
+            cinephile_unlocks_emitted(&app),
+            0,
+            "no AchievementUnlockedEvent for cinephile on a Stop transition",
+        );
+    }
+
+    /// A second Playing → Completed cycle on an already-unlocked record
+    /// must be idempotent: no additional `AchievementUnlockedEvent`.
+    #[test]
+    fn cinephile_does_not_double_fire() {
+        let mut app = cinephile_app();
+
+        // First completion cycle to unlock.
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Playing {
+                replay: dummy_replay(),
+                cursor: 0,
+                secs_to_next: 0.0,
+            };
+        app.update();
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Completed;
+        app.update();
+        assert!(cinephile_unlocked(&app), "precondition: first cycle must unlock");
+
+        // Drain the event queue so the next assertion doesn't double-count
+        // the legitimate first-time unlock event.
+        app.world_mut()
+            .resource_mut::<Messages<AchievementUnlockedEvent>>()
+            .clear();
+
+        // Second cycle: Inactive → Playing → Completed once more.
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Inactive;
+        app.update();
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Playing {
+                replay: dummy_replay(),
+                cursor: 0,
+                secs_to_next: 0.0,
+            };
+        app.update();
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Completed;
+        app.update();
+
+        assert_eq!(
+            cinephile_unlocks_emitted(&app),
+            0,
+            "cinephile must not re-fire on a second Playing → Completed cycle",
+        );
+    }
+
+    /// `Completed` lingers across multiple frames before the auto-clear
+    /// transitions back to `Inactive`. The observer must fire exactly
+    /// once during that linger window — not once per frame.
+    #[test]
+    fn cinephile_fires_once_across_completed_linger() {
+        let mut app = cinephile_app();
+
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Playing {
+                replay: dummy_replay(),
+                cursor: 0,
+                secs_to_next: 0.0,
+            };
+        app.update();
+        *app.world_mut().resource_mut::<ReplayPlaybackState>() =
+            ReplayPlaybackState::Completed;
+        app.update();
+        // Stay in Completed for a few more frames as the real auto-clear
+        // does. Each subsequent frame the resource is still `Completed`
+        // but the observer has already counted this transition.
+        app.update();
+        app.update();
+        app.update();
+
+        assert_eq!(
+            cinephile_unlocks_emitted(&app),
+            1,
+            "cinephile must fire exactly once across the Completed linger window",
+        );
+    }
+
     #[test]
     fn no_win_event_means_no_achievement_onboarding_toast() {
         let mut app = onboarding_test_app();

solitaire_engine/src/assets/mod.rs

@@ -11,8 +11,8 @@ pub mod svg_loader;
 pub mod user_dir;
 
 pub use sources::{
-    populate_embedded_default_theme, register_theme_asset_sources, AssetSourcesPlugin,
+    default_theme_svg_bytes, populate_embedded_default_theme, register_theme_asset_sources,
-    DEFAULT_THEME_MANIFEST_URL, USER_THEMES,
+    AssetSourcesPlugin, DEFAULT_THEME_MANIFEST_URL, USER_THEMES,
 };
 pub use svg_loader::{rasterize_svg, SvgLoader, SvgLoaderError, SvgLoaderSettings};
 pub use user_dir::{set_user_theme_dir, user_theme_dir};

solitaire_engine/src/assets/sources.rs

@@ -194,6 +194,25 @@ impl Plugin for AssetSourcesPlugin {
     }
 }
 
+/// Returns the embedded SVG bytes for a single default-theme file
+/// (e.g. `"back.svg"` or `"spades_ace.svg"`), or `None` when the
+/// filename is not bundled.
+///
+/// The thumbnail generator in
+/// [`crate::theme::ThemeThumbnailCache`] uses this to rasterise
+/// preview-sized art for the picker UI without going through Bevy's
+/// async asset graph. Lookup is by the filename only — the
+/// `solitaire_engine/assets/themes/default/` prefix is stripped before
+/// comparison so callers don't need to know where the embedded files
+/// live in the binary.
+pub fn default_theme_svg_bytes(filename: &str) -> Option<&'static [u8]> {
+    let suffix = format!("/{filename}");
+    DEFAULT_THEME_SVGS
+        .iter()
+        .find(|(path, _)| path.ends_with(&suffix))
+        .map(|(_, bytes)| *bytes)
+}
+
 /// Pushes every bundled default-theme file into the
 /// [`EmbeddedAssetRegistry`] under its stable URL. Keeping this in a
 /// free function (and not inside the `Plugin::build` body) means the
@@ -291,6 +310,29 @@ mod tests {
         assert_eq!(faces.len(), 52);
     }
 
+    /// `default_theme_svg_bytes` resolves the canonical preview pair
+    /// the thumbnail cache rasterises: `back.svg` and `spades_ace.svg`.
+    /// Both must exist in the embedded table or the picker's preview
+    /// thumbnails would silently fall back to placeholders even for the
+    /// always-present default theme.
+    #[test]
+    fn default_theme_svg_bytes_finds_back_and_ace_of_spades() {
+        assert!(
+            default_theme_svg_bytes("back.svg").is_some(),
+            "default theme must bundle a back.svg"
+        );
+        assert!(
+            default_theme_svg_bytes("spades_ace.svg").is_some(),
+            "default theme must bundle a spades_ace.svg"
+        );
+    }
+
+    #[test]
+    fn default_theme_svg_bytes_returns_none_for_unknown_file() {
+        assert!(default_theme_svg_bytes("nope.svg").is_none());
+        assert!(default_theme_svg_bytes("").is_none());
+    }
+
     /// Belt-and-braces: if anyone edits `DEFAULT_THEME_MANIFEST_PATH`
     /// without updating `DEFAULT_THEME_MANIFEST_URL` (or vice versa)
     /// the asset would register at one path and be loaded from

solitaire_engine/src/game_plugin.rs

@@ -10,9 +10,17 @@ use std::path::PathBuf;
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use bevy::prelude::*;
-use solitaire_core::game_state::{DrawMode, GameState};
+use chrono::Utc;
-use solitaire_data::{delete_game_state_at, game_state_file_path, load_game_state_from,
+use solitaire_core::game_state::{DrawMode, GameMode, GameState};
-    save_game_state_to};
+use solitaire_core::pile::PileType;
+use solitaire_core::solver::{try_solve, SolverConfig, SolverResult};
+use solitaire_data::{
+    append_replay_to_history, delete_game_state_at, game_state_file_path, load_game_state_from,
+    migrate_legacy_latest_replay, replay_history_path, save_game_state_to, Replay, ReplayMove,
+    SOLVER_DEAL_RETRY_CAP,
+};
+#[allow(deprecated)]
+use solitaire_data::latest_replay_path;
 
 use crate::events::{
     CardFlippedEvent, DrawRequestEvent, FoundationCompletedEvent, GameWonEvent, InfoToastEvent,
@@ -52,6 +60,40 @@ pub struct GameMutation;
 #[derive(Resource, Debug, Clone)]
 pub struct GameStatePath(pub Option<PathBuf>);
 
+/// Persistence path for the rolling [`solitaire_data::ReplayHistory`]
+/// file (`replays.json`). `None` disables I/O — used by tests and on
+/// minimal Linux containers without `dirs::data_dir()`.
+///
+/// Each `GameWonEvent` appends the freshly-frozen [`Replay`] to the
+/// history at this path via
+/// [`solitaire_data::append_replay_to_history`], capping at
+/// [`solitaire_data::REPLAY_HISTORY_CAP`] so the file never grows
+/// unbounded.
+#[derive(Resource, Debug, Clone)]
+pub struct ReplayPath(pub Option<PathBuf>);
+
+/// In-memory accumulator for [`ReplayMove`] entries during the current
+/// game. Cleared on every new-game start; frozen into a [`Replay`] and
+/// flushed to disk by [`record_replay_on_win`] when the player wins.
+///
+/// Recording captures only successful state-mutating events the player
+/// drove (`MoveRequestEvent`, `DrawRequestEvent`). `UndoRequestEvent` is
+/// intentionally not recorded — see [`solitaire_data::replay`] for the
+/// design rationale.
+#[derive(Resource, Debug, Default, Clone)]
+pub struct RecordingReplay {
+    /// Ordered list of moves applied so far this game.
+    pub moves: Vec<ReplayMove>,
+}
+
+impl RecordingReplay {
+    /// Reset the recording. Called on every `NewGameRequestEvent` so a
+    /// fresh deal starts with an empty move list.
+    pub fn clear(&mut self) {
+        self.moves.clear();
+    }
+}
+
 /// Registers game resources, events, and the systems that route user intent
 /// (events) into mutations on `GameState`.
 pub struct GamePlugin;
@@ -73,8 +115,28 @@ impl Plugin for GamePlugin {
             .and_then(load_game_state_from)
             .unwrap_or_else(|| GameState::new(seed_from_system_time(), DrawMode::DrawOne));
 
+        // One-shot migration from the legacy single-slot
+        // `latest_replay.json` to the rolling history at `replays.json`.
+        // Runs at plugin construction so the player's last winning
+        // replay from a pre-history build is the first entry of the
+        // new history file. The legacy file is intentionally left in
+        // place for one release as a safety net (see
+        // `migrate_legacy_latest_replay` doc comment).
+        let history_path = replay_history_path();
+        if let (Some(legacy), Some(history)) =
+            (
+                #[allow(deprecated)]
+                latest_replay_path(),
+                history_path.as_ref(),
+            )
+        {
+            migrate_legacy_latest_replay(&legacy, history);
+        }
+
         app.insert_resource(GameStateResource(initial_state))
             .insert_resource(GameStatePath(path))
+            .insert_resource(ReplayPath(history_path))
+            .init_resource::<RecordingReplay>()
             .init_resource::<DragState>()
             .init_resource::<SyncStatusResource>()
             .add_message::<MoveRequestEvent>()
@@ -100,6 +162,7 @@ impl Plugin for GamePlugin {
                     .in_set(GameMutation),
             )
             .add_systems(Update, check_no_moves.after(GameMutation))
+            .add_systems(Update, record_replay_on_win.after(GameMutation))
             .add_systems(Update, handle_confirm_input.after(GameMutation))
             .add_systems(Update, handle_confirm_button_input.after(GameMutation))
             .add_systems(Update, handle_game_over_input.after(GameMutation))
@@ -157,17 +220,55 @@ fn seed_from_system_time() -> u64 {
         .map_or(0, |d| d.as_nanos() as u64)
 }
 
+/// Walks forward from `initial_seed` (incrementing by 1 with wrapping
+/// arithmetic) until the [`solitaire_core::solver`] returns a verdict
+/// the engine accepts as winnable, or until [`SOLVER_DEAL_RETRY_CAP`]
+/// attempts have elapsed.
+///
+/// The solver classifies each deal as one of three verdicts:
+///   - [`SolverResult::Winnable`] — provably solvable; accept.
+///   - [`SolverResult::Inconclusive`] — budget exceeded, no proof
+///     either way; accept (we treat "we don't know" as winnable so
+///     the toggle never silently drops a player into the retry cap).
+///   - [`SolverResult::Unwinnable`] — provably dead; try the next seed.
+///
+/// If every seed in the retry window is `Unwinnable` (extremely
+/// unlikely on real inputs), the function returns the *last* tried
+/// seed so the player still gets a deal — better a possibly-unwinnable
+/// hand than an infinite loop.
+///
+/// Pure helper extracted for testability — `new_game_with_solver_*`
+/// engine tests in the same file exercise this path.
+pub(crate) fn choose_winnable_seed(initial_seed: u64, draw_mode: &DrawMode) -> u64 {
+    let cfg = SolverConfig::default();
+    let mut seed = initial_seed;
+    for _ in 0..SOLVER_DEAL_RETRY_CAP {
+        match try_solve(seed, draw_mode.clone(), &cfg) {
+            SolverResult::Winnable | SolverResult::Inconclusive => return seed,
+            SolverResult::Unwinnable => {
+                seed = seed.wrapping_add(1);
+            }
+        }
+    }
+    // Retry cap exhausted — accept the latest tried seed rather than
+    // recurring forever.
+    seed
+}
+
 #[allow(clippy::too_many_arguments)]
 fn handle_new_game(
     mut commands: Commands,
     mut new_game: MessageReader<NewGameRequestEvent>,
     mut game: ResMut<GameStateResource>,
     mut changed: MessageWriter<StateChangedEvent>,
+    mut recording: ResMut<RecordingReplay>,
     settings: Option<Res<crate::settings_plugin::SettingsResource>>,
     path: Option<Res<GameStatePath>>,
     font_res: Option<Res<FontResource>>,
     confirm_screens: Query<Entity, With<ConfirmNewGameScreen>>,
     game_over_screens: Query<Entity, With<GameOverScreen>>,
+    layout: Option<Res<crate::layout::LayoutResource>>,
+    mut card_transforms: Query<&mut Transform, With<crate::card_plugin::CardEntity>>,
 ) {
     for ev in new_game.read() {
         // If an active game is in progress, intercept and show a confirm dialog.
@@ -195,7 +296,7 @@ fn handle_new_game(
             commands.entity(entity).despawn();
         }
 
-        let seed = ev.seed.unwrap_or_else(seed_from_system_time);
+        let initial_seed = ev.seed.unwrap_or_else(seed_from_system_time);
         // Prefer the draw mode from Settings when starting a fresh game.
         // Fall back to the current game's draw mode in headless/test contexts
         // where SettingsPlugin is not installed.
@@ -203,12 +304,59 @@ fn handle_new_game(
             .as_ref()
             .map_or_else(|| game.0.draw_mode.clone(), |s| s.0.draw_mode.clone());
         let mode = ev.mode.unwrap_or(game.0.mode);
-        game.0 = GameState::new_with_mode(seed, draw_mode, mode);
+
+        // Solver-backed retry: when the player has opted in to
+        // "Winnable deals only" AND this is a random Classic deal
+        // (no caller-supplied seed), reject deals the solver can
+        // prove unwinnable and try the next seed. Capped at
+        // [`SOLVER_DEAL_RETRY_CAP`] so a pathological run can't
+        // hang the main thread — if every attempt is rejected we
+        // fall through to the latest tried seed.
+        //
+        // **Scope** — the retry deliberately skips:
+        // - Daily challenges and challenge-mode seeds (caller passes
+        //   `ev.seed = Some(...)` so the player gets the same deal as
+        //   everyone else).
+        // - Replays (the replay's own seed is authoritative).
+        // - Any other explicit seed request — the player asked for
+        //   that seed; honour it.
+        let winnable_only = settings
+            .as_ref()
+            .is_some_and(|s| s.0.winnable_deals_only);
+        let chosen_seed = if winnable_only && mode == GameMode::Classic && ev.seed.is_none() {
+            choose_winnable_seed(initial_seed, &draw_mode)
+        } else {
+            initial_seed
+        };
+
+        game.0 = GameState::new_with_mode(chosen_seed, draw_mode, mode);
+        // Reset the in-flight replay buffer — a fresh deal starts with
+        // an empty move list. The previously saved replay on disk
+        // (latest_replay.json) is preserved until the player wins again.
+        recording.clear();
         // Delete any previously saved in-progress state — this is a fresh game.
         if let Some(p) = path.as_ref().and_then(|r| r.0.as_deref())
             && let Err(e) = delete_game_state_at(p) {
                 warn!("game_state: failed to delete saved game: {e}");
             }
+        // Snap every existing card sprite to the stock position before the
+        // deal animation starts. Without this the per-card slide tween reads
+        // each card's previous-game Transform as its source, which lets a
+        // careful observer track origin points to deduce where face-down
+        // cards came from. Funnelling all sprites through the deck position
+        // hides that information and reads naturally as "dealt from the
+        // deck." Skipped when LayoutResource isn't present (headless tests).
+        if let Some(layout) = layout.as_ref()
+            && let Some(stock) = layout
+                .0
+                .pile_positions
+                .get(&solitaire_core::pile::PileType::Stock)
+        {
+            for mut tx in &mut card_transforms {
+                tx.translation.x = stock.x;
+                tx.translation.y = stock.y;
+            }
+        }
         changed.write(StateChangedEvent);
     }
 }
@@ -361,9 +509,8 @@ fn handle_draw(
     mut game: ResMut<GameStateResource>,
     mut changed: MessageWriter<StateChangedEvent>,
     mut flipped: MessageWriter<CardFlippedEvent>,
+    mut recording: ResMut<RecordingReplay>,
 ) {
-    use solitaire_core::pile::PileType;
-
     for _ in draws.read() {
         // Capture which cards are about to be drawn (top of the stock pile)
         // so we can fire flip events after they land face-up in the waste.
@@ -392,6 +539,13 @@ fn handle_draw(
                 for id in drawn_ids {
                     flipped.write(CardFlippedEvent(id));
                 }
+                // Record the atomic player input. Whether the engine
+                // resolves this to a draw or a waste→stock recycle is
+                // a deterministic function of stock state at the time
+                // the click happens — re-executing on the same starting
+                // deal produces the same effect, so the input alone is
+                // sufficient to recover the move on playback.
+                recording.moves.push(ReplayMove::StockClick);
                 changed.write(StateChangedEvent);
             }
             Err(e) => warn!("draw rejected: {e}"),
@@ -407,10 +561,9 @@ fn handle_move(
     mut won: MessageWriter<GameWonEvent>,
     mut flipped: MessageWriter<crate::events::CardFlippedEvent>,
     mut foundation_done: MessageWriter<FoundationCompletedEvent>,
+    mut recording: ResMut<RecordingReplay>,
     path: Option<Res<GameStatePath>>,
 ) {
-    use solitaire_core::pile::PileType;
-
     for ev in moves.read() {
         let was_won = game.0.is_won;
         // Identify the card that will be exposed (and may flip face-up) by the move.
@@ -426,6 +579,14 @@ fn handle_move(
         });
         match game.0.move_cards(ev.from.clone(), ev.to.clone(), ev.count) {
             Ok(()) => {
+                // Record the move in the in-flight replay buffer. Done
+                // first so the entry is captured even if a subsequent
+                // event-write or pile-lookup happens to bail out below.
+                recording.moves.push(ReplayMove::Move {
+                    from: ev.from.clone(),
+                    to: ev.to.clone(),
+                    count: ev.count,
+                });
                 // Fire flip event if the candidate card is now face-up.
                 if let Some(fid) = flip_candidate_id
                     && game.0.piles.get(&ev.from)
@@ -486,62 +647,110 @@ fn handle_undo(
     }
 }
 
+/// On every `GameWonEvent`, freeze the in-flight [`RecordingReplay`] into
+/// a [`Replay`] tagged with the deal seed/mode, the win's score and
+/// elapsed time, and today's date — then append it to the rolling
+/// [`solitaire_data::ReplayHistory`] at the path `ReplayPath` carries
+/// (tests inject a temp path).
+///
+/// The history is capped at [`solitaire_data::REPLAY_HISTORY_CAP`]
+/// entries; older wins age out automatically when the cap is hit. The
+/// recording buffer is left intact after the win so a subsequent
+/// state-change does not erase the move list before the save completes;
+/// it gets cleared on the next `NewGameRequestEvent`.
+pub fn record_replay_on_win(
+    mut wins: MessageReader<GameWonEvent>,
+    game: Res<GameStateResource>,
+    recording: Res<RecordingReplay>,
+    path: Option<Res<ReplayPath>>,
+) {
+    for ev in wins.read() {
+        // Skip persistence when the recording is empty. This guards
+        // against unrelated tests in other plugins that synthesise a
+        // `GameWonEvent` (e.g. to exercise XP / streak / weekly goal
+        // logic) without driving any actual moves — those wins should
+        // not silently overwrite the developer's real replay file.
+        // A real win always has at least one recorded `Move`.
+        if recording.moves.is_empty() {
+            continue;
+        }
+        let replay = Replay::new(
+            game.0.seed,
+            game.0.draw_mode.clone(),
+            game.0.mode,
+            ev.time_seconds,
+            ev.score,
+            Utc::now().date_naive(),
+            recording.moves.clone(),
+        );
+        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
+            // is still available via the resource for callers that want
+            // to inspect it without going through the disk.
+            continue;
+        };
+        if let Err(e) = append_replay_to_history(p, replay) {
+            warn!("replay: failed to append winning replay to history: {e}");
+        }
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Task #29 — No-moves detection
 // ---------------------------------------------------------------------------
 
-/// Returns `true` if the current game state has at least one legal move.
+/// Returns `true` if the current game state has at least one legal move
+/// that could ever lead to progress.
 ///
-/// Considers:
+/// Considers a card "playable" if it's currently face-up on the top of
-/// - Any non-empty Stock or Waste pile (draw / recycle is always available).
+/// the Waste or any Tableau, OR if it lives in the Stock or Waste pile
-/// - Any face-up card on Waste or Tableau piles that can legally move to any
+/// at all (every card in those piles eventually rotates through the
-///   Foundation or Tableau destination.
+/// Waste's top in both Draw-One and Draw-Three over the course of
+/// recycling). For each such candidate, checks whether it can land on
+/// any Foundation or any Tableau in the current state.
+///
+/// Returns `false` only when *no* card anywhere can land anywhere —
+/// the player can keep drawing through the stock forever and nothing
+/// will ever come of it. This treats "draw cycle with no useful drop"
+/// as a softlock rather than as "legal moves remain", which the
+/// previous heuristic incorrectly did (Quat hit this with 4 cards
+/// remaining and the game just sat there).
 pub fn has_legal_moves(game: &GameState) -> bool {
+    use solitaire_core::card::Card;
     use solitaire_core::pile::PileType;
     use solitaire_core::rules::{can_place_on_foundation, can_place_on_tableau};
 
-    // If stock or waste is non-empty, the player can always draw.
+    let mut sources: Vec<Card> = Vec::new();
-    if !game.piles.get(&PileType::Stock).is_some_and(|p| p.cards.is_empty())
+    for ty in [PileType::Stock, PileType::Waste] {
-        || !game.piles.get(&PileType::Waste).is_some_and(|p| p.cards.is_empty())
+        if let Some(p) = game.piles.get(&ty) {
-    {
+            sources.extend(p.cards.iter().cloned());
-        return true;
+        }
+    }
+    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());
+        }
     }
 
-    // Check each playable source pile.
+    for card in &sources {
-    let sources: Vec<PileType> = {
-        let mut v = vec![PileType::Waste];
-        for i in 0..7_usize {
-            v.push(PileType::Tableau(i));
-        }
-        v
-    };
-
-    for from in &sources {
-        let Some(from_pile) = game.piles.get(from) else { continue };
-        let Some(card) = from_pile.cards.last().filter(|c| c.face_up) else { continue };
-
-        // Check foundation slots.
         for slot in 0..4_u8 {
-            let dest = PileType::Foundation(slot);
+            if let Some(dest) = game.piles.get(&PileType::Foundation(slot))
-            if let Some(dest_pile) = game.piles.get(&dest)
+                && can_place_on_foundation(card, dest)
-                && can_place_on_foundation(card, dest_pile) {
+            {
-                    return true;
+                return true;
-                }
+            }
-        }
+        }
-
+        for i in 0..7_usize {
-        // Check tableau piles.
+            if let Some(dest) = game.piles.get(&PileType::Tableau(i))
-        for i in 0..7_usize {
+                && can_place_on_tableau(card, dest)
-            let dest = PileType::Tableau(i);
+            {
-            if dest == *from {
+                return true;
-                continue;
             }
-            if let Some(dest_pile) = game.piles.get(&dest)
-                && can_place_on_tableau(card, dest_pile) {
-                    return true;
-                }
         }
     }
-
     false
 }
 
@@ -772,8 +981,11 @@ mod tests {
     fn test_app(seed: u64) -> App {
         let mut app = App::new();
         app.add_plugins(MinimalPlugins).add_plugins(GamePlugin);
-        // Disable I/O — tests must not touch the real game state file.
+        // Disable I/O — tests must not touch the real game state file or
+        // the real replay file. Both default to dirs::data_dir() in the
+        // plugin's build path; clearing them keeps tests self-contained.
         app.insert_resource(GameStatePath(None));
+        app.insert_resource(ReplayPath(None));
         // Override the system-time seed with a known value.
         app.world_mut()
             .resource_mut::<GameStateResource>()
@@ -1115,10 +1327,49 @@ mod tests {
     // -----------------------------------------------------------------------
 
     #[test]
-    fn has_legal_moves_returns_true_when_stock_nonempty() {
+    fn has_legal_moves_returns_true_for_fresh_game() {
-        // A fresh game has 24 cards in stock — draw is always available.
+        // A fresh deal always contains at least one playable card —
+        // typically several tableau→tableau opportunities plus any Aces
+        // that surface as a tableau column's bottom card.
         let game = GameState::new(42, DrawMode::DrawOne);
-        assert!(has_legal_moves(&game), "draw is always available when stock is non-empty");
+        assert!(has_legal_moves(&game), "fresh deal must contain at least one legal move");
+    }
+
+    #[test]
+    fn has_legal_moves_returns_false_when_stock_only_holds_unplayable_cards() {
+        // Reproduces Quat's softlock: stock has cards but no card anywhere
+        // (stock or otherwise) can land on any pile. The previous heuristic
+        // returned `true` here because stock was non-empty, so the game
+        // sat there forever instead of declaring softlock.
+        use solitaire_core::card::{Card, Rank, Suit};
+        let mut game = GameState::new(1, DrawMode::DrawOne);
+        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();
+        }
+        game.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        // Fill foundation 0 with Clubs A–10, leaving only J/Q/K of Clubs
+        // as plausible foundation moves; load the stock with cards that
+        // can't land on the empty tableau (anything but a King) and can't
+        // extend foundation 0 (anything but Jack of Clubs).
+        let stock = game.piles.get_mut(&PileType::Stock).unwrap();
+        stock.cards.clear();
+        for r in [Rank::Two, Rank::Three, Rank::Four, Rank::Five] {
+            stock.cards.push(Card { id: 100 + r as u32, suit: Suit::Hearts, rank: r, face_up: false });
+        }
+        let foundation_zero = game.piles.get_mut(&PileType::Foundation(0)).unwrap();
+        for r in [
+            Rank::Ace, Rank::Two, Rank::Three, Rank::Four, Rank::Five,
+            Rank::Six, Rank::Seven, Rank::Eight, Rank::Nine, Rank::Ten,
+        ] {
+            foundation_zero.cards.push(Card { id: r as u32, suit: Suit::Clubs, rank: r, face_up: true });
+        }
+        assert!(
+            !has_legal_moves(&game),
+            "stock cards with no legal landing should count as softlock",
+        );
     }
 
     #[test]
@@ -1636,4 +1887,437 @@ mod tests {
             "no InfoToastEvent must fire on a successful undo"
         );
     }
+
+    // -----------------------------------------------------------------------
+    // Win-game replay recording
+    //
+    // The recording resource captures exactly the player-driven actions
+    // that successfully advanced GameState. On GameWonEvent it freezes
+    // into a Replay (with seed/mode/time/score metadata) and persists.
+    // -----------------------------------------------------------------------
+
+    /// Set up Tableau(0) with a face-up Ace of Clubs that can be moved
+    /// to the empty Foundation(0) — gives us a single deterministic move
+    /// to drive the recording without depending on the dealt layout.
+    fn seed_single_legal_move(app: &mut App) {
+        use solitaire_core::card::{Card, Rank, Suit};
+        let mut gs = app.world_mut().resource_mut::<GameStateResource>();
+        let t0 = gs.0.piles.get_mut(&PileType::Tableau(0)).unwrap();
+        t0.cards.clear();
+        t0.cards.push(Card {
+            id: 999,
+            suit: Suit::Clubs,
+            rank: Rank::Ace,
+            face_up: true,
+        });
+        let f0 = gs.0.piles.get_mut(&PileType::Foundation(0)).unwrap();
+        f0.cards.clear();
+    }
+
+    /// Drive a fresh game through a draw + a tableau→foundation move,
+    /// then assert the recording resource captured both, in order, with
+    /// the correct shape.
+    #[test]
+    fn replay_records_moves_in_order() {
+        let mut app = test_app(42);
+
+        // Move 1: a draw against a non-empty stock.
+        app.world_mut().write_message(DrawRequestEvent);
+        app.update();
+
+        // Move 2: a real card move from tableau to foundation.
+        seed_single_legal_move(&mut app);
+        app.world_mut().write_message(MoveRequestEvent {
+            from: PileType::Tableau(0),
+            to: PileType::Foundation(0),
+            count: 1,
+        });
+        app.update();
+
+        // Move 3: another draw.
+        app.world_mut().write_message(DrawRequestEvent);
+        app.update();
+
+        let recording = app.world().resource::<RecordingReplay>();
+        assert_eq!(
+            recording.moves.len(),
+            3,
+            "recording must capture exactly the three successful actions",
+        );
+        assert!(
+            matches!(recording.moves[0], ReplayMove::StockClick),
+            "first entry must be StockClick, got {:?}",
+            recording.moves[0],
+        );
+        match &recording.moves[1] {
+            ReplayMove::Move { from, to, count } => {
+                assert_eq!(*from, PileType::Tableau(0), "from pile must be Tableau(0)");
+                assert_eq!(*to, PileType::Foundation(0), "to pile must be Foundation(0)");
+                assert_eq!(*count, 1, "single-card move must have count 1");
+            }
+            other => panic!("second entry must be a Move, got {other:?}"),
+        }
+        assert!(
+            matches!(recording.moves[2], ReplayMove::StockClick),
+            "third entry must be StockClick, got {:?}",
+            recording.moves[2],
+        );
+    }
+
+    /// Invalid moves must not appear in the recording — the recording is
+    /// "what successfully happened", not "what was requested".
+    #[test]
+    fn replay_does_not_record_rejected_moves() {
+        let mut app = test_app(42);
+        // Stock → Waste is InvalidDestination; the live engine rejects it.
+        app.world_mut().write_message(MoveRequestEvent {
+            from: PileType::Stock,
+            to: PileType::Waste,
+            count: 1,
+        });
+        app.update();
+
+        let recording = app.world().resource::<RecordingReplay>();
+        assert!(
+            recording.moves.is_empty(),
+            "rejected moves must not enter the recording, got {:?}",
+            recording.moves,
+        );
+    }
+
+    /// Undo intentionally does NOT enter the recording. The replay
+    /// represents the canonical path the player took to win, not the
+    /// missteps that were rolled back.
+    #[test]
+    fn replay_recording_skips_undo() {
+        let mut app = test_app(42);
+        app.world_mut().write_message(DrawRequestEvent);
+        app.update();
+        app.world_mut().write_message(UndoRequestEvent);
+        app.update();
+
+        let recording = app.world().resource::<RecordingReplay>();
+        assert_eq!(
+            recording.moves.len(),
+            1,
+            "only the draw is recorded; the undo does not erase it nor add a new entry",
+        );
+        assert!(matches!(recording.moves[0], ReplayMove::StockClick));
+    }
+
+    /// Starting a new game wipes the recording so the next deal begins
+    /// with a clean buffer.
+    #[test]
+    fn replay_recording_clears_on_new_game() {
+        let mut app = test_app(1);
+        app.world_mut().write_message(DrawRequestEvent);
+        app.update();
+        assert_eq!(
+            app.world().resource::<RecordingReplay>().moves.len(),
+            1,
+            "draw should have been recorded",
+        );
+
+        // Use `confirmed: true` so the request bypasses the
+        // abandon-current-game modal (which fires when move_count > 0)
+        // and goes straight to the new-game branch that clears the
+        // recording. The modal-spawn path is exercised by other tests
+        // in this module.
+        app.world_mut().write_message(NewGameRequestEvent {
+            seed: Some(2),
+            mode: None,
+            confirmed: true,
+        });
+        app.update();
+
+        let recording = app.world().resource::<RecordingReplay>();
+        assert!(
+            recording.moves.is_empty(),
+            "recording must be cleared on new-game start; got {:?}",
+            recording.moves,
+        );
+    }
+
+    /// On `GameWonEvent`, the recording is frozen into a `Replay` and
+    /// appended to the rolling [`solitaire_data::ReplayHistory`]. We
+    /// point `ReplayPath` at a temp file, fake a win, and load the
+    /// history back to assert the just-saved entry sits at the front
+    /// with the metadata + move list intact.
+    #[test]
+    fn replay_recording_freezes_into_replay_on_game_won() {
+        use solitaire_data::load_replay_history_from;
+
+        let path = std::env::temp_dir().join("engine_test_replay_freeze.json");
+        let _ = std::fs::remove_file(&path);
+
+        let mut app = test_app(7654);
+        app.insert_resource(ReplayPath(Some(path.clone())));
+
+        // Push two recorded moves manually so we can verify they survive
+        // the freeze/save round-trip without having to drive a real win.
+        {
+            let mut recording = app.world_mut().resource_mut::<RecordingReplay>();
+            recording.moves.push(ReplayMove::StockClick);
+            recording.moves.push(ReplayMove::Move {
+                from: PileType::Waste,
+                to: PileType::Tableau(2),
+                count: 1,
+            });
+        }
+
+        // Fire the win event the engine emits when the last foundation
+        // completes — `record_replay_on_win` listens for it.
+        app.world_mut().write_message(GameWonEvent {
+            score: 4321,
+            time_seconds: 250,
+        });
+        app.update();
+
+        let history = load_replay_history_from(&path)
+            .expect("a winning replay must be persisted to ReplayPath");
+        assert_eq!(
+            history.replays.len(),
+            1,
+            "fresh history must contain exactly the just-recorded win",
+        );
+        let loaded = &history.replays[0];
+        assert_eq!(loaded.seed, 7654, "seed must match the live game state");
+        assert_eq!(loaded.draw_mode, DrawMode::DrawOne, "draw_mode must be captured");
+        assert_eq!(loaded.final_score, 4321, "final_score must come from the win event");
+        assert_eq!(loaded.time_seconds, 250, "time_seconds must come from the win event");
+        assert_eq!(loaded.moves.len(), 2, "every recorded move must round-trip");
+        assert!(matches!(loaded.moves[0], ReplayMove::StockClick));
+        match &loaded.moves[1] {
+            ReplayMove::Move { from, to, count } => {
+                assert_eq!(*from, PileType::Waste);
+                assert_eq!(*to, PileType::Tableau(2));
+                assert_eq!(*count, 1);
+            }
+            other => panic!("second entry must be a Move, got {other:?}"),
+        }
+
+        let _ = std::fs::remove_file(&path);
+    }
+
+    /// Successive `GameWonEvent`s must accumulate in the rolling
+    /// history rather than overwriting one another. Pre-cap, every win
+    /// joins the front of `history.replays`.
+    #[test]
+    fn replay_recording_appends_to_history_across_wins() {
+        use solitaire_data::load_replay_history_from;
+
+        let path = std::env::temp_dir().join("engine_test_replay_history_append.json");
+        let _ = std::fs::remove_file(&path);
+
+        let mut app = test_app(11);
+        app.insert_resource(ReplayPath(Some(path.clone())));
+
+        // First win.
+        {
+            let mut recording = app.world_mut().resource_mut::<RecordingReplay>();
+            recording.moves.clear();
+            recording.moves.push(ReplayMove::StockClick);
+        }
+        app.world_mut().write_message(GameWonEvent {
+            score: 100,
+            time_seconds: 60,
+        });
+        app.update();
+
+        // Second win — different score so we can distinguish.
+        {
+            let mut recording = app.world_mut().resource_mut::<RecordingReplay>();
+            recording.moves.clear();
+            recording.moves.push(ReplayMove::StockClick);
+            recording.moves.push(ReplayMove::StockClick);
+        }
+        app.world_mut().write_message(GameWonEvent {
+            score: 200,
+            time_seconds: 120,
+        });
+        app.update();
+
+        let history = load_replay_history_from(&path).expect("history must exist");
+        assert_eq!(history.replays.len(), 2, "both wins must be retained");
+        // Newest first — second win lands at index 0.
+        assert_eq!(history.replays[0].final_score, 200);
+        assert_eq!(history.replays[1].final_score, 100);
+
+        let _ = std::fs::remove_file(&path);
+    }
+
+    /// `GameWonEvent` with an empty recording must NOT touch disk.
+    /// Without this guard, parallel-plugin tests that synthesise
+    /// win events for XP / streak / weekly-goal logic (without
+    /// driving any actual moves) would clobber the developer's real
+    /// replay file every time `cargo test` ran.
+    #[test]
+    fn replay_with_empty_recording_skips_save() {
+        let path = std::env::temp_dir().join("engine_test_replay_empty_skip.json");
+        let _ = std::fs::remove_file(&path);
+
+        let mut app = test_app(1);
+        app.insert_resource(ReplayPath(Some(path.clone())));
+        // Recording is empty by default — fire a win event anyway.
+        app.world_mut().write_message(GameWonEvent {
+            score: 100,
+            time_seconds: 30,
+        });
+        app.update();
+
+        assert!(
+            !path.exists(),
+            "no replay must be written when recording is empty",
+        );
+    }
+
+    // -----------------------------------------------------------------------
+    // Solver-backed "Winnable deals only" toggle
+    //
+    // Exercises [`choose_winnable_seed`] and the wiring inside
+    // `handle_new_game` that consults [`Settings::winnable_deals_only`].
+    // -----------------------------------------------------------------------
+
+    /// Inject a `SettingsResource` with the given `winnable_deals_only`
+    /// flag. The handle_new_game system already reads this resource via
+    /// `Option<Res<...>>`, so no `SettingsPlugin` boot is needed.
+    fn insert_settings(app: &mut App, winnable_deals_only: bool) {
+        let settings = solitaire_data::Settings {
+            winnable_deals_only,
+            ..solitaire_data::Settings::default()
+        };
+        app.insert_resource(crate::settings_plugin::SettingsResource(settings));
+    }
+
+    #[test]
+    fn new_game_with_solver_toggle_off_uses_requested_seed() {
+        // Toggle off — the engine must use the seed it was handed and
+        // never invoke the solver. Seed 999 is just an arbitrary
+        // deterministic seed; the test asserts the resulting deal
+        // matches `GameState::new(999, DrawOne)`.
+        let mut app = test_app(1);
+        insert_settings(&mut app, false);
+
+        app.world_mut().write_message(NewGameRequestEvent {
+            seed: Some(999),
+            mode: None,
+            confirmed: false,
+        });
+        app.update();
+
+        let actual_seed = app.world().resource::<GameStateResource>().0.seed;
+        assert_eq!(
+            actual_seed, 999,
+            "with solver toggle off, the requested seed must be honoured exactly"
+        );
+        // Cross-check: the dealt tableau must match GameState::new(999) byte-for-byte.
+        let expected = GameState::new(999, DrawMode::DrawOne);
+        for i in 0..7 {
+            assert_eq!(
+                app.world().resource::<GameStateResource>().0.piles[&PileType::Tableau(i)].cards,
+                expected.piles[&PileType::Tableau(i)].cards,
+                "tableau column {i} must match the unfiltered seed",
+            );
+        }
+    }
+
+    #[test]
+    fn new_game_with_solver_toggle_off_random_seed_path() {
+        // When seed is None and toggle is off, the engine uses a
+        // system-time seed and skips the solver. We can't pin the
+        // exact seed, but we can assert the seed is *not* the
+        // sentinel zero (which would only happen if SystemTime is
+        // before the epoch — practically impossible), AND that no
+        // resource has been mutated to suggest the solver ran.
+        // The strongest assertion is "the move runs to completion
+        // without panicking", which the .update() call covers.
+        let mut app = test_app(1);
+        insert_settings(&mut app, false);
+
+        app.world_mut().write_message(NewGameRequestEvent {
+            seed: None,
+            mode: None,
+            confirmed: false,
+        });
+        app.update();
+
+        // Game state was reseeded — move_count is 0 on the new game.
+        assert_eq!(app.world().resource::<GameStateResource>().0.move_count, 0);
+    }
+
+    #[test]
+    fn new_game_with_solver_toggle_on_skips_solver_for_specific_seed() {
+        // Even with the toggle on, an *explicit* seed must be honoured:
+        // daily challenges, replay seeding, and challenge-mode all
+        // pass `Some(seed)` and must never be retried.
+        let mut app = test_app(1);
+        insert_settings(&mut app, true);
+
+        app.world_mut().write_message(NewGameRequestEvent {
+            seed: Some(123),
+            mode: None,
+            confirmed: false,
+        });
+        app.update();
+
+        assert_eq!(
+            app.world().resource::<GameStateResource>().0.seed,
+            123,
+            "explicit-seed requests must skip the solver retry loop",
+        );
+    }
+
+    #[test]
+    fn choose_winnable_seed_skips_unwinnable_seed() {
+        // Seed 394 was identified by the offline scan
+        // (`solver::tests::find_unwinnable`) as the only Unwinnable
+        // seed in 0..500 under the default solver budget. Seed 395
+        // resolves as Inconclusive — the engine treats Inconclusive
+        // as winnable (see `choose_winnable_seed` doc), so the
+        // helper must return 395 when started at 394.
+        let chosen = choose_winnable_seed(394, &DrawMode::DrawOne);
+        assert_eq!(
+            chosen, 395,
+            "seed 394 is Unwinnable; the next seed (395, Inconclusive) must be accepted"
+        );
+    }
+
+    #[test]
+    fn new_game_with_solver_toggle_on_retries_until_winnable() {
+        // End-to-end: with the toggle on, fire a NewGameRequestEvent
+        // with seed=None and *manually pre-seed* the system-time
+        // path by clearing the GameStateResource so handle_new_game
+        // takes the random branch. We can't easily inject the
+        // system-time seed here, so we exercise the helper via a
+        // separate call and assert the *resource* receives the
+        // post-retry seed when the helper would have rejected.
+        //
+        // We test the integration by setting up an alternative
+        // scenario: pass `seed: Some(394)` with toggle on. Our
+        // implementation already documents that explicit seeds skip
+        // the retry, so this *won't* trigger retry. The cleaner
+        // integration is captured in `choose_winnable_seed_skips_*`.
+        // Here we verify the default-seed path doesn't crash when
+        // toggle is on — exercising the live solver call inside
+        // handle_new_game without depending on the solver picking
+        // a specific seed.
+        let mut app = test_app(1);
+        insert_settings(&mut app, true);
+
+        app.world_mut().write_message(NewGameRequestEvent {
+            seed: None,
+            mode: None,
+            confirmed: false,
+        });
+        app.update();
+
+        // The chosen seed is non-deterministic (system time),
+        // but the new game must have been started cleanly:
+        // move_count back to 0, undo stack empty.
+        assert_eq!(app.world().resource::<GameStateResource>().0.move_count, 0);
+        assert_eq!(
+            app.world().resource::<GameStateResource>().0.undo_stack_len(),
+            0
+        );
+    }
 }

solitaire_engine/src/lib.rs

@@ -24,6 +24,8 @@ pub mod onboarding_plugin;
 pub mod pause_plugin;
 pub mod profile_plugin;
 pub mod radial_menu;
+pub mod replay_overlay;
+pub mod replay_playback;
 pub mod settings_plugin;
 pub mod progress_plugin;
 pub mod resources;
@@ -92,7 +94,10 @@ pub use events::{
     ToggleLeaderboardRequestEvent, ToggleProfileRequestEvent, ToggleSettingsRequestEvent,
     ToggleStatsRequestEvent, UndoRequestEvent, WinStreakMilestoneEvent, XpAwardedEvent,
 };
-pub use game_plugin::{ConfirmNewGameScreen, GameMutation, GameOverScreen, GamePlugin, GameStatePath};
+pub use game_plugin::{
+    ConfirmNewGameScreen, GameMutation, GameOverScreen, GamePlugin, GameStatePath, RecordingReplay,
+    ReplayPath,
+};
 pub use help_plugin::{HelpPlugin, HelpScreen};
 pub use home_plugin::{HomePlugin, HomeScreen};
 pub use hud_plugin::{
@@ -109,6 +114,14 @@ pub use radial_menu::{
     legal_destinations_for_card, radial_anchor_for_index, radial_hovered_index, RadialIcon,
     RadialMenuPlugin, RightClickRadialState, Z_RADIAL_MENU,
 };
+pub use replay_overlay::{
+    ReplayOverlayBannerText, ReplayOverlayPlugin, ReplayOverlayProgressText, ReplayOverlayRoot,
+    ReplayStopButton, Z_REPLAY_OVERLAY,
+};
+pub use replay_playback::{
+    start_replay_playback, stop_replay_playback, ReplayPlaybackPlugin, ReplayPlaybackState,
+    REPLAY_COMPLETION_LINGER_SECS, REPLAY_MOVE_INTERVAL_SECS,
+};
 pub use settings_plugin::{
     PendingWindowGeometry, SettingsChangedEvent, SettingsPlugin, SettingsResource, SettingsScreen,
     SFX_STEP, WINDOW_GEOMETRY_DEBOUNCE_SECS,
@@ -119,7 +132,11 @@ pub use selection_plugin::{
     KeyboardDragState, SelectionHighlight, SelectionPlugin, SelectionState,
 };
 pub use splash_plugin::{SplashAge, SplashPlugin, SplashRoot};
-pub use stats_plugin::{StatsPlugin, StatsResource, StatsScreen, StatsUpdate};
+pub use stats_plugin::{
+    format_replay_caption, LatestReplayPath, ReplayHistoryResource, ReplayNextButton,
+    ReplayPrevButton, ReplaySelectorCaption, SelectedReplayIndex, StatsPlugin, StatsResource,
+    StatsScreen, StatsUpdate, WatchReplayButton,
+};
 pub use sync_plugin::{SyncPlugin, SyncProviderResource};
 pub use ui_focus::{Disabled, FocusGroup, Focusable, FocusedButton, UiFocusPlugin};
 pub use ui_modal::{

solitaire_engine/src/profile_plugin.rs

@@ -6,6 +6,7 @@
 
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
+use chrono::{Duration, Local, NaiveDate};
 use solitaire_core::achievement::achievement_by_id;
 use solitaire_data::SyncBackend;
 
@@ -20,14 +21,38 @@ use crate::ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_button, spawn_modal_header, ButtonVariant,
 };
 use crate::ui_theme::{
-    ACCENT_PRIMARY, STATE_INFO, STATE_SUCCESS, TEXT_PRIMARY, TEXT_SECONDARY, TYPE_BODY,
+    ACCENT_PRIMARY, BG_ELEVATED, BORDER_STRONG, SPACE_1, STATE_INFO, STATE_SUCCESS, TEXT_PRIMARY,
-    TYPE_BODY_LG, VAL_SPACE_2, Z_MODAL_PANEL,
+    TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, VAL_SPACE_1, VAL_SPACE_2, Z_MODAL_PANEL,
 };
 
+/// Number of days surfaced in the daily-challenge calendar row.
+///
+/// 14 = trailing two weeks ending today. At ~12 px per dot with a 6 px gap
+/// the row is ~246 px wide — well inside the 360 px minimum modal width on
+/// the smallest supported window (800 px).
+const CALENDAR_DAYS: usize = 14;
+
+/// Diameter of each calendar dot, in pixels.
+const CALENDAR_DOT_SIZE_PX: f32 = 12.0;
+
 /// Marker component on the profile overlay root node.
 #[derive(Component, Debug)]
 pub struct ProfileScreen;
 
+/// Marker on each daily-challenge calendar dot inside the Profile modal.
+///
+/// One entity per day in the trailing 14-day window — tests can query
+/// for this component to assert the row was rendered.
+#[derive(Component, Debug, Clone, Copy)]
+pub struct DailyCalendarDot {
+    /// The calendar date this dot represents.
+    pub date: NaiveDate,
+    /// Whether the player completed the daily challenge on `date`.
+    pub completed: bool,
+    /// `true` if `date == today` (the rightmost dot).
+    pub is_today: bool,
+}
+
 /// Registers the `P` key toggle for the profile overlay.
 pub struct ProfilePlugin;
 
@@ -195,6 +220,16 @@ fn spawn_profile_screen(
                 font_row.clone(),
                 TextColor(TEXT_PRIMARY),
             ));
+
+            // 14-day daily-challenge calendar row.
+            spawn_daily_calendar(
+                card,
+                &prog.daily_challenge_history,
+                prog.daily_challenge_streak,
+                prog.daily_challenge_longest_streak,
+                Local::now().date_naive(),
+                font_res,
+            );
         }
 
         // ── Achievements section ────────────────────────────────────
@@ -300,6 +335,98 @@ fn spawn_spacer(parent: &mut ChildSpawnerCommands, height: Val) {
     });
 }
 
+/// Spawn the daily-challenge calendar row: a caption + 14 dots.
+///
+/// `history` is the player's full chronological completion history.
+/// `current_streak` and `longest_streak` are surfaced in the caption.
+/// `today` is passed in (rather than read directly) so the function is
+/// trivially testable with a fixed reference date.
+///
+/// Layout: caption row → row of 14 dots (~12 px each, 6 px gap). The
+/// rightmost dot represents today; past dots fill from oldest (left) to
+/// most recent (right). Each dot carries a [`DailyCalendarDot`] marker.
+fn spawn_daily_calendar(
+    parent: &mut ChildSpawnerCommands,
+    history: &[NaiveDate],
+    current_streak: u32,
+    longest_streak: u32,
+    today: NaiveDate,
+    font_res: Option<&FontResource>,
+) {
+    use std::collections::HashSet;
+    let history_set: HashSet<NaiveDate> = history.iter().copied().collect();
+
+    let font_caption = TextFont {
+        font: font_res.map(|f| f.0.clone()).unwrap_or_default(),
+        font_size: TYPE_CAPTION,
+        ..default()
+    };
+
+    parent.spawn((
+        Text::new(format!(
+            "Current streak: {current_streak}  \u{00B7}  Longest: {longest_streak}"
+        )),
+        font_caption,
+        TextColor(TEXT_SECONDARY),
+        Node {
+            margin: UiRect {
+                top: VAL_SPACE_1,
+                bottom: VAL_SPACE_1,
+                ..default()
+            },
+            ..default()
+        },
+    ));
+
+    parent
+        .spawn(Node {
+            flex_direction: FlexDirection::Row,
+            column_gap: Val::Px(SPACE_1 + 2.0), // 6 px between dots
+            align_items: AlignItems::Center,
+            ..default()
+        })
+        .with_children(|row| {
+            // Iterate from oldest (today − 13) to today (rightmost).
+            for offset in (0..CALENDAR_DAYS as i64).rev() {
+                let date = today - Duration::days(offset);
+                let is_today = offset == 0;
+                let completed = history_set.contains(&date);
+                // Today's dot keeps the outlined-ring look (Balatro-yellow
+                // accent border) regardless of completion; past days use a
+                // subtle border so the row reads as a row of pills, not a
+                // strip of bare squares.
+                let border_color = if is_today { ACCENT_PRIMARY } else { BORDER_STRONG };
+                let border_width = if is_today { 2.0 } else { 0.0 };
+                row.spawn((
+                    DailyCalendarDot {
+                        date,
+                        completed,
+                        is_today,
+                    },
+                    Node {
+                        width: Val::Px(CALENDAR_DOT_SIZE_PX),
+                        height: Val::Px(CALENDAR_DOT_SIZE_PX),
+                        border: UiRect::all(Val::Px(border_width)),
+                        border_radius: BorderRadius::all(Val::Px(CALENDAR_DOT_SIZE_PX / 2.0)),
+                        ..default()
+                    },
+                    BackgroundColor(calendar_dot_color(completed)),
+                    BorderColor::all(border_color),
+                ));
+            }
+        });
+}
+
+/// Background colour for a calendar dot. `STATE_SUCCESS` for completed
+/// days, `BG_ELEVATED` for missed/pending days.
+fn calendar_dot_color(completed: bool) -> Color {
+    if completed {
+        STATE_SUCCESS
+    } else {
+        BG_ELEVATED
+    }
+}
+
 /// Return `(backend_name, username_display)` for the given sync backend.
 fn sync_info(backend: &SyncBackend) -> (&'static str, String) {
     match backend {
@@ -417,4 +544,43 @@ mod tests {
         // Level 10 is the first post-table level (span = 1000, starts at 5000).
         assert_eq!(xp_progress(5_000, 10), (1_000, 0));
     }
+
+    #[test]
+    fn profile_modal_renders_14_calendar_dots() {
+        // Open the Profile modal and assert the 14-day calendar row was
+        // populated with one DailyCalendarDot entity per day.
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyP);
+        app.update();
+
+        let dot_count = app
+            .world_mut()
+            .query::<&DailyCalendarDot>()
+            .iter(app.world())
+            .count();
+        assert_eq!(
+            dot_count, CALENDAR_DAYS,
+            "Profile modal must render exactly {CALENDAR_DAYS} calendar dots"
+        );
+    }
+
+    #[test]
+    fn calendar_dot_today_marker_is_set_on_rightmost_dot_only() {
+        // Exactly one of the 14 dots is the "today" dot (the rightmost).
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyP);
+        app.update();
+
+        let today_count = app
+            .world_mut()
+            .query::<&DailyCalendarDot>()
+            .iter(app.world())
+            .filter(|d| d.is_today)
+            .count();
+        assert_eq!(today_count, 1, "exactly one dot must be marked is_today");
+    }
 }

solitaire_engine/src/replay_overlay.rs

@@ -0,0 +1,565 @@
+//! On-screen overlay shown while a recorded [`Replay`] plays back.
+//!
+//! The overlay is a thin top-of-window banner with three pieces of UI:
+//!
+//! - A "Replay" label on the left so the player knows the surface is
+//!   under playback control rather than live input.
+//! - A "Move N of M" progress indicator in the centre, recomputed every
+//!   frame the cursor advances.
+//! - A "Stop" button on the right that aborts playback and returns
+//!   control to the player.
+//!
+//! When playback finishes ([`ReplayPlaybackState::Completed`]) the banner
+//! label swaps to "Replay complete" and stays visible until the playback
+//! core auto-clears the resource back to [`ReplayPlaybackState::Inactive`]
+//! a few seconds later, at which point the overlay despawns.
+//!
+//! The overlay sits at z-layer [`Z_REPLAY_OVERLAY`] — above gameplay but
+//! below every modal layer ([`Z_MODAL_SCRIM`] and up). That ordering lets
+//! the player still open Settings, Pause, and Help during a replay; those
+//! modals will render on top of the banner as expected.
+//!
+//! [`Replay`]: solitaire_data::Replay
+//! [`Z_MODAL_SCRIM`]: crate::ui_theme::Z_MODAL_SCRIM
+
+use bevy::prelude::*;
+
+use crate::font_plugin::FontResource;
+use crate::replay_playback::{stop_replay_playback, ReplayPlaybackState};
+use crate::ui_modal::{spawn_modal_button, ButtonVariant};
+use crate::ui_theme::{
+    ACCENT_PRIMARY, BG_ELEVATED_HI, TEXT_PRIMARY, TYPE_BODY, TYPE_HEADLINE, VAL_SPACE_2,
+    VAL_SPACE_4, Z_DROP_OVERLAY,
+};
+
+// ---------------------------------------------------------------------------
+// Z-index — see `ui_theme::Z_MODAL_SCRIM` (200) for the next layer above.
+// ---------------------------------------------------------------------------
+
+/// `bevy::ui` `ZIndex` value for the replay overlay banner.
+///
+/// Numeric value is `Z_DROP_OVERLAY as i32 + 5 = 55`; chosen so the banner
+/// sits clearly above the HUD top layer (`Z_HUD_TOP = 60` is intentionally
+/// **below** modals, but the overlay needs to be above HUD readouts) yet
+/// well below `Z_MODAL_SCRIM = 200` so Settings, Pause, and Help modals
+/// continue to render on top of the overlay during a replay.
+///
+/// The `Z_DROP_OVERLAY + 5` formula in the spec is reproduced here as an
+/// integer because `Z_DROP_OVERLAY` itself is a `f32` Sprite-space z used
+/// for the drop-target overlay sprites — UI nodes use `i32` `ZIndex`, so
+/// we materialise a separate constant rather than reuse the `f32` value.
+pub const Z_REPLAY_OVERLAY: i32 = Z_DROP_OVERLAY as i32 + 5;
+
+/// Total height of the banner in pixels. Thin enough to leave the
+/// gameplay surface visible underneath, tall enough to comfortably fit
+/// the headline-sized "Replay" label.
+const BANNER_HEIGHT: f32 = 48.0;
+
+/// Background colour alpha for the banner. `BG_ELEVATED_HI` at this alpha
+/// reads as a clear "this is a UI strip" callout while still letting the
+/// felt show through enough to anchor the banner to the play surface.
+const BANNER_ALPHA: f32 = 0.92;
+
+// ---------------------------------------------------------------------------
+// Marker components
+// ---------------------------------------------------------------------------
+
+/// Marker on the banner's root `Node`. Used by the spawn / despawn /
+/// progress-update systems to find the overlay.
+#[derive(Component, Debug)]
+pub struct ReplayOverlayRoot;
+
+/// Marker on the left-hand banner label `Text`. Carries either "Replay"
+/// (during playback) or "Replay complete" (once finished); the
+/// completion-text-update system swaps the contents in place.
+#[derive(Component, Debug)]
+pub struct ReplayOverlayBannerText;
+
+/// Marker on the centre progress `Text`. Updated every frame to reflect
+/// the current `(cursor, total)` returned by
+/// [`ReplayPlaybackState::progress`].
+#[derive(Component, Debug)]
+pub struct ReplayOverlayProgressText;
+
+/// Marker on the right-hand "Stop" button. Click handler queries for this
+/// and calls [`stop_replay_playback`] when an `Interaction::Pressed`
+/// transition is seen.
+#[derive(Component, Debug)]
+pub struct ReplayStopButton;
+
+// ---------------------------------------------------------------------------
+// Plugin
+// ---------------------------------------------------------------------------
+
+/// Bevy plugin that registers every system needed to drive the replay
+/// overlay's lifecycle.
+///
+/// The plugin is independent of [`crate::replay_playback::ReplayPlaybackPlugin`]
+/// — it only reads the shared `ReplayPlaybackState` resource. Tests insert
+/// the resource manually and exercise the overlay in isolation.
+pub struct ReplayOverlayPlugin;
+
+impl Plugin for ReplayOverlayPlugin {
+    fn build(&self, app: &mut App) {
+        // The systems are ordered so that, on a single frame:
+        //   1. The state-watcher spawns or despawns the overlay if the
+        //      `ReplayPlaybackState` resource changed.
+        //   2. The completion-text update swaps the banner label when the
+        //      state is `Completed`.
+        //   3. The progress-text update writes the latest "Move N of M".
+        //   4. The Stop-button click handler reads `Interaction::Pressed`
+        //      and calls `stop_replay_playback` (which mutates the state).
+        // Putting Stop last means a click in frame N is observed by
+        // `react_to_state_change` in frame N+1, which then despawns the
+        // overlay in response — a clean state-driven loop.
+        app.add_systems(
+            Update,
+            (
+                react_to_state_change,
+                update_banner_label,
+                update_progress_text,
+                handle_stop_button,
+            )
+                .chain(),
+        );
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Spawning
+// ---------------------------------------------------------------------------
+
+/// Reads [`ReplayPlaybackState`] every time the resource changes and either
+/// spawns or despawns the overlay accordingly. Treats the resource as the
+/// single source of truth — the spawn / despawn decision is derived from
+/// `is_playing() || is_completed()` rather than tracking previous-state
+/// transitions explicitly, which keeps the system stateless.
+fn react_to_state_change(
+    mut commands: Commands,
+    state: Res<ReplayPlaybackState>,
+    existing: Query<Entity, With<ReplayOverlayRoot>>,
+    font_res: Option<Res<FontResource>>,
+) {
+    if !state.is_changed() {
+        return;
+    }
+
+    let should_be_visible = state.is_playing() || state.is_completed();
+    let already_spawned = existing.iter().next().is_some();
+
+    if should_be_visible && !already_spawned {
+        spawn_overlay(&mut commands, font_res.as_deref(), &state);
+    } else if !should_be_visible && already_spawned {
+        for entity in &existing {
+            commands.entity(entity).despawn();
+        }
+    }
+    // The `should_be_visible && already_spawned` branch is a no-op here —
+    // the per-frame text update systems below repaint the banner label
+    // and progress readout in place without a respawn.
+}
+
+/// Spawns the banner — a flex-row Node anchored to the top edge of the
+/// window with three children: the "Replay" / "Replay complete" label,
+/// the centred progress text, and the right-aligned Stop button.
+fn spawn_overlay(
+    commands: &mut Commands,
+    font_res: Option<&FontResource>,
+    state: &ReplayPlaybackState,
+) {
+    let font_handle = font_res.map(|f| f.0.clone()).unwrap_or_default();
+
+    let banner_label = if state.is_completed() {
+        "Replay complete"
+    } else {
+        "Replay"
+    };
+    let progress_label = format_progress(state);
+
+    let banner_bg = Color::srgba(
+        BG_ELEVATED_HI.to_srgba().red,
+        BG_ELEVATED_HI.to_srgba().green,
+        BG_ELEVATED_HI.to_srgba().blue,
+        BANNER_ALPHA,
+    );
+
+    commands
+        .spawn((
+            ReplayOverlayRoot,
+            Node {
+                position_type: PositionType::Absolute,
+                left: Val::Px(0.0),
+                top: Val::Px(0.0),
+                width: Val::Percent(100.0),
+                height: Val::Px(BANNER_HEIGHT),
+                flex_direction: FlexDirection::Row,
+                align_items: AlignItems::Center,
+                justify_content: JustifyContent::SpaceBetween,
+                padding: UiRect::axes(VAL_SPACE_4, VAL_SPACE_2),
+                column_gap: VAL_SPACE_4,
+                ..default()
+            },
+            BackgroundColor(banner_bg),
+            // Pin the banner to its z layer in both the local and the
+            // global stacking context — `GlobalZIndex` matters because
+            // the overlay is a top-level Node (no parent), and Bevy 0.18
+            // has historically had subtle stacking-context drift here.
+            ZIndex(Z_REPLAY_OVERLAY),
+            GlobalZIndex(Z_REPLAY_OVERLAY),
+        ))
+        .with_children(|banner| {
+            // Left: "Replay" label in the loud yellow accent so it reads
+            // unmistakably as a non-gameplay surface.
+            banner.spawn((
+                ReplayOverlayBannerText,
+                Text::new(banner_label),
+                TextFont {
+                    font: font_handle.clone(),
+                    font_size: TYPE_HEADLINE,
+                    ..default()
+                },
+                TextColor(ACCENT_PRIMARY),
+            ));
+
+            // Centre: progress readout — neutral primary text colour so
+            // the eye treats it as data, not a callout.
+            banner.spawn((
+                ReplayOverlayProgressText,
+                Text::new(progress_label),
+                TextFont {
+                    font: font_handle,
+                    font_size: TYPE_BODY,
+                    ..default()
+                },
+                TextColor(TEXT_PRIMARY),
+            ));
+
+            // Right: Stop button. Tertiary variant — the action is
+            // available but not the loudest element in the banner; the
+            // "Replay" yellow accent owns that slot. `spawn_modal_button`
+            // gives us hover / press paint and focus rings for free via
+            // the existing `UiModalPlugin` paint system.
+            banner
+                .spawn(Node {
+                    flex_direction: FlexDirection::Row,
+                    align_items: AlignItems::Center,
+                    column_gap: VAL_SPACE_2,
+                    ..default()
+                })
+                .with_children(|wrap| {
+                    spawn_modal_button(
+                        wrap,
+                        ReplayStopButton,
+                        "Stop",
+                        None,
+                        ButtonVariant::Tertiary,
+                        font_res,
+                    );
+                });
+        });
+}
+
+// ---------------------------------------------------------------------------
+// Per-frame text updates
+// ---------------------------------------------------------------------------
+
+/// Overwrites the banner label whenever the resource changes — covers the
+/// `Playing → Completed` transition by swapping "Replay" for
+/// "Replay complete" in place without despawning the overlay.
+fn update_banner_label(
+    state: Res<ReplayPlaybackState>,
+    mut q: Query<&mut Text, With<ReplayOverlayBannerText>>,
+) {
+    if !state.is_changed() {
+        return;
+    }
+    let label = if state.is_completed() {
+        "Replay complete"
+    } else if state.is_playing() {
+        "Replay"
+    } else {
+        return;
+    };
+    for mut text in &mut q {
+        **text = label.to_string();
+    }
+}
+
+/// Repaints the "Move N of M" centre readout every frame the cursor moves.
+/// Cheap — early-exits if the resource has not changed since the last
+/// frame so idle replays don't churn the text mesh.
+fn update_progress_text(
+    state: Res<ReplayPlaybackState>,
+    mut q: Query<&mut Text, With<ReplayOverlayProgressText>>,
+) {
+    if !state.is_changed() {
+        return;
+    }
+    let label = format_progress(&state);
+    for mut text in &mut q {
+        **text = label.clone();
+    }
+}
+
+/// Pure helper — formats the centre progress readout for the given state.
+/// Exposed at module scope so the spawn path and the per-frame update
+/// path produce the exact same string.
+fn format_progress(state: &ReplayPlaybackState) -> String {
+    match state.progress() {
+        Some((cursor, total)) => format!("Move {cursor} of {total}"),
+        None if state.is_completed() => "Replay complete".to_string(),
+        None => String::new(),
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Stop button handler
+// ---------------------------------------------------------------------------
+
+/// Watches the Stop button for `Interaction::Pressed` transitions. On a
+/// click, calls [`stop_replay_playback`] which resets the state to
+/// `Inactive`; the next frame's `react_to_state_change` then despawns
+/// the overlay.
+fn handle_stop_button(
+    mut commands: Commands,
+    mut state: ResMut<ReplayPlaybackState>,
+    buttons: Query<&Interaction, (With<ReplayStopButton>, Changed<Interaction>)>,
+) {
+    if !buttons.iter().any(|i| *i == Interaction::Pressed) {
+        return;
+    }
+    stop_replay_playback(&mut commands, &mut state);
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::NaiveDate;
+    use solitaire_core::game_state::{DrawMode, GameMode};
+    use solitaire_data::{Replay, ReplayMove};
+
+    /// Build a minimal but well-formed [`Replay`] with `move_count` no-op
+    /// `StockClick` entries. Tests only ever read `replay.moves.len()`
+    /// (denominator of the progress indicator), so the move kind is
+    /// irrelevant beyond producing the right count.
+    fn synthetic_replay(move_count: usize) -> Replay {
+        Replay::new(
+            42,
+            DrawMode::DrawOne,
+            GameMode::Classic,
+            120,
+            1_000,
+            NaiveDate::from_ymd_opt(2026, 5, 2).expect("valid date"),
+            (0..move_count).map(|_| ReplayMove::StockClick).collect(),
+        )
+    }
+
+    /// Build a test app that has the overlay plugin but **not** the
+    /// playback plugin — tests insert `ReplayPlaybackState` manually so
+    /// they can drive every state transition deterministically.
+    fn headless_app() -> App {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins).add_plugins(ReplayOverlayPlugin);
+        app.init_resource::<ReplayPlaybackState>();
+        app
+    }
+
+    /// Count `ReplayOverlayRoot` entities in the world — the overlay's
+    /// presence/absence is the spawn-test's primary observable.
+    fn overlay_root_count(app: &mut App) -> usize {
+        app.world_mut()
+            .query::<&ReplayOverlayRoot>()
+            .iter(app.world())
+            .count()
+    }
+
+    /// Read the current text content of the unique progress-text entity.
+    fn progress_text(app: &mut App) -> String {
+        let mut q = app
+            .world_mut()
+            .query_filtered::<&Text, With<ReplayOverlayProgressText>>();
+        q.iter(app.world())
+            .next()
+            .map(|t| t.0.clone())
+            .unwrap_or_default()
+    }
+
+    /// Read the current text content of the unique banner-label entity.
+    fn banner_text(app: &mut App) -> String {
+        let mut q = app
+            .world_mut()
+            .query_filtered::<&Text, With<ReplayOverlayBannerText>>();
+        q.iter(app.world())
+            .next()
+            .map(|t| t.0.clone())
+            .unwrap_or_default()
+    }
+
+    /// Set the playback resource without going through the playback core.
+    fn set_state(app: &mut App, state: ReplayPlaybackState) {
+        app.world_mut().insert_resource(state);
+    }
+
+    /// Find the unique `ReplayStopButton` entity for the click-handler
+    /// test. There must be exactly one.
+    fn stop_button_entity(app: &mut App) -> Entity {
+        let mut q = app
+            .world_mut()
+            .query_filtered::<Entity, With<ReplayStopButton>>();
+        q.iter(app.world())
+            .next()
+            .expect("Stop button must exist while overlay is spawned")
+    }
+
+    /// Going `Inactive → Playing` spawns exactly one overlay root and
+    /// the banner label reads "Replay".
+    #[test]
+    fn overlay_spawns_when_playback_starts() {
+        let mut app = headless_app();
+        // First update with the default `Inactive` resource — overlay
+        // must not exist yet.
+        app.update();
+        assert_eq!(overlay_root_count(&mut app), 0);
+
+        set_state(
+            &mut app,
+            ReplayPlaybackState::Playing {
+                replay: synthetic_replay(10),
+                cursor: 0,
+                secs_to_next: 0.5,
+            },
+        );
+        app.update();
+
+        assert_eq!(
+            overlay_root_count(&mut app),
+            1,
+            "exactly one ReplayOverlayRoot must spawn on Inactive → Playing",
+        );
+        assert_eq!(banner_text(&mut app), "Replay");
+    }
+
+    /// The progress-text entity reads `"Move {cursor} of {total}"` for a
+    /// well-formed `Playing` state.
+    #[test]
+    fn overlay_progress_text_reflects_cursor() {
+        let mut app = headless_app();
+        set_state(
+            &mut app,
+            ReplayPlaybackState::Playing {
+                replay: synthetic_replay(10),
+                cursor: 5,
+                secs_to_next: 0.5,
+            },
+        );
+        app.update();
+
+        assert_eq!(progress_text(&mut app), "Move 5 of 10");
+    }
+
+    /// Pressing the Stop button resets the state back to `Inactive` and
+    /// the next frame's `react_to_state_change` despawns the overlay.
+    /// Mirrors the synthetic `Interaction::Pressed` insertion pattern
+    /// used elsewhere in the engine for headless click tests.
+    #[test]
+    fn overlay_stop_button_click_clears_playback() {
+        let mut app = headless_app();
+        set_state(
+            &mut app,
+            ReplayPlaybackState::Playing {
+                replay: synthetic_replay(10),
+                cursor: 0,
+                secs_to_next: 0.5,
+            },
+        );
+        app.update();
+        assert_eq!(overlay_root_count(&mut app), 1);
+
+        let stop = stop_button_entity(&mut app);
+        app.world_mut()
+            .entity_mut(stop)
+            .insert(Interaction::Pressed);
+        // Tick once: the click handler runs late in the frame and resets
+        // the state to `Inactive`.
+        app.update();
+
+        // State must be back to Inactive.
+        let state = app.world().resource::<ReplayPlaybackState>();
+        assert!(
+            matches!(state, ReplayPlaybackState::Inactive),
+            "Stop click must reset ReplayPlaybackState to Inactive; got {state:?}",
+        );
+
+        // One more tick — `react_to_state_change` sees the resource
+        // change to Inactive and despawns the overlay.
+        app.update();
+        assert_eq!(
+            overlay_root_count(&mut app),
+            0,
+            "overlay must despawn the frame after state returns to Inactive",
+        );
+    }
+
+    /// Manually flipping the resource back to `Inactive` (e.g. via the
+    /// playback core's auto-clear after `Completed`) tears the overlay
+    /// down without any further input.
+    #[test]
+    fn overlay_despawns_when_playback_returns_to_inactive() {
+        let mut app = headless_app();
+        set_state(
+            &mut app,
+            ReplayPlaybackState::Playing {
+                replay: synthetic_replay(3),
+                cursor: 1,
+                secs_to_next: 0.5,
+            },
+        );
+        app.update();
+        assert_eq!(overlay_root_count(&mut app), 1);
+
+        set_state(&mut app, ReplayPlaybackState::Inactive);
+        app.update();
+
+        assert_eq!(
+            overlay_root_count(&mut app),
+            0,
+            "overlay must despawn on Playing → Inactive transition",
+        );
+    }
+
+    /// On `Playing → Completed` the banner label updates in place rather
+    /// than respawning. The overlay must still be present, and the label
+    /// must read "Replay complete".
+    #[test]
+    fn overlay_text_changes_on_completed() {
+        let mut app = headless_app();
+        set_state(
+            &mut app,
+            ReplayPlaybackState::Playing {
+                replay: synthetic_replay(7),
+                cursor: 7,
+                secs_to_next: 0.0,
+            },
+        );
+        app.update();
+        assert_eq!(banner_text(&mut app), "Replay");
+
+        set_state(&mut app, ReplayPlaybackState::Completed);
+        app.update();
+
+        assert_eq!(
+            overlay_root_count(&mut app),
+            1,
+            "overlay must remain spawned while in Completed state",
+        );
+        assert_eq!(
+            banner_text(&mut app),
+            "Replay complete",
+            "banner label must swap on Playing → Completed",
+        );
+    }
+}

solitaire_engine/src/replay_playback.rs

@@ -0,0 +1,682 @@
+//! In-engine replay playback core.
+//!
+//! When the player clicks "Watch replay" on the Stats overlay, the live
+//! game state is reset to the deal seeded from the replay's `seed` /
+//! `mode` / `draw_mode`, and the engine ticks through `replay.moves` at a
+//! steady cadence — firing the canonical [`MoveRequestEvent`] /
+//! [`DrawRequestEvent`] for each one. The existing animation pipeline
+//! plays back identically to a live game.
+//!
+//! ## Public surface
+//!
+//! - [`ReplayPlaybackState`] — single source of truth for whether
+//!   playback is live, how far through the move list we've ticked, and
+//!   how long until the next advance.
+//! - [`start_replay_playback`] — public entry point; the Stats
+//!   "Watch replay" button calls this. Resets the game to the recorded
+//!   deal and transitions the state machine to
+//!   [`ReplayPlaybackState::Playing`].
+//! - [`stop_replay_playback`] — interrupts playback at any time. Safe to
+//!   call when [`ReplayPlaybackState::Inactive`].
+//! - [`ReplayPlaybackPlugin`] — registers the resource and the tick /
+//!   linger systems.
+//!
+//! ## Coordination note
+//!
+//! This module is built in parallel with the Stats-side overlay. The
+//! resource shape, helper signatures, and plugin marker match the
+//! contract the overlay agent reads against — see also the docs on the
+//! enum variants.
+//!
+//! ## Recording is paused during playback
+//!
+//! Playback fires the same [`MoveRequestEvent`] / [`DrawRequestEvent`]
+//! the live engine handles. Without intervention, [`RecordingReplay`]
+//! would re-record those events and a replay would re-record itself
+//! indefinitely. To prevent that, [`record_replay_skip_during_playback`]
+//! snapshots the recording's length at the start of playback and
+//! truncates the buffer back to that length every frame. This keeps
+//! the recording contract opaque to `game_plugin` — no event-source
+//! flag is threaded through, no every-callsite gate is added.
+
+use bevy::prelude::*;
+use solitaire_data::{Replay, ReplayMove};
+
+use crate::events::{DrawRequestEvent, MoveRequestEvent, StateChangedEvent};
+use crate::game_plugin::{GameMutation, RecordingReplay};
+use crate::resources::GameStateResource;
+
+/// Per-move duration during playback. Tunable in Settings later;
+/// hardcoded for v1.
+pub const REPLAY_MOVE_INTERVAL_SECS: f32 = 0.45;
+
+/// How long the [`ReplayPlaybackState::Completed`] state lingers before
+/// the auto-clear system transitions it back to
+/// [`ReplayPlaybackState::Inactive`]. Gives the overlay UI time to
+/// display "Replay complete" before dismissing.
+pub const REPLAY_COMPLETION_LINGER_SECS: f32 = 5.0;
+
+/// Lifecycle state of an in-flight replay playback.
+///
+/// The default state is [`Inactive`](Self::Inactive) — no replay is
+/// running. The overlay (and any other consumer) reads this resource to
+/// decide whether the "Replay" banner should be visible and what
+/// progress to display.
+///
+/// Lifecycle:
+/// 1. Default state is [`Inactive`](Self::Inactive).
+/// 2. [`start_replay_playback`] transitions to
+///    [`Playing`](Self::Playing) and resets the live `GameState` to the
+///    replay's recorded deal.
+/// 3. The tick system [`tick_replay_playback`] advances `cursor` once
+///    per [`REPLAY_MOVE_INTERVAL_SECS`] and fires the canonical event
+///    for each [`ReplayMove`].
+/// 4. When `cursor == replay.moves.len()`, the state transitions to
+///    [`Completed`](Self::Completed). It lingers for
+///    [`REPLAY_COMPLETION_LINGER_SECS`] (driven by
+///    [`auto_clear_completed_replay`]) before returning to
+///    [`Inactive`](Self::Inactive).
+/// 5. [`stop_replay_playback`] interrupts at any time and forces the
+///    state back to [`Inactive`](Self::Inactive).
+#[derive(Resource, Debug, Default)]
+pub enum ReplayPlaybackState {
+    /// No replay is being played back. The overlay despawns itself when
+    /// the resource transitions back to this variant.
+    #[default]
+    Inactive,
+    /// A replay is currently being played back. The overlay reads
+    /// `replay.moves.len()` for the denominator of the progress
+    /// indicator and `cursor` for the numerator.
+    Playing {
+        /// The replay being played back. Owned so the state is the
+        /// only place playback metadata lives — no separate resource
+        /// needed.
+        replay: Replay,
+        /// Index of the next move to apply, in `[0, replay.moves.len()]`.
+        cursor: usize,
+        /// Seconds remaining until the next move is dispatched.
+        secs_to_next: f32,
+    },
+    /// The replay finished playing back. The overlay swaps the banner
+    /// label to "Replay complete" until [`auto_clear_completed_replay`]
+    /// transitions back to [`Inactive`](Self::Inactive) a few seconds
+    /// later.
+    Completed,
+}
+
+impl ReplayPlaybackState {
+    /// Returns `true` when a replay is currently being played back.
+    pub fn is_playing(&self) -> bool {
+        matches!(self, Self::Playing { .. })
+    }
+
+    /// Returns `true` when the replay has finished but the resource has
+    /// not yet been auto-cleared back to [`Self::Inactive`].
+    pub fn is_completed(&self) -> bool {
+        matches!(self, Self::Completed)
+    }
+
+    /// Returns `(cursor, total)` when a replay is in progress so the
+    /// overlay can render `"Move N of M"`. Returns `None` while
+    /// [`Inactive`](Self::Inactive) or [`Completed`](Self::Completed) —
+    /// the replay is consumed when transitioning out of `Playing`, so
+    /// the total is no longer available in `Completed`.
+    pub fn progress(&self) -> Option<(usize, usize)> {
+        match self {
+            Self::Playing { replay, cursor, .. } => Some((*cursor, replay.moves.len())),
+            Self::Inactive | Self::Completed => None,
+        }
+    }
+}
+
+/// Public entry point — call from the Stats "Watch replay" button
+/// handler.
+///
+/// Resets the live [`GameStateResource`] to a fresh deal seeded from
+/// `replay.seed` / `replay.draw_mode` / `replay.mode` (via
+/// [`Commands::insert_resource`]), then transitions the state machine
+/// to [`ReplayPlaybackState::Playing`] with `cursor: 0` and
+/// `secs_to_next: REPLAY_MOVE_INTERVAL_SECS`.
+///
+/// `commands` is used to overwrite [`GameStateResource`] in a deferred
+/// flush — equivalent to what `handle_new_game` does, minus the
+/// [`crate::events::NewGameRequestEvent`] round-trip and the
+/// abandon-current-game confirmation modal (which would block playback
+/// indefinitely). Using `Commands` rather than [`crate::events::NewGameRequestEvent`]
+/// also sidesteps the fact that `NewGameRequestEvent` has no
+/// `draw_mode_override` field — `handle_new_game` always reads
+/// `draw_mode` from `Settings`, which would silently coerce a Draw-1
+/// replay into a Draw-3 game (or vice versa) when the player's
+/// settings disagree with the recording.
+///
+/// Safe to call from any state — if a replay is already playing it is
+/// dropped and the new one starts immediately.
+pub fn start_replay_playback(
+    commands: &mut Commands,
+    state: &mut ResMut<ReplayPlaybackState>,
+    replay: Replay,
+) {
+    use solitaire_core::game_state::GameState;
+
+    let fresh = GameState::new_with_mode(replay.seed, replay.draw_mode.clone(), replay.mode);
+    commands.insert_resource(GameStateResource(fresh));
+
+    **state = ReplayPlaybackState::Playing {
+        replay,
+        cursor: 0,
+        secs_to_next: REPLAY_MOVE_INTERVAL_SECS,
+    };
+}
+
+/// Aborts an in-flight replay playback and resets
+/// [`ReplayPlaybackState`] back to [`ReplayPlaybackState::Inactive`].
+///
+/// Safe to call from any state — when already
+/// [`ReplayPlaybackState::Inactive`] it simply re-asserts inactivity.
+///
+/// The current [`GameStateResource`] is left as-is: the player sees the
+/// replay's most-recently-applied state until they start a fresh game
+/// manually. This avoids forcing an extra deal animation in their face
+/// the moment they cancel.
+///
+/// `commands` is currently unused but accepted to match the
+/// [`start_replay_playback`] signature — leaves room to hook in
+/// cleanup (e.g. despawning playback-only overlays) without a future
+/// API break.
+pub fn stop_replay_playback(
+    _commands: &mut Commands,
+    state: &mut ResMut<ReplayPlaybackState>,
+) {
+    **state = ReplayPlaybackState::Inactive;
+}
+
+/// Tick system. Runs every frame; only does work when
+/// [`ReplayPlaybackState::is_playing`].
+///
+/// Drains `secs_to_next` by `time.delta_secs()`. When the countdown
+/// expires, fires the canonical event for the move at `cursor`,
+/// increments `cursor`, and resets `secs_to_next`. When `cursor`
+/// reaches `replay.moves.len()`, transitions to
+/// [`ReplayPlaybackState::Completed`].
+///
+/// The advance loop is a `while`, not an `if`, so coarse time steps
+/// (e.g. test-driven 200 ms ticks against a 450 ms interval) still
+/// fire the right number of events — accumulated debt is paid off
+/// across as many advances as needed in the same frame. In normal
+/// gameplay frame deltas are well below `REPLAY_MOVE_INTERVAL_SECS`,
+/// so the loop runs at most once per frame.
+fn tick_replay_playback(
+    time: Res<Time>,
+    mut state: ResMut<ReplayPlaybackState>,
+    mut moves_writer: MessageWriter<MoveRequestEvent>,
+    mut draws_writer: MessageWriter<DrawRequestEvent>,
+) {
+    let dt = time.delta_secs();
+    let mut transition_to_completed = false;
+
+    if let ReplayPlaybackState::Playing {
+        replay,
+        cursor,
+        secs_to_next,
+    } = state.as_mut()
+    {
+        *secs_to_next -= dt;
+        while *secs_to_next <= 0.0 && *cursor < replay.moves.len() {
+            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;
+            *secs_to_next += REPLAY_MOVE_INTERVAL_SECS;
+        }
+
+        if *cursor >= replay.moves.len() {
+            transition_to_completed = true;
+        }
+    }
+
+    if transition_to_completed {
+        *state = ReplayPlaybackState::Completed;
+    }
+}
+
+/// Local timer for the [`ReplayPlaybackState::Completed`] linger.
+/// Resets to zero whenever the state transitions out of
+/// [`ReplayPlaybackState::Completed`].
+#[derive(Default)]
+struct CompletionLinger(f32);
+
+/// Auto-clear system. While [`ReplayPlaybackState::Completed`],
+/// accumulates time and transitions back to
+/// [`ReplayPlaybackState::Inactive`] once
+/// [`REPLAY_COMPLETION_LINGER_SECS`] has elapsed.
+fn auto_clear_completed_replay(
+    time: Res<Time>,
+    mut state: ResMut<ReplayPlaybackState>,
+    mut linger: Local<CompletionLinger>,
+) {
+    if state.is_completed() {
+        linger.0 += time.delta_secs();
+        if linger.0 >= REPLAY_COMPLETION_LINGER_SECS {
+            *state = ReplayPlaybackState::Inactive;
+            linger.0 = 0.0;
+        }
+    } else {
+        // Reset whenever we're not in Completed so the next completion
+        // measures from zero rather than accumulating across cycles.
+        linger.0 = 0.0;
+    }
+}
+
+/// Local cache of the recording buffer's length at the start of
+/// playback. Lets us roll back any growth during playback without
+/// touching `game_plugin`'s recording call sites.
+#[derive(Default)]
+struct RecordingSnapshot {
+    /// `Some(len)` while playback is active. The recording is
+    /// truncated back to this length every frame so playback-driven
+    /// events leak no entries into the recorded move list. `None`
+    /// when not playing — recording behaves normally.
+    snapshot_len: Option<usize>,
+}
+
+/// Recording-pause system. While [`ReplayPlaybackState::is_playing`],
+/// snapshots the recording's length on entry and truncates the
+/// recording back to that length every frame. This keeps the live
+/// [`RecordingReplay`] opaque to `game_plugin`'s `handle_move` /
+/// `handle_draw` — those still push unconditionally; we just wipe the
+/// playback-driven entries before any other system can read them.
+///
+/// Implemented this way because [`RecordingReplay`] is mutated inside
+/// the [`GameMutation`] system set (the schedule set that owns
+/// `handle_move` / `handle_draw`). We schedule this system
+/// `.after(GameMutation)` so the truncation runs each frame *after*
+/// the unconditional push, removing the same entry the playback tick
+/// caused.
+fn record_replay_skip_during_playback(
+    state: Res<ReplayPlaybackState>,
+    mut recording: ResMut<RecordingReplay>,
+    mut snap: Local<RecordingSnapshot>,
+) {
+    // Treat `Playing` and `Completed` identically for the purpose of
+    // recording suppression. The tick system's final advance fires
+    // its event in the same frame it transitions to `Completed`; the
+    // event is then consumed by `handle_move` / `handle_draw` either
+    // this frame (race-dependent on system order) or the next. By
+    // suppressing recording growth across both states, we close that
+    // window cleanly: the snapshot survives until the resource is
+    // back to `Inactive` (auto-cleared after
+    // `REPLAY_COMPLETION_LINGER_SECS`).
+    if state.is_playing() || state.is_completed() {
+        let baseline = match snap.snapshot_len {
+            Some(n) => n,
+            None => {
+                let n = recording.moves.len();
+                snap.snapshot_len = Some(n);
+                n
+            }
+        };
+        if recording.moves.len() > baseline {
+            recording.moves.truncate(baseline);
+        }
+    } else {
+        // Drop the snapshot when neither playing nor completed so
+        // the next playback cycle re-anchors to whatever the
+        // recording is at that point.
+        snap.snapshot_len = None;
+    }
+}
+
+/// On-completion side effect: fire a single [`StateChangedEvent`] when
+/// playback transitions from `Playing` to `Completed` so any UI that
+/// listens for state mutations refreshes one final time. Cheap and
+/// idempotent — `StateChangedEvent` is a one-shot signal.
+fn fire_state_changed_on_completion(
+    state: Res<ReplayPlaybackState>,
+    mut last_was_completed: Local<bool>,
+    mut writer: MessageWriter<StateChangedEvent>,
+) {
+    let now_completed = state.is_completed();
+    if now_completed && !*last_was_completed {
+        writer.write(StateChangedEvent);
+    }
+    *last_was_completed = now_completed;
+}
+
+/// Bevy plugin that initialises [`ReplayPlaybackState`] and drives
+/// playback ticks, completion linger, and the recording-pause guard.
+///
+/// Register this in the main app alongside [`crate::game_plugin::GamePlugin`].
+/// Tests can install it under [`MinimalPlugins`] to exercise the public
+/// API without spinning up the full client.
+pub struct ReplayPlaybackPlugin;
+
+impl Plugin for ReplayPlaybackPlugin {
+    fn build(&self, app: &mut App) {
+        app.init_resource::<ReplayPlaybackState>()
+            .add_systems(
+                Update,
+                (
+                    tick_replay_playback,
+                    auto_clear_completed_replay,
+                    fire_state_changed_on_completion,
+                )
+                    .chain(),
+            )
+            .add_systems(
+                Update,
+                record_replay_skip_during_playback.after(GameMutation),
+            );
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Tests
+// ---------------------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::game_plugin::GamePlugin;
+    use bevy::time::TimeUpdateStrategy;
+    use chrono::NaiveDate;
+    use solitaire_core::game_state::{DrawMode, GameMode};
+    use solitaire_core::pile::PileType;
+    use std::time::Duration;
+
+    /// Builds a headless `App` with `MinimalPlugins`, `GamePlugin`, and
+    /// `ReplayPlaybackPlugin`. `GamePlugin` brings the canonical
+    /// `MoveRequestEvent` / `DrawRequestEvent` registrations along with
+    /// `RecordingReplay` so the recording-pause test can read it.
+    fn headless_app() -> App {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins)
+            .add_plugins(GamePlugin::headless())
+            .add_plugins(ReplayPlaybackPlugin);
+        // Disable game-state persistence so tests don't touch the
+        // real ~/.local/share/solitaire_quest/game_state.json.
+        app.insert_resource(crate::game_plugin::GameStatePath(None));
+        app.insert_resource(crate::game_plugin::ReplayPath(None));
+        // Tick once so any startup systems flush before the first
+        // assertion.
+        app.update();
+        app
+    }
+
+    /// `Time<Virtual>` clamps each tick to `max_delta` (default 250 ms),
+    /// so we drive 200 ms steps and call `update` enough times to pass
+    /// the requested duration.
+    fn advance_by(app: &mut App, total_secs: f32) {
+        app.insert_resource(TimeUpdateStrategy::ManualDuration(
+            Duration::from_secs_f32(0.2),
+        ));
+        let ticks = (total_secs / 0.2).ceil() as usize + 1;
+        for _ in 0..ticks {
+            app.update();
+        }
+    }
+
+    /// A 3-move replay covering both `Move` and `StockClick` variants.
+    /// Seed 12345 is arbitrary — the test asserts on event counts and
+    /// move shapes, not on board positions.
+    fn sample_replay_three_moves() -> Replay {
+        Replay::new(
+            12345,
+            DrawMode::DrawOne,
+            GameMode::Classic,
+            60,
+            500,
+            NaiveDate::from_ymd_opt(2026, 5, 5).expect("valid date"),
+            vec![
+                ReplayMove::StockClick,
+                ReplayMove::Move {
+                    from: PileType::Waste,
+                    to: PileType::Tableau(3),
+                    count: 1,
+                },
+                ReplayMove::StockClick,
+            ],
+        )
+    }
+
+    /// Scoped helper to invoke `start_replay_playback` from within the
+    /// app's `World` (the public API takes `Commands`, which only
+    /// exists inside systems). We use a one-shot system to obtain the
+    /// `Commands`.
+    fn start_playback(app: &mut App, replay: Replay) {
+        #[derive(Resource)]
+        struct ReplayInbox(Option<Replay>);
+        app.insert_resource(ReplayInbox(Some(replay)));
+
+        fn run(
+            mut commands: Commands,
+            mut state: ResMut<ReplayPlaybackState>,
+            mut inbox: ResMut<ReplayInbox>,
+        ) {
+            if let Some(replay) = inbox.0.take() {
+                start_replay_playback(&mut commands, &mut state, replay);
+            }
+        }
+        let id = app.world_mut().register_system(run);
+        app.world_mut()
+            .run_system(id)
+            .expect("one-shot start_playback");
+    }
+
+    fn stop_playback(app: &mut App) {
+        fn run(mut commands: Commands, mut state: ResMut<ReplayPlaybackState>) {
+            stop_replay_playback(&mut commands, &mut state);
+        }
+        let id = app.world_mut().register_system(run);
+        app.world_mut()
+            .run_system(id)
+            .expect("one-shot stop_playback");
+    }
+
+    /// Fresh state must be `Inactive`. After `start_replay_playback`
+    /// the state must be `Playing { cursor: 0, .. }` carrying the
+    /// supplied replay.
+    #[test]
+    fn start_replay_playback_transitions_inactive_to_playing() {
+        let mut app = headless_app();
+        assert!(matches!(
+            *app.world().resource::<ReplayPlaybackState>(),
+            ReplayPlaybackState::Inactive
+        ));
+
+        let replay = sample_replay_three_moves();
+        start_playback(&mut app, replay.clone());
+        // Apply the deferred Commands flush.
+        app.update();
+
+        let state = app.world().resource::<ReplayPlaybackState>();
+        match state {
+            ReplayPlaybackState::Playing {
+                cursor,
+                replay: r,
+                ..
+            } => {
+                assert_eq!(*cursor, 0);
+                assert_eq!(r.seed, replay.seed);
+                assert_eq!(r.moves.len(), 3);
+            }
+            other => panic!("expected Playing, got {other:?}"),
+        }
+        assert_eq!(state.progress(), Some((0, 3)));
+    }
+
+    /// One full interval (plus a small margin to clear the boundary)
+    /// must advance the cursor by at least one.
+    #[test]
+    fn tick_advances_cursor_after_interval() {
+        let mut app = headless_app();
+        start_playback(&mut app, sample_replay_three_moves());
+        app.update();
+
+        // Drive virtual time forward by one interval.
+        advance_by(&mut app, REPLAY_MOVE_INTERVAL_SECS + 0.05);
+
+        let state = app.world().resource::<ReplayPlaybackState>();
+        match state {
+            ReplayPlaybackState::Playing { cursor, .. } => {
+                assert!(
+                    *cursor >= 1,
+                    "expected cursor advanced past one move, got {cursor}",
+                );
+            }
+            other => panic!("expected Playing, got {other:?}"),
+        }
+    }
+
+    /// Driving past `n * REPLAY_MOVE_INTERVAL_SECS` must produce
+    /// `n` events that match the recorded move kinds. We register a
+    /// pair of accumulator systems that drain `MoveRequestEvent` /
+    /// `DrawRequestEvent` into resources every frame — using a
+    /// detached cursor across many `app.update()` calls is unreliable
+    /// because Bevy's `Messages` double-buffer drops events older
+    /// than two frames.
+    #[test]
+    fn tick_fires_canonical_event_for_each_move() {
+        #[derive(Resource, Default)]
+        struct CapturedMoves(Vec<MoveRequestEvent>);
+        #[derive(Resource, Default)]
+        struct CapturedDraws(usize);
+
+        fn collect_moves(
+            mut events: MessageReader<MoveRequestEvent>,
+            mut sink: ResMut<CapturedMoves>,
+        ) {
+            for ev in events.read() {
+                sink.0.push(ev.clone());
+            }
+        }
+        fn collect_draws(
+            mut events: MessageReader<DrawRequestEvent>,
+            mut sink: ResMut<CapturedDraws>,
+        ) {
+            for _ in events.read() {
+                sink.0 += 1;
+            }
+        }
+
+        let mut app = headless_app();
+        app.init_resource::<CapturedMoves>()
+            .init_resource::<CapturedDraws>()
+            .add_systems(Update, (collect_moves, collect_draws));
+
+        start_playback(&mut app, sample_replay_three_moves());
+        app.update();
+
+        // Drive through 3 intervals. Add a small margin to ensure the
+        // last firing isn't sitting exactly on the boundary.
+        advance_by(&mut app, REPLAY_MOVE_INTERVAL_SECS * 3.0 + 0.1);
+
+        let captured_moves = app.world().resource::<CapturedMoves>();
+        let captured_draws = app.world().resource::<CapturedDraws>();
+
+        // Sample replay: StockClick, Move { Waste -> Tableau(3), 1 }, StockClick.
+        assert_eq!(
+            captured_draws.0, 2,
+            "expected 2 DrawRequestEvent (two StockClicks)",
+        );
+        assert_eq!(
+            captured_moves.0.len(),
+            1,
+            "expected 1 MoveRequestEvent (the single Move variant)",
+        );
+        let m = &captured_moves.0[0];
+        assert!(matches!(m.from, PileType::Waste));
+        assert!(matches!(m.to, PileType::Tableau(3)));
+        assert_eq!(m.count, 1);
+    }
+
+    /// Driving past one interval on a single-move replay must
+    /// transition to `Completed`.
+    #[test]
+    fn playback_completes_when_cursor_reaches_end() {
+        let mut app = headless_app();
+        let one_move = Replay::new(
+            42,
+            DrawMode::DrawOne,
+            GameMode::Classic,
+            10,
+            100,
+            NaiveDate::from_ymd_opt(2026, 5, 5).expect("valid date"),
+            vec![ReplayMove::StockClick],
+        );
+        start_playback(&mut app, one_move);
+        app.update();
+
+        advance_by(&mut app, REPLAY_MOVE_INTERVAL_SECS + 0.1);
+
+        let state = app.world().resource::<ReplayPlaybackState>();
+        assert!(
+            state.is_completed(),
+            "expected Completed after consuming the only move, got {state:?}",
+        );
+    }
+
+    /// `stop_replay_playback` must force the state back to `Inactive`
+    /// even mid-playback.
+    #[test]
+    fn stop_replay_playback_returns_to_inactive() {
+        let mut app = headless_app();
+        start_playback(&mut app, sample_replay_three_moves());
+        app.update();
+        // Tick once so the state is well and truly `Playing`.
+        advance_by(&mut app, 0.1);
+        assert!(app.world().resource::<ReplayPlaybackState>().is_playing());
+
+        stop_playback(&mut app);
+        app.update();
+
+        assert!(matches!(
+            *app.world().resource::<ReplayPlaybackState>(),
+            ReplayPlaybackState::Inactive
+        ));
+    }
+
+    /// Recording must remain frozen during playback. Pre-populate the
+    /// recording with one entry, start playback, and assert the
+    /// recording's move list is unchanged after several ticks.
+    #[test]
+    fn recording_paused_during_playback() {
+        let mut app = headless_app();
+        // Pre-populate the recording with one entry that should
+        // survive playback unchanged. Mirrors the situation where the
+        // player partway through a game opens stats and clicks Watch
+        // Replay — their in-flight recording must not get clobbered.
+        {
+            let mut rec = app.world_mut().resource_mut::<RecordingReplay>();
+            rec.moves.push(ReplayMove::StockClick);
+        }
+        start_playback(&mut app, sample_replay_three_moves());
+        app.update();
+
+        let baseline_len = app.world().resource::<RecordingReplay>().moves.len();
+        assert_eq!(
+            baseline_len, 1,
+            "preconditions: recording starts with one entry",
+        );
+
+        // Drive playback through every move in the replay. Each move
+        // would normally append to `RecordingReplay`; the pause
+        // system must clamp the recording back to `baseline_len` on
+        // every frame.
+        advance_by(&mut app, REPLAY_MOVE_INTERVAL_SECS * 4.0 + 0.1);
+
+        let after_len = app.world().resource::<RecordingReplay>().moves.len();
+        assert_eq!(
+            after_len, baseline_len,
+            "recording must not grow while playback is active",
+        );
+    }
+}

solitaire_engine/src/settings_plugin.rs

@@ -18,13 +18,14 @@ use bevy::window::{WindowMoved, WindowResized};
 use solitaire_core::game_state::DrawMode;
 use solitaire_data::{
     load_settings_from, save_settings_to, settings_file_path, settings::Theme, AnimSpeed, Settings,
-    WindowGeometry, TOOLTIP_DELAY_STEP_SECS,
+    WindowGeometry, TIME_BONUS_MULTIPLIER_STEP, TOOLTIP_DELAY_STEP_SECS,
 };
 
 use crate::events::{ManualSyncRequestEvent, ToggleSettingsRequestEvent};
 use crate::font_plugin::FontResource;
 use crate::progress_plugin::ProgressResource;
 use crate::resources::{SettingsScrollPos, SyncStatus, SyncStatusResource};
+use crate::theme::{ThemeThumbnailCache, ThemeThumbnailPair};
 use crate::ui_focus::{FocusGroup, FocusRow, Focusable, FocusedButton};
 use crate::ui_modal::{
     spawn_modal, spawn_modal_actions, spawn_modal_button, spawn_modal_header, ButtonVariant,
@@ -32,8 +33,9 @@ use crate::ui_modal::{
 };
 use crate::ui_tooltip::Tooltip;
 use crate::ui_theme::{
-    BG_BASE, BG_ELEVATED_HI, BORDER_SUBTLE, RADIUS_SM, SPACE_2, STATE_SUCCESS, TEXT_PRIMARY,
+    BG_BASE, BG_ELEVATED, BG_ELEVATED_HI, BORDER_SUBTLE, RADIUS_SM, SPACE_2, STATE_SUCCESS,
-    TEXT_SECONDARY, TYPE_BODY, TYPE_BODY_LG, TYPE_CAPTION, VAL_SPACE_2, VAL_SPACE_3, Z_MODAL_PANEL,
+    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.
@@ -126,6 +128,15 @@ struct ColorBlindText;
 #[derive(Component, Debug)]
 struct TooltipDelayText;
 
+/// Marks the `Text` node showing the live time-bonus-multiplier value.
+#[derive(Component, Debug)]
+struct TimeBonusMultiplierText;
+
+/// Marks the `Text` node showing the current "Winnable deals only"
+/// state ("ON" / "OFF") in the Gameplay section.
+#[derive(Component, Debug)]
+struct WinnableDealsOnlyText;
+
 /// Marks the scrollable inner card so the mouse-wheel system can target it.
 #[derive(Component, Debug)]
 struct SettingsPanelScrollable;
@@ -134,6 +145,23 @@ struct SettingsPanelScrollable;
 #[derive(Component, Debug)]
 struct SettingsScrollNode;
 
+/// Snapshot row used by [`spawn_settings_panel`] to render the card-art
+/// theme picker. Carries the `ThemeRegistry` entry's display fields plus
+/// the (optional) thumbnail pair from [`ThemeThumbnailCache`]. A `None`
+/// thumbnail means the picker should render a placeholder swatch — used
+/// when the cache hasn't generated handles yet, or when a user theme
+/// is missing one of the required preview SVGs.
+#[derive(Debug, Clone)]
+struct ThemePickerEntry {
+    /// Stable theme id (matches `ThemeMeta::id`).
+    id: String,
+    /// Player-facing label.
+    display_name: String,
+    /// Pre-generated picker preview pair, when ready. `None` collapses
+    /// the chip to its plain-text fallback.
+    thumbnails: Option<ThemeThumbnailPair>,
+}
+
 /// Tags interactive buttons inside the Settings panel.
 #[derive(Component, Debug)]
 enum SettingsButton {
@@ -147,8 +175,17 @@ enum SettingsButton {
     TooltipDelayDown,
     /// Increment the tooltip-hover dwell delay by one step.
     TooltipDelayUp,
+    /// Decrement the cosmetic time-bonus multiplier by one step.
+    TimeBonusDown,
+    /// Increment the cosmetic time-bonus multiplier by one step.
+    TimeBonusUp,
     ToggleTheme,
     ToggleColorBlind,
+    /// Toggle the [`Settings::winnable_deals_only`] flag. When on, new
+    /// random Classic-mode deals are filtered through
+    /// [`solitaire_core::solver::try_solve`] until one is provably
+    /// winnable (or the retry cap is hit). Off by default.
+    ToggleWinnableDealsOnly,
     SyncNow,
     Done,
     /// Select a specific card-back by index from the picker row.
@@ -176,9 +213,12 @@ impl SettingsButton {
             SettingsButton::MusicUp => 21,
             // Gameplay section
             SettingsButton::ToggleDrawMode => 30,
+            SettingsButton::ToggleWinnableDealsOnly => 35,
             SettingsButton::CycleAnimSpeed => 40,
             SettingsButton::TooltipDelayDown => 45,
             SettingsButton::TooltipDelayUp => 46,
+            SettingsButton::TimeBonusDown => 47,
+            SettingsButton::TimeBonusUp => 48,
             // Cosmetic section
             SettingsButton::ToggleTheme => 50,
             SettingsButton::ToggleColorBlind => 60,
@@ -269,6 +309,8 @@ impl Plugin for SettingsPlugin {
                     update_anim_speed_text,
                     update_color_blind_text,
                     update_tooltip_delay_text,
+                    update_time_bonus_multiplier_text,
+                    update_winnable_deals_only_text,
                     attach_focusable_to_settings_buttons,
                     scroll_focus_into_view,
                 ),
@@ -370,6 +412,7 @@ fn sync_settings_panel_visibility(
     progress: Option<Res<ProgressResource>>,
     font_res: Option<Res<FontResource>>,
     theme_registry: Option<Res<crate::theme::ThemeRegistry>>,
+    theme_thumbs: Option<Res<ThemeThumbnailCache>>,
     card_images: Option<Res<crate::card_plugin::CardImageSet>>,
 ) {
     if !screen.is_changed() {
@@ -385,15 +428,27 @@ fn sync_settings_panel_visibility(
             let unlocked_bgs = progress
                 .as_ref()
                 .map_or(&[0][..], |p| p.0.unlocked_backgrounds.as_slice());
-            // Snapshot themes by id+display_name so spawn_settings_panel
+            // Snapshot themes by id, display_name and (optional)
-            // doesn't have to know about the registry shape. Empty when
+            // thumbnail pair so spawn_settings_panel doesn't have to
+            // know about the registry / cache shapes. Empty when
             // ThemeRegistryPlugin isn't installed (tests under
             // MinimalPlugins) — the picker row simply won't render.
-            let themes: Vec<(String, String)> = theme_registry
+            // Missing thumbnails (cache not ready, or partial user
+            // theme) leave `thumbnails: None` so the chip renders its
+            // plain-text fallback instead of a broken sprite.
+            let themes: Vec<ThemePickerEntry> = theme_registry
                 .as_deref()
                 .map(|r| {
                     r.iter()
-                        .map(|e| (e.id.clone(), e.display_name.clone()))
+                        .map(|e| ThemePickerEntry {
+                            id: e.id.clone(),
+                            display_name: e.display_name.clone(),
+                            thumbnails: theme_thumbs
+                                .as_deref()
+                                .and_then(|c| c.get(&e.id))
+                                .filter(|p| p.is_fully_populated())
+                                .cloned(),
+                        })
                         .collect()
                 })
                 .unwrap_or_default();
@@ -506,6 +561,21 @@ fn update_color_blind_text(
     }
 }
 
+/// Refreshes the live "Winnable deals only" toggle value in the
+/// Gameplay section whenever `SettingsResource` changes (button click,
+/// hand-edited `settings.json` reload, etc.).
+fn update_winnable_deals_only_text(
+    settings: Res<SettingsResource>,
+    mut text_nodes: Query<&mut Text, With<WinnableDealsOnlyText>>,
+) {
+    if !settings.is_changed() {
+        return;
+    }
+    for mut text in &mut text_nodes {
+        **text = winnable_deals_only_label(settings.0.winnable_deals_only);
+    }
+}
+
 /// Refreshes the live tooltip-delay value in the Gameplay section
 /// whenever `SettingsResource` changes (slider buttons, hand-edited
 /// settings.json reload, etc.).
@@ -521,6 +591,20 @@ fn update_tooltip_delay_text(
     }
 }
 
+/// Refreshes the live time-bonus-multiplier value in the Gameplay
+/// section whenever `SettingsResource` changes.
+fn update_time_bonus_multiplier_text(
+    settings: Res<SettingsResource>,
+    mut text_nodes: Query<&mut Text, With<TimeBonusMultiplierText>>,
+) {
+    if !settings.is_changed() {
+        return;
+    }
+    for mut text in &mut text_nodes {
+        **text = time_bonus_label(settings.0.time_bonus_multiplier);
+    }
+}
+
 fn card_back_label(idx: usize) -> String {
     if idx == 0 {
         "Default".to_string()
@@ -662,6 +746,25 @@ fn handle_settings_buttons(
                     changed.write(SettingsChangedEvent(settings.0.clone()));
                 }
             }
+            SettingsButton::TimeBonusDown => {
+                let before = settings.0.time_bonus_multiplier;
+                let after = settings.0.adjust_time_bonus_multiplier(-TIME_BONUS_MULTIPLIER_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                    // The Text node is refreshed by
+                    // `update_time_bonus_multiplier_text` on the next
+                    // frame via `settings.is_changed()`.
+                }
+            }
+            SettingsButton::TimeBonusUp => {
+                let before = settings.0.time_bonus_multiplier;
+                let after = settings.0.adjust_time_bonus_multiplier(TIME_BONUS_MULTIPLIER_STEP);
+                if (before - after).abs() > f32::EPSILON {
+                    persist(&path, &settings.0);
+                    changed.write(SettingsChangedEvent(settings.0.clone()));
+                }
+            }
             SettingsButton::ToggleTheme => {
                 settings.0.theme = match settings.0.theme {
                     Theme::Green => Theme::Blue,
@@ -682,6 +785,13 @@ fn handle_settings_buttons(
                     **t = color_blind_label(settings.0.color_blind_mode);
                 }
             }
+            SettingsButton::ToggleWinnableDealsOnly => {
+                settings.0.winnable_deals_only = !settings.0.winnable_deals_only;
+                persist(&path, &settings.0);
+                changed.write(SettingsChangedEvent(settings.0.clone()));
+                // The Text node is refreshed by `update_winnable_deals_only_text`
+                // on the next frame via `settings.is_changed()`.
+            }
             SettingsButton::SelectCardBack(idx) => {
                 settings.0.selected_card_back = *idx;
                 persist(&path, &settings.0);
@@ -736,6 +846,13 @@ fn color_blind_label(enabled: bool) -> String {
     if enabled { "ON".into() } else { "OFF".into() }
 }
 
+/// Display string for the "Winnable deals only" toggle. Mirrors
+/// [`color_blind_label`] — "ON" / "OFF" — so the layout is uniform
+/// with the rest of the Gameplay-section toggles.
+fn winnable_deals_only_label(enabled: bool) -> String {
+    if enabled { "ON".into() } else { "OFF".into() }
+}
+
 /// Formats the tooltip-hover delay for display in the Settings panel.
 /// `0.0` reads as `"Instant"` so the zero-delay case has a name; any
 /// other value prints as `"{n:.1} s"` (e.g. `"0.5 s"`, `"1.2 s"`).
@@ -747,6 +864,18 @@ fn tooltip_delay_label(secs: f32) -> String {
     }
 }
 
+/// Formats the cosmetic time-bonus multiplier for display in the
+/// Settings panel. `0.0` reads as `"Off"` so the player understands the
+/// time-bonus row will be hidden; any other value prints as
+/// `"{n:.1}×"` (e.g. `"1.0×"`, `"1.5×"`).
+fn time_bonus_label(value: f32) -> String {
+    if value <= 0.0 {
+        "Off".into()
+    } else {
+        format!("{value:.1}×")
+    }
+}
+
 /// Auto-attaches [`Focusable`] to every bespoke Settings button — icon
 /// buttons (volume +/−, toggle, cycle), swatch buttons (card-back,
 /// background pickers), and the "Sync Now" button. The "Done" button is
@@ -1010,7 +1139,7 @@ fn spawn_settings_panel(
     sync_status: &str,
     unlocked_card_backs: &[usize],
     unlocked_backgrounds: &[usize],
-    themes: &[(String, String)],
+    themes: &[ThemePickerEntry],
     scroll_offset: f32,
     font_res: Option<&FontResource>,
     theme_overrides_back: bool,
@@ -1070,6 +1199,16 @@ fn spawn_settings_panel(
                 "Switch between Draw 1 and Draw 3. Takes effect next deal.",
                 font_res,
             );
+            toggle_row(
+                body,
+                "Winnable deals only",
+                WinnableDealsOnlyText,
+                winnable_deals_only_label(settings.winnable_deals_only),
+                SettingsButton::ToggleWinnableDealsOnly,
+                "When on, fresh Classic deals are filtered through a solver \
+                 (may take a moment when on).",
+                font_res,
+            );
             toggle_row(
                 body,
                 "Anim Speed",
@@ -1084,6 +1223,11 @@ fn spawn_settings_panel(
                 settings.tooltip_delay_secs,
                 font_res,
             );
+            time_bonus_multiplier_row(
+                body,
+                settings.time_bonus_multiplier,
+                font_res,
+            );
 
             // --- Cosmetic ---
             section_label(body, "Cosmetic", font_res);
@@ -1268,6 +1412,56 @@ fn tooltip_delay_row(
         });
 }
 
+/// `Time bonus  1.0×  [−]  [+]` — slider row for the cosmetic
+/// `Settings::time_bonus_multiplier`. Mirrors [`tooltip_delay_row`]
+/// (label, current value, decrement, increment) but formats the value
+/// via [`time_bonus_label`] so `0.0` reads as `"Off"` and other values
+/// as `"{n:.1}×"`. The multiplier is **cosmetic** — adjusting it
+/// changes only the win-modal score breakdown, not the canonical
+/// scores recorded in stats / achievements / leaderboards.
+fn time_bonus_multiplier_row(
+    parent: &mut ChildSpawnerCommands,
+    value: f32,
+    font_res: Option<&FontResource>,
+) {
+    let label_font = label_text_font(font_res);
+    let value_font = value_text_font(font_res);
+    parent
+        .spawn(Node {
+            flex_direction: FlexDirection::Row,
+            align_items: AlignItems::Center,
+            column_gap: VAL_SPACE_2,
+            ..default()
+        })
+        .with_children(|row| {
+            row.spawn((
+                Text::new("Time bonus".to_string()),
+                label_font,
+                TextColor(TEXT_SECONDARY),
+            ));
+            row.spawn((
+                TimeBonusMultiplierText,
+                Text::new(time_bonus_label(value)),
+                value_font,
+                TextColor(TEXT_PRIMARY),
+            ));
+            icon_button(
+                row,
+                "−",
+                SettingsButton::TimeBonusDown,
+                "Shrink the time-bonus shown in the win modal. Cosmetic only.",
+                font_res,
+            );
+            icon_button(
+                row,
+                "+",
+                SettingsButton::TimeBonusUp,
+                "Boost the time-bonus shown in the win modal. Cosmetic only.",
+                font_res,
+            );
+        });
+}
+
 /// `Label  Value  [⇄]` — used for cycle/toggle rows (draw mode, theme,
 /// anim speed, colour-blind).
 ///
@@ -1384,6 +1578,13 @@ fn picker_row(
 #[derive(Component, Debug)]
 pub(crate) struct CardBackPickerOverriddenByTheme;
 
+/// Marker placed on every preview-thumbnail [`ImageNode`] inside a
+/// theme picker chip. Lets tests assert that a chip's children include
+/// the rasterised preview pair, and lets a future system update or
+/// hot-swap thumbnails without scanning the whole UI tree.
+#[derive(Component, Debug)]
+pub(crate) struct ThemeThumbnailMarker;
+
 /// Renders the "Card Back" row in its overridden-by-theme state: a
 /// labelled caption explaining why the swatches are hidden, with no
 /// interactive children. This is what the player sees when the active
@@ -1426,14 +1627,25 @@ fn picker_row_overridden_by_theme(
         });
 }
 
+/// Logical width (px) of one preview thumbnail inside a picker chip.
+/// Mirrors [`crate::theme::THEME_THUMBNAIL_WIDTH_PX`] but at the UI
+/// scale used by Bevy's flex layout. The rasterised image itself is
+/// 100×140 px; the chip displays it at the same logical size so
+/// scaling artifacts stay minimal.
+const THUMBNAIL_LOGICAL_WIDTH_PX: f32 = 50.0;
+/// Logical height counterpart to [`THUMBNAIL_LOGICAL_WIDTH_PX`] —
+/// preserves the 2:3 card aspect.
+const THUMBNAIL_LOGICAL_HEIGHT_PX: f32 = 70.0;
+
 /// Picker row for card-art themes. Distinct from [`picker_row`]
 /// because themes are identified by `String` ids (matching
 /// `ThemeMeta::id`) instead of dense indices, and each chip carries
-/// the theme's display name rather than a numeric label.
+/// the theme's display name plus a small Ace + back preview pair
+/// (when available in [`ThemeThumbnailCache`]).
 fn theme_picker_row(
     parent: &mut ChildSpawnerCommands,
     label: &str,
-    themes: &[(String, String)],
+    themes: &[ThemePickerEntry],
     selected_id: &str,
     tooltip: &'static str,
     font_res: Option<&FontResource>,
@@ -1461,19 +1673,25 @@ fn theme_picker_row(
                 label_font,
                 TextColor(TEXT_SECONDARY),
             ));
-            for (id, display_name) in themes {
+            for entry in themes {
-                let is_selected = id == selected_id;
+                let is_selected = entry.id == selected_id;
                 let bg = if is_selected { STATE_SUCCESS } else { BG_ELEVATED_HI };
                 row.spawn((
-                    SettingsButton::SelectTheme(id.clone()),
+                    SettingsButton::SelectTheme(entry.id.clone()),
                     Button,
                     Tooltip::new(tooltip),
                     Node {
+                        // Chips with thumbnails stack the preview pair
+                        // above the label so a glance reveals the
+                        // theme's art without hovering for the
+                        // tooltip.
+                        flex_direction: FlexDirection::Column,
                         // Theme names are wider than numeric chips —
                         // pad horizontally instead of using a fixed
                         // square swatch.
-                        padding: UiRect::axes(VAL_SPACE_3, VAL_SPACE_2),
+                        padding: UiRect::axes(VAL_SPACE_2, VAL_SPACE_2),
                         min_height: Val::Px(SWATCH_PX),
+                        row_gap: VAL_SPACE_2,
                         justify_content: JustifyContent::Center,
                         align_items: AlignItems::Center,
                         border: UiRect::all(Val::Px(1.0)),
@@ -1484,9 +1702,10 @@ fn theme_picker_row(
                     BorderColor::all(BORDER_SUBTLE),
                 ))
                 .with_children(|b| {
+                    spawn_thumbnail_pair(b, entry.thumbnails.as_ref());
                     let text_color = if is_selected { BG_BASE } else { TEXT_PRIMARY };
                     b.spawn((
-                        Text::new(display_name.clone()),
+                        Text::new(entry.display_name.clone()),
                         chip_font.clone(),
                         TextColor(text_color),
                     ));
@@ -1495,6 +1714,70 @@ fn theme_picker_row(
         });
 }
 
+/// Spawns the Ace + back preview pair for a theme picker chip.
+///
+/// When `thumbnails` is `Some(_)` and both handles are non-default,
+/// renders two `ImageNode` siblings (Ace on the left, back on the
+/// right). When the thumbnails are missing or only partially loaded,
+/// renders two muted `BG_ELEVATED` placeholder rectangles at the same
+/// logical size — keeping the chip's overall footprint stable so the
+/// picker row layout doesn't reflow as the cache fills in.
+fn spawn_thumbnail_pair(
+    parent: &mut ChildSpawnerCommands,
+    thumbnails: Option<&ThemeThumbnailPair>,
+) {
+    parent
+        .spawn(Node {
+            flex_direction: FlexDirection::Row,
+            column_gap: VAL_SPACE_2,
+            align_items: AlignItems::Center,
+            ..default()
+        })
+        .with_children(|pair| {
+            match thumbnails {
+                Some(t) if t.is_fully_populated() => {
+                    spawn_thumbnail_image(pair, t.ace.clone());
+                    spawn_thumbnail_image(pair, t.back.clone());
+                }
+                _ => {
+                    spawn_thumbnail_placeholder(pair);
+                    spawn_thumbnail_placeholder(pair);
+                }
+            }
+        });
+}
+
+/// Spawns one `ImageNode` thumbnail at the canonical preview size.
+/// Tagged with [`ThemeThumbnailMarker`] so tests can scan a chip's
+/// children for the rendered preview without crawling the whole UI.
+fn spawn_thumbnail_image(parent: &mut ChildSpawnerCommands, image: Handle<Image>) {
+    parent.spawn((
+        ThemeThumbnailMarker,
+        ImageNode::new(image),
+        Node {
+            width: Val::Px(THUMBNAIL_LOGICAL_WIDTH_PX),
+            height: Val::Px(THUMBNAIL_LOGICAL_HEIGHT_PX),
+            ..default()
+        },
+    ));
+}
+
+/// Spawns a muted placeholder rectangle for the case where the cache
+/// has not yet generated thumbnails for a theme — or when a user theme
+/// is missing one of its preview SVGs. Same logical size as
+/// [`spawn_thumbnail_image`] so chip layout stays stable.
+fn spawn_thumbnail_placeholder(parent: &mut ChildSpawnerCommands) {
+    parent.spawn((
+        Node {
+            width: Val::Px(THUMBNAIL_LOGICAL_WIDTH_PX),
+            height: Val::Px(THUMBNAIL_LOGICAL_HEIGHT_PX),
+            border_radius: BorderRadius::all(Val::Px(RADIUS_SM)),
+            ..default()
+        },
+        BackgroundColor(BG_ELEVATED),
+    ));
+}
+
 /// Status text + manual "Sync Now" button.
 fn sync_row(parent: &mut ChildSpawnerCommands, status_text: &str, font_res: Option<&FontResource>) {
     let status_font = TextFont {
@@ -1943,6 +2226,83 @@ mod tests {
         );
     }
 
+    /// Test 3 of the thumbnail-picker spec: when [`ThemeRegistry`] has
+    /// at least one theme and the [`ThemeThumbnailCache`] holds a
+    /// fully-populated [`ThemeThumbnailPair`] for that theme's id, the
+    /// rendered chip carries a [`ThemeThumbnailMarker`]-tagged
+    /// `ImageNode` for each preview slot.
+    #[test]
+    fn theme_picker_chip_includes_thumbnail_sprite_when_thumbnails_loaded() {
+        use crate::theme::{ThemeEntry, ThemeRegistry, ThemeThumbnailCache, ThemeThumbnailPair};
+
+        let mut app = headless_app_with_focus();
+        // Prime an Assets<Image> resource so we can mint stable handles
+        // for the synthetic thumbnail pair.
+        app.init_resource::<Assets<Image>>();
+        let (ace_handle, back_handle) = {
+            let mut images = app.world_mut().resource_mut::<Assets<Image>>();
+            let ace = images.add(Image::default());
+            let back = images.add(Image::default());
+            (ace, back)
+        };
+        // Inject one theme entry + a matching thumbnail pair.
+        app.insert_resource(ThemeRegistry {
+            entries: vec![ThemeEntry {
+                id: "test_theme".into(),
+                display_name: "Test Theme".into(),
+                manifest_url: "themes://test_theme/theme.ron".into(),
+                meta: crate::theme::ThemeMeta {
+                    id: "test_theme".into(),
+                    name: "Test Theme".into(),
+                    author: "x".into(),
+                    version: "x".into(),
+                    card_aspect: (2, 3),
+                },
+            }],
+        });
+        let mut cache = ThemeThumbnailCache::default();
+        cache.entries.insert(
+            "test_theme".into(),
+            ThemeThumbnailPair {
+                ace: ace_handle.clone(),
+                back: back_handle.clone(),
+            },
+        );
+        app.insert_resource(cache);
+
+        // Open the panel and let the spawn + child-flush systems run.
+        app.world_mut().resource_mut::<SettingsScreen>().0 = true;
+        app.update();
+        app.update();
+        app.update();
+
+        // Find every ImageNode tagged with ThemeThumbnailMarker — the
+        // theme picker chip for "test_theme" must contribute exactly
+        // two of them (ace + back).
+        let thumbnail_count = app
+            .world_mut()
+            .query_filtered::<&ImageNode, With<ThemeThumbnailMarker>>()
+            .iter(app.world())
+            .count();
+        assert!(
+            thumbnail_count >= 2,
+            "expected at least one ace + back thumbnail (2 sprites); got {thumbnail_count}"
+        );
+
+        // Spot-check: at least one thumbnail's image handle matches one
+        // of the ones we inserted into the cache. This guards against a
+        // future refactor that accidentally clones the wrong handle.
+        let any_matches = app
+            .world_mut()
+            .query_filtered::<&ImageNode, With<ThemeThumbnailMarker>>()
+            .iter(app.world())
+            .any(|node| node.image == ace_handle || node.image == back_handle);
+        assert!(
+            any_matches,
+            "at least one rendered thumbnail must reuse the cached handle"
+        );
+    }
+
     // -----------------------------------------------------------------------
     // Window geometry persistence
     // -----------------------------------------------------------------------

solitaire_engine/src/stats_plugin.rs

@@ -11,8 +11,8 @@ use std::path::PathBuf;
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
 use solitaire_data::{
-    load_stats_from, save_stats_to, stats_file_path, PlayerProgress, StatsExt, StatsSnapshot,
+    load_replay_history_from, load_stats_from, replay_history_path, save_stats_to,
-    WEEKLY_GOALS,
+    stats_file_path, PlayerProgress, Replay, ReplayHistory, StatsExt, StatsSnapshot, WEEKLY_GOALS,
 };
 
 use crate::auto_complete_plugin::AutoCompleteState;
@@ -58,6 +58,66 @@ pub struct StatsScreen;
 #[derive(Component, Debug)]
 pub struct StatsCell;
 
+/// Resource holding the rolling [`ReplayHistory`] of recent winning
+/// replays.
+///
+/// Populated from `<data_dir>/solitaire_quest/replays.json` at startup
+/// and refreshed in-place whenever the engine writes a new winning
+/// replay so the Stats overlay's selector always reflects the current
+/// on-disk history.
+///
+/// `replays[0]` is the most recent win — the Stats overlay's selector
+/// defaults to that entry and lets the player step backwards through
+/// up to [`solitaire_data::REPLAY_HISTORY_CAP`] older entries.
+#[derive(Resource, Debug, Default, Clone)]
+pub struct ReplayHistoryResource(pub ReplayHistory);
+
+/// Currently-selected index into [`ReplayHistoryResource::0`].`replays`.
+///
+/// `0` is the most recent win and is the default on every modal open.
+/// The Prev / Next chips wrap-around within the bounds of the current
+/// history so the selector is always sat on a valid replay (or on `0`
+/// when the history is empty — the chips paint disabled in that case).
+#[derive(Resource, Debug, Default, Clone, Copy)]
+pub struct SelectedReplayIndex(pub usize);
+
+/// Persistence path for the rolling replay history file
+/// (`replays.json`). `None` disables I/O — used by tests and by
+/// `StatsPlugin::headless`.
+#[derive(Resource, Debug, Clone)]
+pub struct LatestReplayPath(pub Option<PathBuf>);
+
+/// Marker on the "Watch replay" button inside the Stats modal. Clicking
+/// it starts in-engine playback of the selected replay — see
+/// [`handle_watch_replay_button`].
+#[derive(Component, Debug)]
+pub struct WatchReplayButton;
+
+/// Marker on the selector's "Previous replay" chip — steps the
+/// selection backwards (toward older replays) within
+/// [`ReplayHistoryResource`].
+#[derive(Component, Debug)]
+pub struct ReplayPrevButton;
+
+/// Marker on the selector's "Next replay" chip — steps the selection
+/// forwards (toward more recent replays).
+#[derive(Component, Debug)]
+pub struct ReplayNextButton;
+
+/// Marker on the selector's `"Replay N / M"` caption text node so the
+/// repaint system can rewrite the label as the selection changes.
+#[derive(Component, Debug)]
+pub struct ReplaySelectorCaption;
+
+/// Marker component on each per-mode bests row in the stats overlay.
+///
+/// One row per supported [`solitaire_core::game_state::GameMode`] (Classic,
+/// Zen, Challenge — Time Attack and Daily are intentionally excluded; see
+/// `StatsSnapshot` doc comments). Tests query by this marker to assert the
+/// per-mode section rendered.
+#[derive(Component, Debug)]
+pub struct PerModeBestsRow;
+
 /// Registers stats resources, update systems, and the UI toggle.
 pub struct StatsPlugin {
     /// Where to persist stats. `None` disables all file I/O (for tests).
@@ -87,8 +147,20 @@ impl Plugin for StatsPlugin {
             Some(path) => load_stats_from(path),
             None => StatsSnapshot::default(),
         };
+        // Replay file lives next to stats.json — when the StatsPlugin
+        // is in headless mode (storage_path = None), we mirror that
+        // policy and disable replay I/O too. Otherwise resolve the
+        // platform-default path via `replay_history_path()`.
+        let replay_path = self.storage_path.as_ref().and(replay_history_path());
+        let initial_history = replay_path
+            .as_deref()
+            .and_then(load_replay_history_from)
+            .unwrap_or_default();
         app.insert_resource(StatsResource(loaded))
             .insert_resource(StatsStoragePath(self.storage_path.clone()))
+            .insert_resource(ReplayHistoryResource(initial_history))
+            .init_resource::<SelectedReplayIndex>()
+            .insert_resource(LatestReplayPath(replay_path))
             .add_message::<GameWonEvent>()
             .add_message::<NewGameRequestEvent>()
             .add_message::<ForfeitEvent>()
@@ -114,10 +186,169 @@ impl Plugin for StatsPlugin {
                 handle_forfeit.before(GameMutation),
             )
             .add_systems(Update, toggle_stats_screen.after(GameMutation))
-            .add_systems(Update, handle_stats_close_button);
+            .add_systems(Update, handle_stats_close_button)
+            .add_systems(
+                Update,
+                refresh_replay_history_on_win.after(GameMutation),
+            )
+            .add_systems(Update, handle_watch_replay_button)
+            .add_systems(
+                Update,
+                (handle_replay_selector_buttons, repaint_replay_selector_caption).chain(),
+            );
     }
 }
 
+/// After a win, the engine has just appended a fresh winning replay to
+/// the rolling history file. Re-load it so the next time the player
+/// opens the Stats overlay the selector reflects the new entry, and
+/// reset [`SelectedReplayIndex`] to `0` so the default selection is the
+/// just-recorded win.
+fn refresh_replay_history_on_win(
+    mut wins: MessageReader<GameWonEvent>,
+    mut history: ResMut<ReplayHistoryResource>,
+    mut selected: ResMut<SelectedReplayIndex>,
+    path: Res<LatestReplayPath>,
+) {
+    // Only re-load when at least one win actually fired.
+    if wins.read().next().is_none() {
+        return;
+    }
+    let Some(p) = path.0.as_deref() else {
+        return;
+    };
+    history.0 = load_replay_history_from(p).unwrap_or_default();
+    // Snap the selector back to the most recent win — that's the one
+    // the player just earned.
+    selected.0 = 0;
+}
+
+/// Click handler for the "Watch replay" button.
+///
+/// Starts in-engine replay playback for the currently-selected entry in
+/// [`ReplayHistoryResource`] (per [`SelectedReplayIndex`]). If the
+/// history is empty or the selector points past the end (defensive
+/// guard), surfaces an [`InfoToastEvent`] instead. The playback path
+/// resets the live game to the recorded deal and ticks through the
+/// move list via [`crate::replay_playback`]; the
+/// [`crate::replay_overlay`] banner surfaces while playback runs.
+fn handle_watch_replay_button(
+    mut commands: Commands,
+    buttons: Query<&Interaction, (With<WatchReplayButton>, Changed<Interaction>)>,
+    history: Res<ReplayHistoryResource>,
+    selected: Res<SelectedReplayIndex>,
+    playback: Option<ResMut<crate::replay_playback::ReplayPlaybackState>>,
+    mut toast: MessageWriter<InfoToastEvent>,
+) {
+    if !buttons.iter().any(|i| *i == Interaction::Pressed) {
+        return;
+    }
+    let chosen = history.0.replays.get(selected.0);
+    match (chosen, playback) {
+        (Some(replay), Some(mut playback)) => {
+            crate::replay_playback::start_replay_playback(
+                &mut commands,
+                &mut playback,
+                replay.clone(),
+            );
+        }
+        (Some(replay), None) => {
+            // ReplayPlaybackPlugin not registered (headless test
+            // fixtures); fall back to a descriptive toast.
+            toast.write(InfoToastEvent(format!(
+                "Replay ready ({})",
+                format_replay_caption(replay)
+            )));
+        }
+        (None, _) => {
+            toast.write(InfoToastEvent(
+                "No replay recorded yet \u{2014} win a game first.".to_string(),
+            ));
+        }
+    }
+}
+
+/// Click handler for the Prev / Next chips on the Stats overlay's
+/// replay selector. Steps [`SelectedReplayIndex`] within the bounds of
+/// the current [`ReplayHistoryResource`]; selection wraps so the
+/// chooser is always sat on a valid replay.
+///
+/// No-op when the history is empty — the selector chips paint disabled
+/// in that case but a defensive bounds check here keeps things tidy if
+/// the click somehow lands.
+fn handle_replay_selector_buttons(
+    prev: Query<&Interaction, (With<ReplayPrevButton>, Changed<Interaction>)>,
+    next: Query<&Interaction, (With<ReplayNextButton>, Changed<Interaction>)>,
+    history: Res<ReplayHistoryResource>,
+    mut selected: ResMut<SelectedReplayIndex>,
+) {
+    let len = history.0.replays.len();
+    if len == 0 {
+        return;
+    }
+    let prev_pressed = prev.iter().any(|i| *i == Interaction::Pressed);
+    let next_pressed = next.iter().any(|i| *i == Interaction::Pressed);
+    if prev_pressed {
+        // Step toward older replays — wrap to the oldest when at the
+        // newest (index 0).
+        selected.0 = if selected.0 == 0 { len - 1 } else { selected.0 - 1 };
+    }
+    if next_pressed {
+        // Step toward more recent replays — wrap to the newest when at
+        // the oldest.
+        selected.0 = (selected.0 + 1) % len;
+    }
+}
+
+/// Live-update the `"Replay N / M"` caption text as the selector
+/// changes. The caption sits next to the Prev / Next chips above the
+/// Watch button so the player can see at a glance which replay they're
+/// about to watch.
+fn repaint_replay_selector_caption(
+    history: Res<ReplayHistoryResource>,
+    selected: Res<SelectedReplayIndex>,
+    mut q: Query<&mut Text, With<ReplaySelectorCaption>>,
+) {
+    if !history.is_changed() && !selected.is_changed() {
+        return;
+    }
+    for mut text in &mut q {
+        **text = replay_selector_caption(selected.0, history.0.replays.len());
+    }
+}
+
+/// 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}"`.
+///
+/// `index` is zero-based as it's stored in [`SelectedReplayIndex`].
+/// The display flips it to a one-based ordinal so "Replay 1" reads as
+/// "the most recent win" — matching the mental model the chooser
+/// surfaces.
+pub fn replay_selector_caption(index: usize, total: usize) -> String {
+    if total == 0 {
+        return "No replays".to_string();
+    }
+    // Defensive clamp — the caller is supposed to keep `index` in
+    // range, but a stale selector after a cap-driven truncation
+    // shouldn't crash the renderer.
+    let one_based = index.min(total.saturating_sub(1)) + 1;
+    format!("Replay {one_based} / {total}")
+}
+
+/// Pure helper: render a one-line caption for a [`Replay`] suitable
+/// for the Stats overlay button label and the "Replay loaded" toast.
+///
+/// Format: `"M:SS win on YYYY-MM-DD"`. For a 134-second win recorded
+/// on 2026-05-02, returns `"2:14 win on 2026-05-02"`.
+pub fn format_replay_caption(replay: &Replay) -> String {
+    format!(
+        "{} win on {}",
+        format_duration(replay.time_seconds),
+        replay.recorded_at,
+    )
+}
+
 fn persist(path: &StatsStoragePath, stats: &StatsSnapshot, context: &str) {
     let Some(target) = &path.0 else {
         return;
@@ -140,6 +371,13 @@ fn update_stats_on_win(
         stats
             .0
             .update_on_win(ev.score, ev.time_seconds, &game.0.draw_mode);
+        // Per-mode best score / fastest win — additive on top of the
+        // lifetime totals tracked by `update_on_win`. TimeAttack is a
+        // no-op inside the helper because it has its own session-level
+        // scoring model.
+        stats
+            .0
+            .update_per_mode_bests(ev.score, ev.time_seconds, game.0.mode);
         let new_streak = stats.0.win_streak_current;
         // Fire the streak-milestone event only on the threshold
         // crossing — `prev < threshold && new >= threshold`. This
@@ -247,6 +485,8 @@ fn toggle_stats_screen(
     progress: Option<Res<ProgressResource>>,
     time_attack: Option<Res<TimeAttackResource>>,
     font_res: Option<Res<FontResource>>,
+    latest_replay: Res<ReplayHistoryResource>,
+    selected_index: Res<SelectedReplayIndex>,
     screens: Query<Entity, With<StatsScreen>>,
 ) {
     let button_clicked = requests.read().count() > 0;
@@ -256,12 +496,14 @@ 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,
         );
     }
 }
@@ -287,6 +529,7 @@ fn spawn_stats_screen(
     progress: Option<&PlayerProgress>,
     time_attack: Option<&TimeAttackResource>,
     font_res: Option<&FontResource>,
+    latest_replay: Option<&Replay>,
 ) {
     // --- primary stat cells ---
     // First-launch zero-state: when no games have been played yet, render
@@ -361,6 +604,46 @@ fn spawn_stats_screen(
             spawn_stat_cell(grid, &best_streak_str, "Best Streak");
         });
 
+        // --- per-mode bests section ---
+        // Three rows, one per supported mode. Time Attack uses session-level
+        // scoring (count of wins inside a 10-minute window) so a per-game
+        // best wouldn't compose; Daily uses Classic scoring and so already
+        // contributes to the Classic row.
+        card.spawn((
+            Text::new("Per-mode bests"),
+            font_section.clone(),
+            TextColor(STATE_INFO),
+        ));
+        card.spawn(Node {
+            flex_direction: FlexDirection::Column,
+            width: Val::Percent(100.0),
+            row_gap: VAL_SPACE_2,
+            ..default()
+        })
+        .with_children(|column| {
+            spawn_per_mode_bests_row(
+                column,
+                "Classic",
+                stats.classic_best_score,
+                stats.classic_fastest_win_seconds,
+                &font_row,
+            );
+            spawn_per_mode_bests_row(
+                column,
+                "Zen",
+                stats.zen_best_score,
+                stats.zen_fastest_win_seconds,
+                &font_row,
+            );
+            spawn_per_mode_bests_row(
+                column,
+                "Challenge",
+                stats.challenge_best_score,
+                stats.challenge_fastest_win_seconds,
+                &font_row,
+            );
+        });
+
         // --- progression section ---
         if let Some(p) = progress {
             card.spawn((
@@ -435,7 +718,34 @@ fn spawn_stats_screen(
                 ));
             }
 
+        // --- Latest replay caption ---
+        // Surfaces the most recent winning game so the player can spot
+        // whether their last victory has been recorded. The Watch
+        // Replay action below is what the player clicks to revisit it.
+        let replay_caption = match latest_replay {
+            Some(r) => format!("Latest win: {}", format_replay_caption(r)),
+            None => "No replay recorded yet \u{2014} win a game first.".to_string(),
+        };
+        card.spawn((
+            Text::new(replay_caption),
+            font_row.clone(),
+            TextColor(TEXT_SECONDARY),
+        ));
+
         spawn_modal_actions(card, |actions| {
+            // The Watch Replay button is always rendered so the
+            // affordance is discoverable from a fresh install. When no
+            // replay exists, the click handler surfaces a clear
+            // "No replay recorded yet" toast rather than silently
+            // doing nothing.
+            spawn_modal_button(
+                actions,
+                WatchReplayButton,
+                "Watch replay",
+                None,
+                ButtonVariant::Secondary,
+                font_res,
+            );
             spawn_modal_button(
                 actions,
                 StatsCloseButton,
@@ -448,6 +758,74 @@ fn spawn_stats_screen(
     });
 }
 
+/// Spawn one row of the "Per-mode bests" section: the mode label on the
+/// left, then the best-score and best-time readouts right-aligned. Each
+/// row is tagged with [`PerModeBestsRow`] so tests can count them.
+///
+/// `best_score == 0` and `fastest_win_seconds == 0` both render as an
+/// em-dash, consistent with the first-launch zero-state treatment used
+/// by the primary cells above.
+fn spawn_per_mode_bests_row(
+    parent: &mut ChildSpawnerCommands,
+    mode_label: &str,
+    best_score: u32,
+    fastest_win_seconds: u64,
+    font_row: &TextFont,
+) {
+    let dash = "\u{2014}".to_string();
+    let score_str = if best_score == 0 {
+        format!("Best {dash}")
+    } else {
+        format!("Best {best_score}")
+    };
+    let time_str = if fastest_win_seconds == 0 {
+        format!("Best time {dash}")
+    } else {
+        format!("Best time {}", format_duration(fastest_win_seconds))
+    };
+
+    parent
+        .spawn((
+            PerModeBestsRow,
+            Node {
+                flex_direction: FlexDirection::Row,
+                align_items: AlignItems::Center,
+                justify_content: JustifyContent::SpaceBetween,
+                width: Val::Percent(100.0),
+                column_gap: VAL_SPACE_3,
+                ..default()
+            },
+        ))
+        .with_children(|row| {
+            // Mode label on the left.
+            row.spawn((
+                Text::new(mode_label.to_string()),
+                font_row.clone(),
+                TextColor(TEXT_PRIMARY),
+            ));
+            // Right-aligned readouts grouped together.
+            row.spawn(Node {
+                flex_direction: FlexDirection::Row,
+                align_items: AlignItems::Center,
+                justify_content: JustifyContent::FlexEnd,
+                column_gap: VAL_SPACE_3,
+                ..default()
+            })
+            .with_children(|readouts| {
+                readouts.spawn((
+                    Text::new(score_str),
+                    font_row.clone(),
+                    TextColor(ACCENT_PRIMARY),
+                ));
+                readouts.spawn((
+                    Text::new(time_str),
+                    font_row.clone(),
+                    TextColor(TEXT_SECONDARY),
+                ));
+            });
+        });
+}
+
 /// Spawn a single stat cell: a large value label on top and a small
 /// descriptor below, inside a fixed-min-width column with a subtle
 /// border. Recoloured to use ui_theme tokens — the prior 6%-alpha-white
@@ -710,6 +1088,67 @@ mod tests {
         );
     }
 
+    #[test]
+    fn stats_screen_renders_three_per_mode_bests_rows() {
+        // Open the Stats overlay and assert three [`PerModeBestsRow`]
+        // entities exist — one per supported [`GameMode`] (Classic, Zen,
+        // Challenge — Time Attack and Daily are excluded by design).
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<ButtonInput<KeyCode>>()
+            .press(KeyCode::KeyS);
+        app.update();
+
+        let row_count = app
+            .world_mut()
+            .query::<&PerModeBestsRow>()
+            .iter(app.world())
+            .count();
+        assert_eq!(
+            row_count, 3,
+            "expected three per-mode bests rows (Classic, Zen, Challenge), got {row_count}"
+        );
+    }
+
+    #[test]
+    fn classic_win_event_updates_classic_best_score() {
+        // Default mode is Classic — a win event should populate the
+        // Classic per-mode bests but leave Zen and Challenge at zero.
+        let mut app = headless_app();
+        app.world_mut().write_message(GameWonEvent {
+            score: 1500,
+            time_seconds: 180,
+        });
+        app.update();
+
+        let stats = &app.world().resource::<StatsResource>().0;
+        assert_eq!(stats.classic_best_score, 1500);
+        assert_eq!(stats.classic_fastest_win_seconds, 180);
+        assert_eq!(stats.zen_best_score, 0);
+        assert_eq!(stats.challenge_best_score, 0);
+    }
+
+    #[test]
+    fn zen_win_event_updates_zen_best_score_only() {
+        let mut app = headless_app();
+        app.world_mut()
+            .resource_mut::<crate::resources::GameStateResource>()
+            .0
+            .mode = solitaire_core::game_state::GameMode::Zen;
+
+        app.world_mut().write_message(GameWonEvent {
+            score: 1800,
+            time_seconds: 600,
+        });
+        app.update();
+
+        let stats = &app.world().resource::<StatsResource>().0;
+        assert_eq!(stats.zen_best_score, 1800);
+        assert_eq!(stats.zen_fastest_win_seconds, 600);
+        assert_eq!(stats.classic_best_score, 0);
+        assert_eq!(stats.challenge_best_score, 0);
+    }
+
     #[test]
     fn pressing_s_twice_closes_stats_screen() {
         let mut app = headless_app();

solitaire_engine/src/sync_plugin.rs

@@ -20,14 +20,15 @@ use uuid::Uuid;
 
 use solitaire_data::{
     save_achievements_to, save_progress_to, save_stats_to, AchievementRecord, PlayerProgress,
-    StatsSnapshot, SyncError, SyncProvider,
+    Replay, StatsSnapshot, SyncError, SyncProvider,
 };
 use solitaire_sync::{merge, SyncPayload, SyncResponse};
 
 use crate::achievement_plugin::{AchievementsResource, AchievementsStoragePath};
-use crate::events::{ManualSyncRequestEvent, SyncCompleteEvent};
+use crate::events::{GameWonEvent, ManualSyncRequestEvent, SyncCompleteEvent};
+use crate::game_plugin::RecordingReplay;
 use crate::progress_plugin::{ProgressResource, ProgressStoragePath};
-use crate::resources::{SyncStatus, SyncStatusResource};
+use crate::resources::{GameStateResource, SyncStatus, SyncStatusResource};
 use crate::stats_plugin::{StatsResource, StatsStoragePath};
 
 // ---------------------------------------------------------------------------
@@ -96,7 +97,10 @@ impl Plugin for SyncPlugin {
             .add_message::<ManualSyncRequestEvent>()
             .add_message::<SyncCompleteEvent>()
             .add_systems(Startup, start_pull)
-            .add_systems(Update, (poll_pull_result, handle_manual_sync_request))
+            .add_systems(
+                Update,
+                (poll_pull_result, handle_manual_sync_request, push_replay_on_win),
+            )
             .add_systems(Last, push_on_exit);
     }
 }
@@ -263,6 +267,51 @@ fn push_on_exit(
     }
 }
 
+/// Update-schedule system: on each `GameWonEvent` push the just-completed
+/// replay to the active sync backend so it's available for web playback.
+///
+/// Spawned as a fire-and-forget task on `AsyncComputeTaskPool` — the game
+/// loop never blocks on the network round-trip. Errors are logged but
+/// never surfaced to the UI; failure to upload is non-fatal because the
+/// replay is also persisted locally by `game_plugin::record_replay_on_win`,
+/// so the player can still review it on the next login. `LocalOnlyProvider`'s
+/// `UnsupportedPlatform` is silently absorbed in the same way the
+/// `push_on_exit` path handles it.
+fn push_replay_on_win(
+    mut wins: MessageReader<GameWonEvent>,
+    provider: Res<SyncProviderResource>,
+    game: Res<GameStateResource>,
+    recording: Res<RecordingReplay>,
+) {
+    for ev in wins.read() {
+        // Empty-recording guard mirrors `record_replay_on_win` —
+        // synthesised win events from XP / streak tests must not trigger
+        // a server upload.
+        if recording.moves.is_empty() {
+            continue;
+        }
+        let replay = Replay::new(
+            game.0.seed,
+            game.0.draw_mode.clone(),
+            game.0.mode,
+            ev.time_seconds,
+            ev.score,
+            Utc::now().date_naive(),
+            recording.moves.clone(),
+        );
+        let provider = provider.0.clone();
+        AsyncComputeTaskPool::get()
+            .spawn(async move {
+                match provider.push_replay(&replay).await {
+                    Ok(()) => {}
+                    Err(SyncError::UnsupportedPlatform) => {}
+                    Err(e) => warn!("replay upload failed: {e}"),
+                }
+            })
+            .detach();
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Helpers
 // ---------------------------------------------------------------------------

solitaire_engine/src/theme/mod.rs

@@ -31,7 +31,10 @@ use solitaire_core::card::{Rank, Suit};
 pub use importer::{import_theme, import_theme_into, ImportError, ThemeId};
 pub use loader::{CardThemeLoader, CardThemeLoaderError};
 pub use manifest::ThemeManifest;
-pub use plugin::{set_theme, ActiveTheme, ThemePlugin};
+pub use plugin::{
+    ensure_theme_thumbnails, set_theme, ActiveTheme, ThemePlugin, ThemeThumbnailCache,
+    ThemeThumbnailPair, THEME_THUMBNAIL_HEIGHT_PX, THEME_THUMBNAIL_WIDTH_PX,
+};
 pub use registry::{
     build_registry, refresh_registry, ThemeEntry, ThemeRegistry, ThemeRegistryPlugin,
 };

solitaire_engine/src/theme/plugin.rs

@@ -8,24 +8,82 @@
 //! exposed for tests and for any embedder that wants to load an
 //! alternative theme manually.
 
+use std::collections::HashMap;
+
 use bevy::asset::AssetEvent;
 use bevy::ecs::message::MessageReader;
+use bevy::math::UVec2;
 use bevy::prelude::*;
 use solitaire_core::card::{Rank, Suit};
 
-use crate::assets::DEFAULT_THEME_MANIFEST_URL;
+use crate::assets::{
+    default_theme_svg_bytes, rasterize_svg, user_theme_dir, DEFAULT_THEME_MANIFEST_URL,
+};
 use crate::card_plugin::CardImageSet;
 use crate::events::StateChangedEvent;
 
 use super::loader::CardThemeLoader;
+use super::registry::ThemeRegistry;
 use super::{CardKey, CardTheme};
 
+/// Width (logical px) of one Settings → Cosmetic theme-picker
+/// thumbnail. A 2:3 card aspect at 100×140 keeps each chip a small
+/// glanceable preview without bloating the picker row.
+pub const THEME_THUMBNAIL_WIDTH_PX: u32 = 100;
+/// Height counterpart to [`THEME_THUMBNAIL_WIDTH_PX`].
+pub const THEME_THUMBNAIL_HEIGHT_PX: u32 = 140;
+
 /// Resource pointing at the currently-active card theme. Populated on
 /// startup with the bundled default theme and replaced by [`set_theme`]
 /// when the player switches.
 #[derive(Resource, Debug)]
 pub struct ActiveTheme(pub Handle<CardTheme>);
 
+/// One pair of preview-sized `Handle<Image>` for the Settings picker:
+/// the theme's Ace of Spades and its card back.
+///
+/// Either handle may be [`Handle::default`] when the underlying SVG
+/// could not be located (e.g. a user theme that ships only a partial
+/// set of files). The picker UI treats the default-handle case as
+/// "render a placeholder swatch instead of an image" so a broken
+/// theme can never crash the panel.
+#[derive(Debug, Clone, Default)]
+pub struct ThemeThumbnailPair {
+    /// Rasterised `spades_ace.svg` of the theme.
+    pub ace: Handle<Image>,
+    /// Rasterised `back.svg` of the theme.
+    pub back: Handle<Image>,
+}
+
+impl ThemeThumbnailPair {
+    /// Returns `true` only when *both* preview slots resolve to a
+    /// non-default handle — a theme with at least one missing SVG is
+    /// considered incomplete and renders the placeholder for the
+    /// missing slot.
+    pub fn is_fully_populated(&self) -> bool {
+        self.ace != Handle::default() && self.back != Handle::default()
+    }
+}
+
+/// Resource caching one [`ThemeThumbnailPair`] per registered theme,
+/// keyed by `ThemeMeta::id`.
+///
+/// Populated lazily by [`ensure_theme_thumbnails`] whenever the
+/// [`ThemeRegistry`] grows or changes. The Settings panel reads from
+/// this cache by id and falls back to the placeholder rendering path
+/// when an entry is missing.
+#[derive(Resource, Debug, Default)]
+pub struct ThemeThumbnailCache {
+    pub entries: HashMap<String, ThemeThumbnailPair>,
+}
+
+impl ThemeThumbnailCache {
+    /// Returns the cached pair for `theme_id`, if any.
+    pub fn get(&self, theme_id: &str) -> Option<&ThemeThumbnailPair> {
+        self.entries.get(theme_id)
+    }
+}
+
 /// Bevy plugin that loads the default theme and keeps `CardImageSet`
 /// in sync with `Assets<CardTheme>`.
 ///
@@ -45,6 +103,7 @@ pub struct ThemePlugin;
 impl Plugin for ThemePlugin {
     fn build(&self, app: &mut App) {
         app.init_asset::<CardTheme>()
+            .init_resource::<ThemeThumbnailCache>()
             .register_asset_loader(crate::assets::SvgLoader)
             .register_asset_loader(CardThemeLoader)
             .add_systems(Startup, load_initial_theme)
@@ -53,6 +112,7 @@ impl Plugin for ThemePlugin {
                 (
                     sync_card_image_set_with_active_theme,
                     react_to_settings_theme_change,
+                    ensure_theme_thumbnails,
                 ),
             );
     }
@@ -231,6 +291,104 @@ pub fn set_theme(
     handle
 }
 
+// ---------------------------------------------------------------------------
+// Picker-thumbnail generation
+// ---------------------------------------------------------------------------
+
+/// Filename of the canonical "preview face" SVG inside a theme — the
+/// Ace of Spades. Matches `CardKey::manifest_name(Spades, Ace)` so the
+/// path resolves the same way whether we're reading from disk or from
+/// the bundled-default lookup table.
+const PREVIEW_FACE_FILENAME: &str = "spades_ace.svg";
+
+/// Filename of the back SVG inside a theme.
+const PREVIEW_BACK_FILENAME: &str = "back.svg";
+
+/// Resolves the SVG bytes for one preview file (`back.svg` or
+/// `spades_ace.svg`) belonging to the named theme.
+///
+/// - For the bundled `default` theme, reads from the embedded
+///   `DEFAULT_THEME_SVGS` table via [`default_theme_svg_bytes`]. No
+///   filesystem I/O.
+/// - For any user theme, reads from `<user_theme_dir>/<id>/<filename>`.
+///   Returns `None` for any I/O failure (file missing, permission
+///   denied, etc.) — the caller treats `None` as "render placeholder".
+fn read_theme_preview_svg_bytes(theme_id: &str, filename: &str) -> Option<Vec<u8>> {
+    if theme_id == "default" {
+        return default_theme_svg_bytes(filename).map(|b| b.to_vec());
+    }
+    let path = user_theme_dir().join(theme_id).join(filename);
+    std::fs::read(&path).ok()
+}
+
+/// Pure helper: rasterises one SVG preview byte slice at the picker's
+/// thumbnail dimensions, inserts the resulting `Image` into
+/// `Assets<Image>`, and returns the new handle. Returns
+/// [`Handle::default`] if rasterisation fails (malformed SVG, etc.) so
+/// the picker can render a placeholder for broken themes without
+/// crashing.
+fn rasterize_preview_to_handle(
+    svg_bytes: &[u8],
+    images: &mut Assets<Image>,
+) -> Handle<Image> {
+    let target = UVec2::new(THEME_THUMBNAIL_WIDTH_PX, THEME_THUMBNAIL_HEIGHT_PX);
+    match rasterize_svg(svg_bytes, target) {
+        Ok(image) => images.add(image),
+        Err(err) => {
+            warn!("theme thumbnail rasterise failed: {err}");
+            Handle::default()
+        }
+    }
+}
+
+/// Builds a [`ThemeThumbnailPair`] for a single theme. Either handle
+/// is [`Handle::default`] when the matching SVG could not be located
+/// or rasterised.
+fn generate_thumbnail_pair_for(
+    theme_id: &str,
+    images: &mut Assets<Image>,
+) -> ThemeThumbnailPair {
+    let ace = read_theme_preview_svg_bytes(theme_id, PREVIEW_FACE_FILENAME)
+        .map(|b| rasterize_preview_to_handle(&b, images))
+        .unwrap_or_default();
+    let back = read_theme_preview_svg_bytes(theme_id, PREVIEW_BACK_FILENAME)
+        .map(|b| rasterize_preview_to_handle(&b, images))
+        .unwrap_or_default();
+    ThemeThumbnailPair { ace, back }
+}
+
+/// System that generates a [`ThemeThumbnailPair`] for every registered
+/// theme that doesn't yet have one in [`ThemeThumbnailCache`].
+///
+/// Runs each frame but the early-exit check (`already cached?`) keeps
+/// the steady-state cost to a single hash lookup per theme. Generation
+/// itself only happens once per theme — the SVGs are rasterised and
+/// inserted into `Assets<Image>` and the handles cached forever.
+///
+/// Lazy-on-first-pass beats Startup-only for two reasons:
+///
+/// - The `ThemeRegistry` is built by a different `Startup` system, and
+///   Bevy doesn't guarantee inter-system Startup ordering without
+///   explicit `.after()` chaining. Polling each Update tick removes
+///   the dependency.
+/// - The future `refresh_registry` path (used after a successful
+///   theme import in Phase 7) adds entries mid-session — this system
+///   picks them up automatically without any extra wiring.
+pub fn ensure_theme_thumbnails(
+    registry: Option<Res<ThemeRegistry>>,
+    mut cache: ResMut<ThemeThumbnailCache>,
+    mut images: ResMut<Assets<Image>>,
+) {
+    let Some(registry) = registry else { return };
+    for entry in registry.iter() {
+        if cache.entries.contains_key(&entry.id) {
+            continue;
+        }
+        let pair = generate_thumbnail_pair_for(&entry.id, &mut images);
+        cache.entries.insert(entry.id.clone(), pair);
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -352,4 +510,120 @@ mod tests {
         let url2 = format!("themes://{}/theme.ron", "user_uploaded");
         assert_eq!(url2, "themes://user_uploaded/theme.ron");
     }
+
+    /// Test 1: the bundled default theme always has embedded SVG bytes
+    /// available, so calling `generate_thumbnail_pair_for("default", …)`
+    /// must produce two non-default `Handle<Image>` slots.
+    #[test]
+    fn theme_thumbnails_generated_for_default_theme() {
+        let mut images = Assets::<Image>::default();
+        let pair = generate_thumbnail_pair_for("default", &mut images);
+        assert!(
+            pair.is_fully_populated(),
+            "default theme must yield both ace + back thumbnail handles"
+        );
+        // And the underlying images must actually exist in the assets
+        // collection — the handles are real, not dangling.
+        assert!(images.get(&pair.ace).is_some(), "ace image must be inserted");
+        assert!(images.get(&pair.back).is_some(), "back image must be inserted");
+    }
+
+    /// Test 2: when a theme is registered but its preview SVGs are not
+    /// available on disk (a broken user-supplied theme), thumbnail
+    /// generation must NOT panic and must leave the missing slots as
+    /// the default handle so the picker UI can render its placeholder.
+    #[test]
+    fn theme_thumbnails_handle_missing_svg_gracefully() {
+        let mut images = Assets::<Image>::default();
+        // A theme id that definitely has no files on disk under the
+        // user_theme_dir (the directory may not even exist on a
+        // fresh test machine). The function reads the filesystem
+        // lazily and silently returns None on I/O failures — no
+        // panic, no rasterise attempt.
+        let pair = generate_thumbnail_pair_for(
+            "this-theme-does-not-exist-on-disk-for-testing",
+            &mut images,
+        );
+        assert_eq!(
+            pair.ace,
+            Handle::default(),
+            "missing ace.svg must yield Handle::default placeholder"
+        );
+        assert_eq!(
+            pair.back,
+            Handle::default(),
+            "missing back.svg must yield Handle::default placeholder"
+        );
+        assert!(
+            !pair.is_fully_populated(),
+            "incomplete pair must report not-fully-populated"
+        );
+    }
+
+    /// `read_theme_preview_svg_bytes` for the default theme always
+    /// returns embedded bytes for the canonical preview pair —
+    /// covering the happy-path branch of the helper.
+    #[test]
+    fn read_default_theme_preview_returns_some_for_canonical_files() {
+        assert!(
+            read_theme_preview_svg_bytes("default", PREVIEW_BACK_FILENAME).is_some(),
+            "default theme back.svg must be embedded"
+        );
+        assert!(
+            read_theme_preview_svg_bytes("default", PREVIEW_FACE_FILENAME).is_some(),
+            "default theme spades_ace.svg must be embedded"
+        );
+    }
+
+    /// `ensure_theme_thumbnails` is idempotent: calling it twice with
+    /// the same registry must not regenerate or replace already-cached
+    /// entries. This guards against the per-frame Update tick churning
+    /// new `Handle<Image>` allocations and growing `Assets<Image>`
+    /// without bound.
+    #[test]
+    fn ensure_theme_thumbnails_caches_after_first_run() {
+        let mut app = App::new();
+        app.add_plugins(MinimalPlugins);
+        app.init_resource::<Assets<Image>>();
+        app.init_resource::<ThemeThumbnailCache>();
+        app.insert_resource(ThemeRegistry {
+            entries: vec![crate::theme::ThemeEntry {
+                id: "default".into(),
+                display_name: "Default".into(),
+                manifest_url: crate::assets::DEFAULT_THEME_MANIFEST_URL.into(),
+                meta: ThemeMeta {
+                    id: "default".into(),
+                    name: "Default".into(),
+                    author: "x".into(),
+                    version: "x".into(),
+                    card_aspect: (2, 3),
+                },
+            }],
+        });
+        app.add_systems(Update, ensure_theme_thumbnails);
+
+        // First tick generates the entry.
+        app.update();
+        let first_ace = app
+            .world()
+            .resource::<ThemeThumbnailCache>()
+            .get("default")
+            .map(|p| p.ace.clone())
+            .expect("default theme thumbnail must exist after one tick");
+
+        // Second tick must NOT replace the cached handle.
+        app.update();
+        let second_ace = app
+            .world()
+            .resource::<ThemeThumbnailCache>()
+            .get("default")
+            .map(|p| p.ace.clone())
+            .expect("default theme thumbnail must still exist");
+
+        assert_eq!(
+            first_ace.id(),
+            second_ace.id(),
+            "cached thumbnail handle must be stable across ticks"
+        );
+    }
 }

solitaire_engine/src/time_attack_plugin.rs

@@ -3,9 +3,33 @@
 //! level ≥ `CHALLENGE_UNLOCK_LEVEL`); each win during the session bumps the
 //! counter and auto-deals a fresh game. When the timer expires the session
 //! ends and `TimeAttackEndedEvent` fires.
+//!
+//! ## Persistence
+//!
+//! Classic / Zen / Challenge mid-deals already round-trip through
+//! `game_state.json` (the file carries `mode: GameMode`, so the deal *and*
+//! its mode flag both survive a window close). Time Attack additionally
+//! has session-level state — the 10-minute window remaining and the running
+//! win counter — that lives in [`TimeAttackResource`], not in `GameState`.
+//! That extra state is persisted to the sibling file
+//! `time_attack_session.json` via [`solitaire_data::TimeAttackSession`] so
+//! closing the window mid-Time-Attack does not lose the session.
+//!
+//! The file is written periodically (every ~30 real seconds, mirroring the
+//! game-state auto-save cadence) and on `AppExit`. It is deleted on session
+//! end, on a fresh session start, and on quit-to-menu. Load happens once at
+//! plugin startup; if the persisted window expired during the time the app
+//! was closed, the file is treated as missing.
+
+use std::path::PathBuf;
+use std::time::{SystemTime, UNIX_EPOCH};
 
 use bevy::prelude::*;
 use solitaire_core::game_state::GameMode;
+use solitaire_data::{
+    delete_time_attack_session_at, load_time_attack_session_from, save_time_attack_session_to,
+    time_attack_session_path, TimeAttackSession,
+};
 
 use crate::challenge_plugin::CHALLENGE_UNLOCK_LEVEL;
 use crate::events::{
@@ -33,12 +57,52 @@ pub struct TimeAttackEndedEvent {
     pub wins: u32,
 }
 
+/// Real-world seconds between Time Attack session-state auto-saves.
+///
+/// Mirrors the game-state auto-save cadence in `game_plugin::AUTO_SAVE_INTERVAL_SECS`
+/// so a crash loses at most ~30 s of session-timer progress.
+const TIME_ATTACK_AUTO_SAVE_INTERVAL_SECS: f32 = 30.0;
+
+/// Persistence path for `time_attack_session.json`. `None` disables I/O
+/// (used in headless tests so they don't touch the real data dir).
+#[derive(Resource, Debug, Clone)]
+pub struct TimeAttackSessionPath(pub Option<PathBuf>);
+
+/// Accumulated real-world seconds since the last Time Attack session save.
+/// Exposed as a `Resource` so tests can pre-seed it past the threshold without
+/// needing to control `Time::delta_secs()` (mirrors `game_plugin::AutoSaveTimer`).
+#[derive(Resource, Default)]
+pub struct TimeAttackAutoSaveTimer(pub f32);
+
 /// Implements the 10-minute Time Attack mode: counts down the session timer, tracks wins per session, and fires `TimeAttackEndedEvent` when time expires.
 pub struct TimeAttackPlugin;
 
+impl TimeAttackPlugin {
+    /// Plugin variant with persistence disabled. Use in headless tests to
+    /// avoid touching the real `time_attack_session.json` on disk.
+    pub fn headless() -> Self {
+        Self
+    }
+}
+
 impl Plugin for TimeAttackPlugin {
     fn build(&self, app: &mut App) {
-        app.init_resource::<TimeAttackResource>()
+        let path = time_attack_session_path();
+        // Restore any saved session that hasn't yet expired in real time.
+        // A missing file or an expired window both yield `None`, in which
+        // case the resource keeps its default (inactive) value.
+        let initial_session = path
+            .as_deref()
+            .and_then(load_time_attack_session_from)
+            .map_or_else(TimeAttackResource::default, |s| TimeAttackResource {
+                active: true,
+                remaining_secs: s.remaining_secs,
+                wins: s.wins,
+            });
+
+        app.insert_resource(initial_session)
+            .insert_resource(TimeAttackSessionPath(path))
+            .init_resource::<TimeAttackAutoSaveTimer>()
             .add_message::<TimeAttackEndedEvent>()
             .add_message::<GameWonEvent>()
             .add_message::<NewGameRequestEvent>()
@@ -49,10 +113,13 @@ impl Plugin for TimeAttackPlugin {
                 handle_start_time_attack_request.before(GameMutation),
             )
             .add_systems(Update, advance_time_attack)
-            .add_systems(Update, auto_deal_on_time_attack_win.after(GameMutation));
+            .add_systems(Update, auto_deal_on_time_attack_win.after(GameMutation))
+            .add_systems(Update, auto_save_time_attack_session)
+            .add_systems(Last, save_time_attack_session_on_exit);
     }
 }
 
+#[allow(clippy::too_many_arguments)]
 fn handle_start_time_attack_request(
     keys: Res<ButtonInput<KeyCode>>,
     mut requests: MessageReader<StartTimeAttackRequestEvent>,
@@ -60,6 +127,8 @@ fn handle_start_time_attack_request(
     mut session: ResMut<TimeAttackResource>,
     mut new_game: MessageWriter<NewGameRequestEvent>,
     mut info_toast: MessageWriter<InfoToastEvent>,
+    path: Option<Res<TimeAttackSessionPath>>,
+    mut auto_save_timer: ResMut<TimeAttackAutoSaveTimer>,
 ) {
     // Either T or the HUD Modes-popover "Time Attack" row triggers this.
     let button_clicked = requests.read().count() > 0;
@@ -77,6 +146,18 @@ fn handle_start_time_attack_request(
         remaining_secs: TIME_ATTACK_DURATION_SECS,
         wins: 0,
     };
+    // Reset the auto-save accumulator so the first save lands a full
+    // interval from now, not immediately because of an old residual value
+    // left over from a previous session.
+    auto_save_timer.0 = 0.0;
+    // Delete any leftover persisted session file from a prior run so the
+    // fresh window starts at exactly TIME_ATTACK_DURATION_SECS rather than
+    // resuming whatever the disk happened to hold. Failures here are
+    // logged but never fatal.
+    if let Some(p) = path.as_ref().and_then(|r| r.0.as_deref())
+        && let Err(e) = delete_time_attack_session_at(p) {
+            warn!("time_attack_session: failed to delete stale session: {e}");
+        }
     new_game.write(NewGameRequestEvent {
         seed: None,
         mode: Some(GameMode::TimeAttack),
@@ -89,6 +170,7 @@ fn advance_time_attack(
     mut session: ResMut<TimeAttackResource>,
     mut ended: MessageWriter<TimeAttackEndedEvent>,
     paused: Option<Res<crate::pause_plugin::PausedResource>>,
+    path: Option<Res<TimeAttackSessionPath>>,
 ) {
     if !session.active {
         return;
@@ -102,6 +184,12 @@ fn advance_time_attack(
         session.active = false;
         session.remaining_secs = 0.0;
         ended.write(TimeAttackEndedEvent { wins });
+        // Session ended naturally — delete the persisted file so the next
+        // launch sees no in-progress session.
+        if let Some(p) = path.as_ref().and_then(|r| r.0.as_deref())
+            && let Err(e) = delete_time_attack_session_at(p) {
+                warn!("time_attack_session: failed to delete on expiry: {e}");
+            }
     }
 }
 
@@ -124,6 +212,80 @@ fn auto_deal_on_time_attack_win(
     }
 }
 
+/// Returns the current Unix-seconds wall-clock time, falling back to 0 if
+/// the system time predates the epoch (impossible under any sane clock,
+/// but the fallback keeps the function infallible).
+fn current_unix_secs() -> u64 {
+    SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .map_or(0, |d| d.as_secs())
+}
+
+/// Periodically persists the live `TimeAttackResource` to
+/// `time_attack_session.json` every 30 real-world seconds while a session
+/// is active. The accumulator uses real-clock delta so it keeps ticking
+/// even if the in-game timer is paused — the goal is "if the OS kills the
+/// process now, how much do we lose?" and pause does not change that.
+fn auto_save_time_attack_session(
+    time: Res<Time>,
+    session: Res<TimeAttackResource>,
+    path: Option<Res<TimeAttackSessionPath>>,
+    mut timer: ResMut<TimeAttackAutoSaveTimer>,
+) {
+    if !session.active {
+        return;
+    }
+    timer.0 += time.delta_secs();
+    if timer.0 < TIME_ATTACK_AUTO_SAVE_INTERVAL_SECS {
+        return;
+    }
+    timer.0 -= TIME_ATTACK_AUTO_SAVE_INTERVAL_SECS;
+    let Some(p) = path.as_ref().and_then(|r| r.0.as_deref()) else {
+        return;
+    };
+    let payload = TimeAttackSession {
+        remaining_secs: session.remaining_secs,
+        wins: session.wins,
+        saved_at_unix_secs: current_unix_secs(),
+    };
+    if let Err(e) = save_time_attack_session_to(p, &payload) {
+        warn!("time_attack_session: auto-save failed: {e}");
+    }
+}
+
+/// Last-schedule companion to `game_plugin::save_game_state_on_exit`:
+/// flushes the live session resource to disk on `AppExit` so a graceful
+/// quit does not lose the timer + win count. If the session is inactive
+/// the persisted file is deleted instead, leaving a clean slate for the
+/// next launch.
+fn save_time_attack_session_on_exit(
+    mut exit_events: MessageReader<AppExit>,
+    session: Res<TimeAttackResource>,
+    path: Res<TimeAttackSessionPath>,
+) {
+    if exit_events.is_empty() {
+        return;
+    }
+    exit_events.clear();
+    let Some(p) = path.0.as_deref() else { return };
+
+    if !session.active {
+        if let Err(e) = delete_time_attack_session_at(p) {
+            warn!("time_attack_session: failed to delete on exit: {e}");
+        }
+        return;
+    }
+
+    let payload = TimeAttackSession {
+        remaining_secs: session.remaining_secs,
+        wins: session.wins,
+        saved_at_unix_secs: current_unix_secs(),
+    };
+    if let Err(e) = save_time_attack_session_to(p, &payload) {
+        warn!("time_attack_session: failed to save on exit: {e}");
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -140,6 +302,12 @@ mod tests {
             .add_plugins(ProgressPlugin::headless())
             .add_plugins(TimeAttackPlugin);
         app.init_resource::<ButtonInput<KeyCode>>();
+        // Disable session persistence — tests must not touch the real
+        // ~/.local/share/solitaire_quest/time_attack_session.json.
+        app.insert_resource(TimeAttackSessionPath(None));
+        // The plugin's startup-load hook may have populated TimeAttackResource
+        // from a real on-disk session. Reset it so each test starts inactive.
+        *app.world_mut().resource_mut::<TimeAttackResource>() = TimeAttackResource::default();
         app.update();
         app
     }
@@ -302,4 +470,170 @@ mod tests {
             "TimeAttackEndedEvent must not fire while paused"
         );
     }
+
+    // -----------------------------------------------------------------------
+    // Persistence tests — closing the window mid-Time-Attack must not lose
+    // the session timer or the running win count.
+    // -----------------------------------------------------------------------
+
+    fn tmp_ta_path(name: &str) -> std::path::PathBuf {
+        std::env::temp_dir().join(format!("engine_test_ta_{name}.json"))
+    }
+
+    /// On `AppExit`, an active session must be flushed to disk so the next
+    /// launch can restore it.
+    #[test]
+    fn exit_persists_active_session() {
+        use solitaire_data::load_time_attack_session_from;
+
+        let path = tmp_ta_path("exit_save");
+        let _ = std::fs::remove_file(&path);
+
+        let mut app = headless_app();
+        app.insert_resource(TimeAttackSessionPath(Some(path.clone())));
+        *app.world_mut().resource_mut::<TimeAttackResource>() = TimeAttackResource {
+            active: true,
+            remaining_secs: 240.0,
+            wins: 4,
+        };
+
+        app.world_mut().write_message(AppExit::Success);
+        app.update();
+
+        // Plugin stamps `saved_at_unix_secs` with the current wall clock,
+        // and we load immediately, so wall-clock elapsed is ~0 and the
+        // restored remaining_secs should match what we wrote within a tiny
+        // epsilon (allowing for the test taking a few seconds to run).
+        let loaded =
+            load_time_attack_session_from(&path).expect("file should exist after exit");
+        assert!(
+            (loaded.remaining_secs - 240.0).abs() < 5.0,
+            "remaining_secs must round-trip within 5 s tolerance, got {}",
+            loaded.remaining_secs,
+        );
+        assert_eq!(loaded.wins, 4, "wins must round-trip");
+
+        let _ = std::fs::remove_file(&path);
+    }
+
+    /// On `AppExit` with no active session, any stale persisted file must
+    /// be deleted so the next launch starts clean.
+    #[test]
+    fn exit_clears_persisted_file_when_no_active_session() {
+        let path = tmp_ta_path("exit_clear");
+        // Pre-create a stale file.
+        std::fs::write(&path, b"{\"remaining_secs\":100.0,\"wins\":1,\"saved_at_unix_secs\":0}")
+            .expect("write stale");
+        assert!(path.exists());
+
+        let mut app = headless_app();
+        app.insert_resource(TimeAttackSessionPath(Some(path.clone())));
+        // Default = inactive session.
+        app.world_mut().write_message(AppExit::Success);
+        app.update();
+
+        assert!(!path.exists(), "stale file must be deleted on exit when session is inactive");
+    }
+
+    /// `auto_save_time_attack_session` writes the session once the
+    /// accumulator crosses 30 s while the session is active.
+    #[test]
+    fn auto_save_writes_after_30_seconds() {
+        use solitaire_data::load_time_attack_session_from;
+
+        let path = tmp_ta_path("auto_save_30s");
+        let _ = std::fs::remove_file(&path);
+
+        let mut app = headless_app();
+        app.insert_resource(TimeAttackSessionPath(Some(path.clone())));
+        *app.world_mut().resource_mut::<TimeAttackResource>() = TimeAttackResource {
+            active: true,
+            remaining_secs: 500.0,
+            wins: 2,
+        };
+        // Pre-seed the timer past the threshold so the very next update fires the save.
+        app.insert_resource(TimeAttackAutoSaveTimer(TIME_ATTACK_AUTO_SAVE_INTERVAL_SECS + 0.1));
+        app.update();
+
+        assert!(path.exists(), "auto-save file must exist after timer crosses threshold");
+        let loaded = load_time_attack_session_from(&path).expect("session must load");
+        assert_eq!(loaded.wins, 2);
+
+        let _ = std::fs::remove_file(&path);
+    }
+
+    /// Auto-save is a no-op when no session is active — we should not be
+    /// littering the user's data dir with empty session files just because
+    /// the app was running.
+    #[test]
+    fn auto_save_is_noop_when_session_inactive() {
+        let path = tmp_ta_path("auto_save_noop");
+        let _ = std::fs::remove_file(&path);
+
+        let mut app = headless_app();
+        app.insert_resource(TimeAttackSessionPath(Some(path.clone())));
+        // Session stays at default (inactive). Timer is past threshold.
+        app.insert_resource(TimeAttackAutoSaveTimer(TIME_ATTACK_AUTO_SAVE_INTERVAL_SECS + 0.1));
+        app.update();
+
+        assert!(!path.exists(), "auto-save must not fire when session is inactive");
+    }
+
+    /// Starting a fresh session must delete any stale persisted file so a
+    /// player who quit Time Attack mid-window, came back, then started a
+    /// brand-new session begins at exactly TIME_ATTACK_DURATION_SECS.
+    #[test]
+    fn starting_new_session_deletes_stale_persisted_file() {
+        let path = tmp_ta_path("start_clears");
+        // Pre-create a stale file.
+        std::fs::write(&path, b"{\"remaining_secs\":42.0,\"wins\":99,\"saved_at_unix_secs\":0}")
+            .expect("write stale");
+
+        let mut app = headless_app();
+        app.insert_resource(TimeAttackSessionPath(Some(path.clone())));
+        // Player must be at unlock level for the start-handler to act.
+        app.world_mut().resource_mut::<ProgressResource>().0.level = CHALLENGE_UNLOCK_LEVEL;
+
+        press_t(&mut app);
+        app.update();
+
+        assert!(!path.exists(), "stale persisted file must be cleared at session start");
+
+        // And the live resource must reflect a fresh session, not the stale data.
+        let session = app.world().resource::<TimeAttackResource>();
+        assert!(session.active);
+        assert_eq!(session.wins, 0, "wins must reset to 0, not the stale 99");
+        assert!(
+            (session.remaining_secs - TIME_ATTACK_DURATION_SECS).abs() < 1.0,
+            "remaining_secs must reset to TIME_ATTACK_DURATION_SECS, not the stale 42; got {}",
+            session.remaining_secs,
+        );
+    }
+
+    /// Natural session expiry (timer reaches 0) must delete the persisted
+    /// file so the next launch does not see an "active" session that has
+    /// already ended.
+    #[test]
+    fn session_expiry_deletes_persisted_file() {
+        let path = tmp_ta_path("expiry_clears");
+        // Pre-create a file that simulates the auto-save's prior write.
+        std::fs::write(&path, b"{\"remaining_secs\":1.0,\"wins\":7,\"saved_at_unix_secs\":0}")
+            .expect("write");
+        assert!(path.exists());
+
+        let mut app = headless_app();
+        app.insert_resource(TimeAttackSessionPath(Some(path.clone())));
+        // Session about to expire on the next update tick.
+        *app.world_mut().resource_mut::<TimeAttackResource>() = TimeAttackResource {
+            active: true,
+            remaining_secs: -1.0,
+            wins: 7,
+        };
+
+        app.update();
+
+        assert!(!path.exists(), "persisted file must be deleted on natural expiry");
+        let session = app.world().resource::<TimeAttackResource>();
+        assert!(!session.active);
+    }
 }

solitaire_engine/src/win_summary_plugin.rs

@@ -314,14 +314,40 @@ pub struct ScoreBreakdown {
 }
 
 impl ScoreBreakdown {
-    /// Builds a breakdown for the given win.
+    /// Builds a breakdown for the given win, applying the player's
+    /// **cosmetic** time-bonus multiplier (`Settings::time_bonus_multiplier`)
+    /// to the raw `compute_time_bonus` result before storing it on the
+    /// breakdown.
     ///
     /// `base` is the running game score (`pending.score`); `time_seconds`,
-    /// `undo_count`, and `mode` come from the captured `WinSummaryPending`.
+    /// `undo_count`, and `mode` come from the captured `WinSummaryPending`;
-    /// All score arithmetic is saturating to keep the breakdown safe even
+    /// `time_bonus_multiplier` comes from `SettingsResource`. All score
-    /// for pathologically high scores.
+    /// arithmetic is saturating to keep the breakdown safe even for
-    pub fn compute(base: i32, time_seconds: u64, undo_count: u32, mode: GameMode) -> Self {
+    /// pathologically high scores.
-        let time_bonus = compute_time_bonus(time_seconds);
+    ///
+    /// The multiplier is **purely visual** — it changes what the player
+    /// sees in the win modal but does **not** affect achievement
+    /// thresholds, leaderboard submissions, or `StatsSnapshot` totals,
+    /// which all use the raw, unmultiplied scoring values.
+    pub fn compute(
+        base: i32,
+        time_seconds: u64,
+        undo_count: u32,
+        mode: GameMode,
+        time_bonus_multiplier: f32,
+    ) -> Self {
+        let raw_bonus = compute_time_bonus(time_seconds);
+        // Apply the cosmetic multiplier and round back to an integer so
+        // the breakdown total stays a whole-number score.
+        let scaled = (raw_bonus as f32 * time_bonus_multiplier).round();
+        // Clamp into i32 range defensively — `raw_bonus` is already
+        // bounded by `compute_time_bonus`, but a multiplier of 2.0 on
+        // an i32::MAX-adjacent bonus could still overflow the cast.
+        let time_bonus = if scaled.is_nan() {
+            0
+        } else {
+            scaled.clamp(i32::MIN as f32, i32::MAX as f32) as i32
+        };
         let no_undo_bonus = if undo_count == 0 { SCORE_NO_UNDO_BONUS } else { 0 };
         let multiplier = match mode {
             GameMode::Zen => 0.0,
@@ -554,7 +580,21 @@ fn spawn_win_summary_after_delay(
                 let anim_speed = settings
                     .as_ref()
                     .map_or(AnimSpeed::Normal, |s| s.0.animation_speed);
-                spawn_overlay(&mut commands, &pending, &session, challenge_level, anim_speed);
+                // The cosmetic time-bonus multiplier is also pulled
+                // here — defaults to 1.0 (no change) when settings are
+                // absent (tests under MinimalPlugins without
+                // SettingsPlugin).
+                let time_bonus_multiplier = settings
+                    .as_ref()
+                    .map_or(1.0_f32, |s| s.0.time_bonus_multiplier);
+                spawn_overlay(
+                    &mut commands,
+                    &pending,
+                    &session,
+                    challenge_level,
+                    anim_speed,
+                    time_bonus_multiplier,
+                );
             }
         }
     }
@@ -634,18 +674,25 @@ fn apply_screen_shake(
 /// full opacity (no stagger, no fade); otherwise rows are spawned
 /// hidden and the [`reveal_score_breakdown`] system fades them in over
 /// roughly one second.
+///
+/// `time_bonus_multiplier` is the player's cosmetic
+/// `Settings::time_bonus_multiplier` and is folded into the time-bonus
+/// row of the score breakdown only — it does **not** alter any stored
+/// score or achievement-unlock evaluation.
 fn spawn_overlay(
     commands: &mut Commands,
     pending: &WinSummaryPending,
     session: &SessionAchievements,
     challenge_level: Option<u32>,
     anim_speed: AnimSpeed,
+    time_bonus_multiplier: f32,
 ) {
     let breakdown = ScoreBreakdown::compute(
         pending.score,
         pending.time_seconds,
         pending.undo_count,
         pending.mode,
+        time_bonus_multiplier,
     );
     commands
         .spawn((
@@ -1392,7 +1439,7 @@ mod tests {
     /// the no-undo bonus fires because `undo_count == 0`.
     #[test]
     fn score_breakdown_compute_produces_expected_components() {
-        let bd = ScoreBreakdown::compute(3200, 120, 0, GameMode::Classic);
+        let bd = ScoreBreakdown::compute(3200, 120, 0, GameMode::Classic, 1.0);
         assert_eq!(bd.base, 3200);
         assert_eq!(bd.time_bonus, 5833); // 700_000 / 120
         assert_eq!(bd.no_undo_bonus, SCORE_NO_UNDO_BONUS);
@@ -1408,7 +1455,7 @@ mod tests {
     /// of the other components.
     #[test]
     fn score_breakdown_zen_mode_zeros_total() {
-        let bd = ScoreBreakdown::compute(500, 60, 0, GameMode::Zen);
+        let bd = ScoreBreakdown::compute(500, 60, 0, GameMode::Zen, 1.0);
         assert!((bd.multiplier - 0.0).abs() < f32::EPSILON);
         assert!(bd.shows_multiplier_row(), "Zen ×0 must display the multiplier row");
         assert_eq!(bd.total(), 0);
@@ -1418,7 +1465,7 @@ mod tests {
     /// row is suppressed.
     #[test]
     fn score_breakdown_skips_no_undo_row_when_undo_was_used() {
-        let bd = ScoreBreakdown::compute(100, 60, 1, GameMode::Classic);
+        let bd = ScoreBreakdown::compute(100, 60, 1, GameMode::Classic, 1.0);
         assert_eq!(bd.no_undo_bonus, 0);
         assert!(!bd.shows_no_undo_row());
     }
@@ -1427,7 +1474,7 @@ mod tests {
     /// is suppressed.
     #[test]
     fn score_breakdown_skips_time_bonus_row_when_zero() {
-        let bd = ScoreBreakdown::compute(100, 0, 0, GameMode::Classic);
+        let bd = ScoreBreakdown::compute(100, 0, 0, GameMode::Classic, 1.0);
         assert_eq!(bd.time_bonus, 0);
         assert!(!bd.shows_time_bonus_row());
     }
@@ -1438,7 +1485,7 @@ mod tests {
     /// multiplier row, ×1.0 is suppressed).
     #[test]
     fn win_modal_score_breakdown_spawns_one_row_per_component() {
-        let bd = ScoreBreakdown::compute(3200, 120, 0, GameMode::Classic);
+        let bd = ScoreBreakdown::compute(3200, 120, 0, GameMode::Classic, 1.0);
         assert_eq!(
             bd.row_count(),
             5,
@@ -1446,7 +1493,7 @@ mod tests {
         );
 
         // Zen with both bonuses ALSO shows the multiplier row.
-        let zen = ScoreBreakdown::compute(3200, 120, 0, GameMode::Zen);
+        let zen = ScoreBreakdown::compute(3200, 120, 0, GameMode::Zen, 1.0);
         assert_eq!(
             zen.row_count(),
             6,
@@ -1457,8 +1504,8 @@ mod tests {
     /// When `no_undo_bonus == 0`, the row count drops by one.
     #[test]
     fn win_modal_score_breakdown_skips_zero_bonus_rows() {
-        let bd_with = ScoreBreakdown::compute(3200, 120, 0, GameMode::Classic);
+        let bd_with = ScoreBreakdown::compute(3200, 120, 0, GameMode::Classic, 1.0);
-        let bd_without = ScoreBreakdown::compute(3200, 120, 1, GameMode::Classic);
+        let bd_without = ScoreBreakdown::compute(3200, 120, 1, GameMode::Classic, 1.0);
         assert_eq!(
             bd_with.row_count() - 1,
             bd_without.row_count(),
@@ -1466,6 +1513,52 @@ mod tests {
         );
     }
 
+    /// Cosmetic time-bonus multiplier from `Settings::time_bonus_multiplier`
+    /// scales the displayed `time_bonus` row by the factor, rounded to
+    /// the nearest integer. A `0.5` multiplier halves the canonical
+    /// `compute_time_bonus(120) = 5833` to `2917` (5833 × 0.5 = 2916.5,
+    /// round-half-to-even via `.round()` lands on 2917 in IEEE-754).
+    #[test]
+    fn score_breakdown_applies_time_bonus_multiplier() {
+        let raw = compute_time_bonus(120);
+        assert_eq!(raw, 5833, "sanity-check raw bonus before testing the multiplier");
+
+        let bd = ScoreBreakdown::compute(0, 120, 0, GameMode::Classic, 0.5);
+        let expected = ((raw as f32) * 0.5).round() as i32;
+        assert_eq!(
+            bd.time_bonus, expected,
+            "time_bonus row must reflect raw_bonus × multiplier (rounded)"
+        );
+        // The row is still shown — value is 2917, not zero.
+        assert!(bd.shows_time_bonus_row());
+    }
+
+    /// At `multiplier == 0.0` ("Off"), the time-bonus row collapses to
+    /// zero and is suppressed by the renderer (same path as a zero
+    /// elapsed time).
+    #[test]
+    fn score_breakdown_off_multiplier_zeros_time_bonus() {
+        let bd = ScoreBreakdown::compute(100, 120, 0, GameMode::Classic, 0.0);
+        assert_eq!(
+            bd.time_bonus, 0,
+            "0.0 multiplier must zero out the displayed time bonus"
+        );
+        assert!(
+            !bd.shows_time_bonus_row(),
+            "with time_bonus = 0 the row must be suppressed by the renderer"
+        );
+    }
+
+    /// A `2.0` multiplier doubles the displayed bonus — exercises the
+    /// upper end of the slider range.
+    #[test]
+    fn score_breakdown_double_multiplier_doubles_time_bonus() {
+        let raw = compute_time_bonus(120);
+        let bd = ScoreBreakdown::compute(0, 120, 0, GameMode::Classic, 2.0);
+        let expected = ((raw as f32) * 2.0).round() as i32;
+        assert_eq!(bd.time_bonus, expected);
+    }
+
     /// Pure helper test: the reveal logic uses delta-time to count
     /// down `delay_secs`; at `t = 0` only the first row is "revealed",
     /// and after one stagger interval the second row reveals as well.

solitaire_server/Cargo.toml

@@ -25,6 +25,7 @@ sqlx               = { workspace = true }
 jsonwebtoken       = { workspace = true }
 bcrypt             = { workspace = true }
 tower_governor     = { workspace = true }
+tower-http         = { version = "0.6", features = ["fs"] }
 tracing            = { workspace = true }
 tracing-subscriber = { workspace = true }
 dotenvy            = { workspace = true }

solitaire_server/migrations/002_replays.sql

@@ -0,0 +1,33 @@
+-- Migration 002: winning-replay storage
+--
+-- One row per winning replay uploaded via POST /api/replays. The replay
+-- itself is stored as the canonical JSON the desktop client wrote — it
+-- already carries a schema_version field, so the server doesn't need to
+-- shape-validate the payload beyond ensuring it parses as JSON.
+--
+-- The handful of denormalised columns (final_score, time_seconds,
+-- recorded_at) are projected out of the JSON at insert time so list
+-- endpoints (e.g. recent / per-user / leaderboard-style sorts) can be
+-- served via a covering query without touching every row's blob.
+
+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,                       -- replay's deal seed
+    draw_mode       TEXT NOT NULL,                          -- "DrawOne" | "DrawThree"
+    mode            TEXT NOT NULL,                          -- "Classic" | "Zen" | "Challenge" | "TimeAttack"
+    time_seconds    INTEGER NOT NULL,                       -- duration of the win
+    final_score     INTEGER NOT NULL,                       -- final score at the win
+    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
+);
+
+-- Recent-replays list endpoint sorts by received_at DESC; the index
+-- keeps that scan cheap on a populated table.
+CREATE INDEX IF NOT EXISTS replays_received_at_idx
+    ON replays(received_at DESC);
+
+-- Lookups by user (e.g. "my replays" view) are common too.
+CREATE INDEX IF NOT EXISTS replays_user_id_idx
+    ON replays(user_id);

solitaire_server/src/error.rs

@@ -31,6 +31,10 @@ pub enum AppError {
     #[error("bad request: {0}")]
     BadRequest(String),
 
+    /// The requested resource does not exist.
+    #[error("not found: {0}")]
+    NotFound(String),
+
     /// A database error occurred.
     #[error("database error: {0}")]
     Database(#[from] sqlx::Error),
@@ -56,6 +60,7 @@ impl IntoResponse for AppError {
             }
             AppError::UsernameTaken => (StatusCode::CONFLICT, self.to_string()),
             AppError::BadRequest(msg) => (StatusCode::BAD_REQUEST, msg.clone()),
+            AppError::NotFound(msg) => (StatusCode::NOT_FOUND, msg.clone()),
             AppError::Database(e) => {
                 tracing::error!("database error: {e}");
                 (StatusCode::INTERNAL_SERVER_ERROR, "internal server error".to_string())

solitaire_server/src/lib.rs

@@ -9,11 +9,13 @@ pub mod challenge;
 pub mod error;
 pub mod leaderboard;
 pub mod middleware;
+pub mod replays;
 pub mod sync;
 
 use axum::{
     extract::DefaultBodyLimit,
     middleware as axum_middleware,
+    response::Html,
     routing::{delete, get, post},
     Router,
 };
@@ -24,6 +26,7 @@ use tower_governor::{
     key_extractor::SmartIpKeyExtractor,
     GovernorLayer,
 };
+use tower_http::services::ServeDir;
 
 /// Shared application state injected into every Axum handler via [`axum::extract::State`].
 ///
@@ -64,6 +67,7 @@ fn build_router_inner(state: AppState, rate_limit: bool) -> Router {
     let protected = Router::new()
         .route("/api/sync/pull", get(sync::pull))
         .route("/api/sync/push", post(sync::push))
+        .route("/api/replays", post(replays::upload))
         .route("/api/leaderboard", get(leaderboard::get_leaderboard))
         .route("/api/leaderboard/opt-in", post(leaderboard::opt_in))
         .route("/api/leaderboard/opt-in", delete(leaderboard::opt_out))
@@ -98,12 +102,27 @@ fn build_router_inner(state: AppState, rate_limit: bool) -> Router {
     // Public endpoints (no auth, no rate limit beyond defaults).
     let public = Router::new()
         .route("/api/daily-challenge", get(challenge::daily_challenge))
+        .route("/api/replays/recent", get(replays::recent))
+        .route("/api/replays/{id}", get(replays::get_by_id))
         .route("/health", get(health));
 
+    // Replay web UI: a single HTML page served at `/replays/:id` plus a
+    // ServeDir for the static assets (`web/index.html`, `web/replay.css`,
+    // and the wasm-bindgen-generated `web/pkg/`). The HTML page is the
+    // same regardless of `:id` — it reads the path from `location` in JS
+    // and fetches the replay JSON from `/api/replays/:id`.
+    let web = Router::new()
+        .route(
+            "/replays/{id}",
+            get(|| async { Html(include_str!("../web/index.html")) }),
+        )
+        .nest_service("/web", ServeDir::new("solitaire_server/web"));
+
     Router::new()
         .merge(protected)
         .merge(auth_routes)
         .merge(public)
+        .merge(web)
         // Reject request bodies larger than 1 MB.
         .layer(DefaultBodyLimit::max(1024 * 1024))
         .with_state(state)

solitaire_server/src/replays.rs

@@ -0,0 +1,191 @@
+//! Winning-replay storage and retrieval.
+//!
+//! `POST /api/replays`        — upload a winning replay (auth required).
+//! `GET  /api/replays/recent` — list the N most-recent replays across users.
+//! `GET  /api/replays/:id`    — fetch a single replay's full JSON.
+//!
+//! The replay payload itself is opaque to the server — the desktop client
+//! generates a `solitaire_data::Replay` and the web playback re-executes
+//! the same atomic input list against a fresh `GameState`. The server
+//! just persists, indexes, and serves the JSON; it does not validate the
+//! semantics of the move list.
+//!
+//! Three columns are projected out of the replay JSON at insert time
+//! (`final_score`, `time_seconds`, `recorded_at`) so list endpoints can
+//! be served without scanning every blob.
+
+use axum::{
+    extract::{Path, Query, State},
+    Json,
+};
+use chrono::Utc;
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+use crate::{error::AppError, middleware::AuthenticatedUser, AppState};
+
+// ---------------------------------------------------------------------------
+// Wire types
+// ---------------------------------------------------------------------------
+
+/// Subset of `Replay` fields the server needs to project out of the
+/// uploaded JSON to populate the denormalised columns. Mirrors the
+/// fields on `solitaire_data::Replay`; we don't depend on
+/// `solitaire_data` here because the server crate must not pull in
+/// the desktop client's transitive dependencies.
+#[derive(Debug, Deserialize)]
+struct ReplayHeader {
+    seed: i64,
+    draw_mode: String,
+    mode: String,
+    time_seconds: i64,
+    final_score: i64,
+    recorded_at: String,
+}
+
+/// Successful upload acknowledgement. The server-minted `id` is what
+/// the client / web UI uses to link to `/replays/<id>`.
+#[derive(Debug, Serialize)]
+pub struct ReplayUploadResponse {
+    /// UUID v4 minted server-side at insert time.
+    pub id: String,
+}
+
+/// One row in the recent-replays list. Just the projection columns —
+/// the full move list lives behind `GET /api/replays/:id`.
+#[derive(Debug, Serialize)]
+pub struct ReplaySummary {
+    pub id: String,
+    pub username: String,
+    pub seed: i64,
+    pub draw_mode: String,
+    pub mode: String,
+    pub time_seconds: i64,
+    pub final_score: i64,
+    pub recorded_at: String,
+    pub received_at: String,
+}
+
+/// `GET /api/replays/recent?limit=N` — bound the result set so a
+/// long-tail history doesn't ship megabytes per request.
+#[derive(Debug, Deserialize)]
+pub struct RecentQuery {
+    pub limit: Option<u32>,
+}
+
+// ---------------------------------------------------------------------------
+// Handlers
+// ---------------------------------------------------------------------------
+
+/// `POST /api/replays` — accept a winning replay JSON, persist it,
+/// return the server-minted `id`. Auth required (the upload is
+/// attributed to the authenticated user).
+pub async fn upload(
+    State(state): State<AppState>,
+    user: AuthenticatedUser,
+    Json(payload): Json<serde_json::Value>,
+) -> Result<Json<ReplayUploadResponse>, AppError> {
+    // Project the header fields the SQL columns need. The full payload
+    // is stored verbatim — schema_version sits inside it and the
+    // playback path is what enforces compatibility.
+    let header: ReplayHeader = serde_json::from_value(payload.clone())
+        .map_err(|e| AppError::BadRequest(format!("replay JSON missing fields: {e}")))?;
+
+    let id = Uuid::new_v4().to_string();
+    let received_at = Utc::now().to_rfc3339();
+    let replay_json = serde_json::to_string(&payload)?;
+
+    sqlx::query!(
+        r#"INSERT INTO replays (
+              id, user_id, seed, draw_mode, mode, time_seconds, final_score,
+              recorded_at, received_at, replay_json
+           ) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"#,
+        id,
+        user.user_id,
+        header.seed,
+        header.draw_mode,
+        header.mode,
+        header.time_seconds,
+        header.final_score,
+        header.recorded_at,
+        received_at,
+        replay_json,
+    )
+    .execute(&state.pool)
+    .await?;
+
+    Ok(Json(ReplayUploadResponse { id }))
+}
+
+/// `GET /api/replays/recent` — list the N most-recent replays across
+/// every user, newest first. Auth not required so the web UI can show
+/// a public "latest wins" feed without a logged-in client.
+pub async fn recent(
+    State(state): State<AppState>,
+    Query(q): Query<RecentQuery>,
+) -> Result<Json<Vec<ReplaySummary>>, AppError> {
+    // 50 is a sane upper bound so a `?limit=999999` request can't make
+    // the server allocate megabytes. 20 is the default for a quick feed.
+    let limit = q.limit.unwrap_or(20).min(50) as i64;
+
+    let rows = sqlx::query!(
+        r#"SELECT
+              r.id              AS "id!: String",
+              u.username        AS "username!: String",
+              r.seed            AS "seed!: i64",
+              r.draw_mode       AS "draw_mode!: String",
+              r.mode            AS "mode!: String",
+              r.time_seconds    AS "time_seconds!: i64",
+              r.final_score     AS "final_score!: i64",
+              r.recorded_at     AS "recorded_at!: String",
+              r.received_at     AS "received_at!: String"
+           FROM replays r
+           JOIN users   u ON u.id = r.user_id
+           ORDER BY r.received_at DESC
+           LIMIT ?"#,
+        limit,
+    )
+    .fetch_all(&state.pool)
+    .await?;
+
+    Ok(Json(
+        rows.into_iter()
+            .map(|r| ReplaySummary {
+                id: r.id,
+                username: r.username,
+                seed: r.seed,
+                draw_mode: r.draw_mode,
+                mode: r.mode,
+                time_seconds: r.time_seconds,
+                final_score: r.final_score,
+                recorded_at: r.recorded_at,
+                received_at: r.received_at,
+            })
+            .collect(),
+    ))
+}
+
+/// `GET /api/replays/:id` — return the full replay JSON the desktop
+/// client uploaded. Public; the web UI fetches this directly.
+///
+/// The server does not validate or transform the payload — what was
+/// stored is what's returned. Schema-version compatibility is the
+/// responsibility of the playback side (web UI), matching the
+/// `schema_version` gate the desktop loader uses.
+pub async fn get_by_id(
+    State(state): State<AppState>,
+    Path(id): Path<String>,
+) -> Result<Json<serde_json::Value>, AppError> {
+    let row = sqlx::query!(
+        "SELECT replay_json FROM replays WHERE id = ?",
+        id,
+    )
+    .fetch_optional(&state.pool)
+    .await?;
+
+    let replay_json = row
+        .ok_or_else(|| AppError::NotFound("replay not found".into()))?
+        .replay_json;
+    let value: serde_json::Value = serde_json::from_str(&replay_json)?;
+    Ok(Json(value))
+}

solitaire_server/tests/server_tests.rs

@@ -1447,3 +1447,150 @@ async fn auth_rate_limit_returns_429_on_11th_request() {
         "11th request must be rate-limited with 429"
     );
 }
+
+// ---------------------------------------------------------------------------
+// Replay endpoints
+//
+// End-to-end coverage for the upload → fetch → render path that powers
+// the web replay viewer. Each test boots the full router against an
+// in-memory SQLite, registers a user, and exercises one of the three
+// replay endpoints. The schema-correctness tests (storage round-trip,
+// version gate, atomic write) live in `solitaire_data::replay`; here we
+// only verify the HTTP transport + database layer.
+// ---------------------------------------------------------------------------
+
+/// Build a minimal v2 replay JSON the upload endpoint will accept.
+///
+/// Uses the same field shape `solitaire_data::Replay` produces — kept
+/// in sync by hand because the server crate intentionally does not
+/// depend on `solitaire_data` (which carries dirs/keyring/reqwest).
+fn sample_replay_payload(seed: u64, score: i32) -> Value {
+    serde_json::json!({
+        "schema_version": 2,
+        "seed": seed,
+        "draw_mode": "DrawOne",
+        "mode": "Classic",
+        "time_seconds": 134,
+        "final_score": score,
+        "recorded_at": "2026-05-02",
+        "moves": [
+            "StockClick",
+            { "Move": { "from": "Waste", "to": { "Tableau": 3 }, "count": 1 } }
+        ]
+    })
+}
+
+/// Round-trip: register → upload → fetch → assert the payload returned
+/// by `GET /api/replays/:id` matches what was uploaded byte-for-byte.
+/// This is the canonical "the web viewer can play back what the
+/// desktop client uploaded" test.
+#[tokio::test]
+async fn replay_upload_then_fetch_round_trips_payload() {
+    let pool = test_pool().await;
+    let app = build_test_router(pool);
+    let (token, _) = register_user(app.clone(), "replay_round_trip_user", "p4ssword!").await;
+
+    let payload = sample_replay_payload(7654, 4321);
+    let resp = post_authed(app.clone(), "/api/replays", &token, payload.clone()).await;
+    assert_eq!(resp.status(), StatusCode::OK, "upload must return 200");
+    let id = body_json(resp).await["id"]
+        .as_str()
+        .expect("upload response missing `id`")
+        .to_string();
+    assert!(uuid::Uuid::parse_str(&id).is_ok(), "id must be a UUID");
+
+    // Fetch is public — no auth required, exercising the path the
+    // logged-out web viewer takes.
+    let req = Request::builder()
+        .method("GET")
+        .uri(format!("/api/replays/{id}"))
+        .header("x-forwarded-for", TEST_CLIENT_IP)
+        .body(Body::empty())
+        .expect("fetch request");
+    let resp = app.clone().oneshot(req).await.expect("oneshot");
+    assert_eq!(resp.status(), StatusCode::OK, "fetch must return 200");
+    let fetched = body_json(resp).await;
+    assert_eq!(
+        fetched, payload,
+        "fetched payload must match what was uploaded byte-for-byte",
+    );
+}
+
+/// `GET /api/replays/:id` for an id that was never uploaded must
+/// return 404 (not 500). Exercises the `AppError::NotFound` mapping
+/// added in the server commit.
+#[tokio::test]
+async fn replay_fetch_unknown_id_returns_404() {
+    let pool = test_pool().await;
+    let app = build_test_router(pool);
+    let req = Request::builder()
+        .method("GET")
+        .uri("/api/replays/nonexistent-id-1234")
+        .header("x-forwarded-for", TEST_CLIENT_IP)
+        .body(Body::empty())
+        .expect("fetch request");
+    let resp = app.oneshot(req).await.expect("oneshot");
+    assert_eq!(resp.status(), StatusCode::NOT_FOUND);
+}
+
+/// Two uploads, then `GET /api/replays/recent` — the more recent
+/// upload must come first and the response must include the
+/// uploader's username (joined from the `users` table).
+#[tokio::test]
+async fn replay_recent_lists_newest_first_with_username() {
+    let pool = test_pool().await;
+    let app = build_test_router(pool);
+    let (token, _) = register_user(app.clone(), "replay_recent_user", "p4ssword!").await;
+
+    let _ = post_authed(app.clone(), "/api/replays", &token, sample_replay_payload(1, 100)).await;
+    let _ = post_authed(app.clone(), "/api/replays", &token, sample_replay_payload(2, 200)).await;
+
+    let req = Request::builder()
+        .method("GET")
+        .uri("/api/replays/recent")
+        .header("x-forwarded-for", TEST_CLIENT_IP)
+        .body(Body::empty())
+        .expect("recent request");
+    let resp = app.oneshot(req).await.expect("oneshot");
+    assert_eq!(resp.status(), StatusCode::OK);
+
+    let entries = body_json(resp).await;
+    let array = entries.as_array().expect("recent should return an array");
+    assert!(array.len() >= 2, "two uploads should yield two list entries");
+    // Newer upload (seed = 2) must appear before older one (seed = 1).
+    let seeds: Vec<i64> = array
+        .iter()
+        .map(|e| e["seed"].as_i64().expect("seed should be an integer"))
+        .collect();
+    assert_eq!(
+        seeds, [2, 1],
+        "received_at DESC: most recent upload first",
+    );
+    assert_eq!(
+        array[0]["username"].as_str(),
+        Some("replay_recent_user"),
+        "username must be joined into the response",
+    );
+}
+
+/// `POST /api/replays` without an `Authorization` header must return
+/// 401, not silently insert as an anonymous user.
+#[tokio::test]
+async fn replay_upload_without_auth_returns_401() {
+    let pool = test_pool().await;
+    let app = build_test_router(pool);
+    let resp = post_json(app, "/api/replays", sample_replay_payload(99, 50)).await;
+    assert_eq!(resp.status(), StatusCode::UNAUTHORIZED);
+}
+
+/// `POST /api/replays` with a malformed body (missing fields the
+/// header projector needs) must return 400, not 500.
+#[tokio::test]
+async fn replay_upload_malformed_body_returns_400() {
+    let pool = test_pool().await;
+    let app = build_test_router(pool);
+    let (token, _) = register_user(app.clone(), "replay_bad_body_user", "p4ssword!").await;
+    let bad = serde_json::json!({ "schema_version": 2, "missing_required_fields": true });
+    let resp = post_authed(app, "/api/replays", &token, bad).await;
+    assert_eq!(resp.status(), StatusCode::BAD_REQUEST);
+}

solitaire_server/web/index.html

@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Solitaire Quest — Replay</title>
+    <link rel="stylesheet" href="/web/replay.css">
+</head>
+<body>
+    <header>
+        <h1>Solitaire Quest <span class="muted">— Replay</span></h1>
+        <div id="caption" class="muted">Loading…</div>
+    </header>
+
+    <main>
+        <section id="board"></section>
+
+        <section id="controls">
+            <button id="btn-prev" disabled>⏮ Restart</button>
+            <button id="btn-play">▶ Play</button>
+            <button id="btn-step">⏭ Step</button>
+            <span id="progress" class="muted">step 0 / 0</span>
+        </section>
+
+        <section id="status" class="muted">
+            <span id="score">Score 0</span>
+            <span id="moves">Moves 0</span>
+            <span id="result"></span>
+        </section>
+    </main>
+
+    <script type="module" src="/web/replay.js"></script>
+</body>
+</html>

solitaire_server/web/pkg/solitaire_wasm.js

@@ -0,0 +1,339 @@
+/**
+ * Browser-side replay state machine. Owns a live `GameState` and the
+ * replay's move list; each `step()` applies the next move.
+ */
+export class ReplayPlayer {
+    __destroy_into_raw() {
+        const ptr = this.__wbg_ptr;
+        this.__wbg_ptr = 0;
+        ReplayPlayerFinalization.unregister(this);
+        return ptr;
+    }
+    free() {
+        const ptr = this.__destroy_into_raw();
+        wasm.__wbg_replayplayer_free(ptr, 0);
+    }
+    /**
+     * Returns `true` once every move has been applied.
+     * @returns {boolean}
+     */
+    is_finished() {
+        const ret = wasm.replayplayer_is_finished(this.__wbg_ptr);
+        return ret !== 0;
+    }
+    /**
+     * Construct from a raw replay JSON string.
+     * @param {string} replay_json
+     */
+    constructor(replay_json) {
+        const ptr0 = passStringToWasm0(replay_json, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+        const len0 = WASM_VECTOR_LEN;
+        const ret = wasm.replayplayer_new(ptr0, len0);
+        if (ret[2]) {
+            throw takeFromExternrefTable0(ret[1]);
+        }
+        this.__wbg_ptr = ret[0];
+        ReplayPlayerFinalization.register(this, this.__wbg_ptr, this);
+        return this;
+    }
+    /**
+     * Snapshot the current `GameState` as a JS object (see `StateSnapshot`).
+     * @returns {any}
+     */
+    state() {
+        const ret = wasm.replayplayer_state(this.__wbg_ptr);
+        return ret;
+    }
+    /**
+     * Apply the next move; returns the post-step snapshot, or `null`
+     * once the move list is exhausted.
+     * @returns {any}
+     */
+    step() {
+        const ret = wasm.replayplayer_step(this.__wbg_ptr);
+        return ret;
+    }
+    /**
+     * 0-indexed position of the next move to apply.
+     * @returns {number}
+     */
+    step_idx() {
+        const ret = wasm.replayplayer_step_idx(this.__wbg_ptr);
+        return ret >>> 0;
+    }
+    /**
+     * Total number of moves the replay contains.
+     * @returns {number}
+     */
+    total_steps() {
+        const ret = wasm.replayplayer_total_steps(this.__wbg_ptr);
+        return ret >>> 0;
+    }
+}
+if (Symbol.dispose) ReplayPlayer.prototype[Symbol.dispose] = ReplayPlayer.prototype.free;
+function __wbg_get_imports() {
+    const import0 = {
+        __proto__: null,
+        __wbg_Error_3639a60ed15f87e7: function(arg0, arg1) {
+            const ret = Error(getStringFromWasm0(arg0, arg1));
+            return ret;
+        },
+        __wbg___wbindgen_throw_9c75d47bf9e7731e: function(arg0, arg1) {
+            throw new Error(getStringFromWasm0(arg0, arg1));
+        },
+        __wbg_error_a6fa202b58aa1cd3: function(arg0, arg1) {
+            let deferred0_0;
+            let deferred0_1;
+            try {
+                deferred0_0 = arg0;
+                deferred0_1 = arg1;
+                console.error(getStringFromWasm0(arg0, arg1));
+            } finally {
+                wasm.__wbindgen_free(deferred0_0, deferred0_1, 1);
+            }
+        },
+        __wbg_new_227d7c05414eb861: function() {
+            const ret = new Error();
+            return ret;
+        },
+        __wbg_new_2fad8ca02fd00684: function() {
+            const ret = new Object();
+            return ret;
+        },
+        __wbg_new_3baa8d9866155c79: function() {
+            const ret = new Array();
+            return ret;
+        },
+        __wbg_set_6be42768c690e380: function(arg0, arg1, arg2) {
+            arg0[arg1] = arg2;
+        },
+        __wbg_set_f614f6a0608d1d1d: function(arg0, arg1, arg2) {
+            arg0[arg1 >>> 0] = arg2;
+        },
+        __wbg_stack_3b0d974bbf31e44f: function(arg0, arg1) {
+            const ret = arg1.stack;
+            const ptr1 = passStringToWasm0(ret, wasm.__wbindgen_malloc, wasm.__wbindgen_realloc);
+            const len1 = WASM_VECTOR_LEN;
+            getDataViewMemory0().setInt32(arg0 + 4 * 1, len1, true);
+            getDataViewMemory0().setInt32(arg0 + 4 * 0, ptr1, true);
+        },
+        __wbindgen_cast_0000000000000001: function(arg0) {
+            // Cast intrinsic for `F64 -> Externref`.
+            const ret = arg0;
+            return ret;
+        },
+        __wbindgen_cast_0000000000000002: function(arg0, arg1) {
+            // Cast intrinsic for `Ref(String) -> Externref`.
+            const ret = getStringFromWasm0(arg0, arg1);
+            return ret;
+        },
+        __wbindgen_cast_0000000000000003: function(arg0) {
+            // Cast intrinsic for `U64 -> Externref`.
+            const ret = BigInt.asUintN(64, arg0);
+            return ret;
+        },
+        __wbindgen_init_externref_table: function() {
+            const table = wasm.__wbindgen_externrefs;
+            const offset = table.grow(4);
+            table.set(0, undefined);
+            table.set(offset + 0, undefined);
+            table.set(offset + 1, null);
+            table.set(offset + 2, true);
+            table.set(offset + 3, false);
+        },
+    };
+    return {
+        __proto__: null,
+        "./solitaire_wasm_bg.js": import0,
+    };
+}
+
+const ReplayPlayerFinalization = (typeof FinalizationRegistry === 'undefined')
+    ? { register: () => {}, unregister: () => {} }
+    : new FinalizationRegistry(ptr => wasm.__wbg_replayplayer_free(ptr, 1));
+
+let cachedDataViewMemory0 = null;
+function getDataViewMemory0() {
+    if (cachedDataViewMemory0 === null || cachedDataViewMemory0.buffer.detached === true || (cachedDataViewMemory0.buffer.detached === undefined && cachedDataViewMemory0.buffer !== wasm.memory.buffer)) {
+        cachedDataViewMemory0 = new DataView(wasm.memory.buffer);
+    }
+    return cachedDataViewMemory0;
+}
+
+function getStringFromWasm0(ptr, len) {
+    return decodeText(ptr >>> 0, len);
+}
+
+let cachedUint8ArrayMemory0 = null;
+function getUint8ArrayMemory0() {
+    if (cachedUint8ArrayMemory0 === null || cachedUint8ArrayMemory0.byteLength === 0) {
+        cachedUint8ArrayMemory0 = new Uint8Array(wasm.memory.buffer);
+    }
+    return cachedUint8ArrayMemory0;
+}
+
+function passStringToWasm0(arg, malloc, realloc) {
+    if (realloc === undefined) {
+        const buf = cachedTextEncoder.encode(arg);
+        const ptr = malloc(buf.length, 1) >>> 0;
+        getUint8ArrayMemory0().subarray(ptr, ptr + buf.length).set(buf);
+        WASM_VECTOR_LEN = buf.length;
+        return ptr;
+    }
+
+    let len = arg.length;
+    let ptr = malloc(len, 1) >>> 0;
+
+    const mem = getUint8ArrayMemory0();
+
+    let offset = 0;
+
+    for (; offset < len; offset++) {
+        const code = arg.charCodeAt(offset);
+        if (code > 0x7F) break;
+        mem[ptr + offset] = code;
+    }
+    if (offset !== len) {
+        if (offset !== 0) {
+            arg = arg.slice(offset);
+        }
+        ptr = realloc(ptr, len, len = offset + arg.length * 3, 1) >>> 0;
+        const view = getUint8ArrayMemory0().subarray(ptr + offset, ptr + len);
+        const ret = cachedTextEncoder.encodeInto(arg, view);
+
+        offset += ret.written;
+        ptr = realloc(ptr, len, offset, 1) >>> 0;
+    }
+
+    WASM_VECTOR_LEN = offset;
+    return ptr;
+}
+
+function takeFromExternrefTable0(idx) {
+    const value = wasm.__wbindgen_externrefs.get(idx);
+    wasm.__externref_table_dealloc(idx);
+    return value;
+}
+
+let cachedTextDecoder = new TextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+cachedTextDecoder.decode();
+const MAX_SAFARI_DECODE_BYTES = 2146435072;
+let numBytesDecoded = 0;
+function decodeText(ptr, len) {
+    numBytesDecoded += len;
+    if (numBytesDecoded >= MAX_SAFARI_DECODE_BYTES) {
+        cachedTextDecoder = new TextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+        cachedTextDecoder.decode();
+        numBytesDecoded = len;
+    }
+    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+}
+
+const cachedTextEncoder = new TextEncoder();
+
+if (!('encodeInto' in cachedTextEncoder)) {
+    cachedTextEncoder.encodeInto = function (arg, view) {
+        const buf = cachedTextEncoder.encode(arg);
+        view.set(buf);
+        return {
+            read: arg.length,
+            written: buf.length
+        };
+    };
+}
+
+let WASM_VECTOR_LEN = 0;
+
+let wasmModule, wasmInstance, wasm;
+function __wbg_finalize_init(instance, module) {
+    wasmInstance = instance;
+    wasm = instance.exports;
+    wasmModule = module;
+    cachedDataViewMemory0 = null;
+    cachedUint8ArrayMemory0 = null;
+    wasm.__wbindgen_start();
+    return wasm;
+}
+
+async function __wbg_load(module, imports) {
+    if (typeof Response === 'function' && module instanceof Response) {
+        if (typeof WebAssembly.instantiateStreaming === 'function') {
+            try {
+                return await WebAssembly.instantiateStreaming(module, imports);
+            } catch (e) {
+                const validResponse = module.ok && expectedResponseType(module.type);
+
+                if (validResponse && module.headers.get('Content-Type') !== 'application/wasm') {
+                    console.warn("`WebAssembly.instantiateStreaming` failed because your server does not serve Wasm with `application/wasm` MIME type. Falling back to `WebAssembly.instantiate` which is slower. Original error:\n", e);
+
+                } else { throw e; }
+            }
+        }
+
+        const bytes = await module.arrayBuffer();
+        return await WebAssembly.instantiate(bytes, imports);
+    } else {
+        const instance = await WebAssembly.instantiate(module, imports);
+
+        if (instance instanceof WebAssembly.Instance) {
+            return { instance, module };
+        } else {
+            return instance;
+        }
+    }
+
+    function expectedResponseType(type) {
+        switch (type) {
+            case 'basic': case 'cors': case 'default': return true;
+        }
+        return false;
+    }
+}
+
+function initSync(module) {
+    if (wasm !== undefined) return wasm;
+
+
+    if (module !== undefined) {
+        if (Object.getPrototypeOf(module) === Object.prototype) {
+            ({module} = module)
+        } else {
+            console.warn('using deprecated parameters for `initSync()`; pass a single object instead')
+        }
+    }
+
+    const imports = __wbg_get_imports();
+    if (!(module instanceof WebAssembly.Module)) {
+        module = new WebAssembly.Module(module);
+    }
+    const instance = new WebAssembly.Instance(module, imports);
+    return __wbg_finalize_init(instance, module);
+}
+
+async function __wbg_init(module_or_path) {
+    if (wasm !== undefined) return wasm;
+
+
+    if (module_or_path !== undefined) {
+        if (Object.getPrototypeOf(module_or_path) === Object.prototype) {
+            ({module_or_path} = module_or_path)
+        } else {
+            console.warn('using deprecated parameters for the initialization function; pass a single object instead')
+        }
+    }
+
+    if (module_or_path === undefined) {
+        module_or_path = new URL('solitaire_wasm_bg.wasm', import.meta.url);
+    }
+    const imports = __wbg_get_imports();
+
+    if (typeof module_or_path === 'string' || (typeof Request === 'function' && module_or_path instanceof Request) || (typeof URL === 'function' && module_or_path instanceof URL)) {
+        module_or_path = fetch(module_or_path);
+    }
+
+    const { instance, module } = await __wbg_load(await module_or_path, imports);
+
+    return __wbg_finalize_init(instance, module);
+}
+
+export { initSync, __wbg_init as default };

solitaire_server/web/replay.css

@@ -0,0 +1,183 @@
+/* Solitaire Quest replay viewer — palette mirrors the desktop client's
+   midnight-purple Balatro tone (BG_BASE = #1A0F2E) and the dark felt
+   from the engine's TABLE_COLOUR. */
+
+:root {
+    --bg: #0f0a1f;
+    --felt: #0f4c30;
+    --panel: #1a0f2e;
+    --panel-hi: #2d1b69;
+    --text: #f5f0ff;
+    --text-muted: #b5a8d5;
+    --accent: #ffd23f;
+    --red: #cc3344;
+    --black: #1a0f2e;
+    --card-bg: #ffffff;
+    --card-border: #ccc;
+    --card-w: 80px;
+    --card-h: 112px;
+    --gap: 12px;
+}
+
+* { box-sizing: border-box; }
+
+body {
+    margin: 0;
+    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
+    background: var(--bg);
+    color: var(--text);
+    min-height: 100vh;
+    display: flex;
+    flex-direction: column;
+}
+
+header {
+    padding: 16px 24px;
+    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
+    display: flex;
+    flex-direction: column;
+    gap: 4px;
+}
+
+h1 {
+    margin: 0;
+    font-size: 20px;
+    font-weight: 600;
+}
+
+.muted { color: var(--text-muted); }
+
+main {
+    flex: 1;
+    display: flex;
+    flex-direction: column;
+    gap: 16px;
+    padding: 24px;
+    align-items: center;
+}
+
+/* Board: a positioning context for both the dashed empty-pile slots
+   and the absolutely-positioned card sprites. Width matches the
+   7-column grid (7*card-w + 6 inter-column gaps), height covers the
+   top row plus a worst-case 13-card tableau fan. Cards live as
+   siblings of the slot placeholders so they can move between piles
+   without ever changing parent — the transform-based `transition`
+   then animates the flight. */
+#board {
+    position: relative;
+    background: var(--felt);
+    border-radius: 12px;
+    padding: 24px;
+    width: calc(7 * var(--card-w) + 6 * var(--gap));
+    /* Top row + a generous fan budget (12 fan steps + the card's
+       own height) so a king-down-to-ace column never overflows. */
+    height: calc(var(--card-h) + 32px + var(--card-h) + 12 * 28px);
+}
+
+/* Empty-pile slot placeholders are absolutely positioned at the same
+   coordinates the renderer uses for cards, so they line up perfectly
+   when the pile is empty. */
+.slot {
+    position: absolute;
+    width: var(--card-w);
+    height: var(--card-h);
+    border: 2px dashed rgba(255, 255, 255, 0.15);
+    border-radius: 8px;
+}
+
+.card {
+    position: absolute;
+    /* `top: 0; left: 0` plus a per-card `transform: translate(...)`
+       gives us a single transformed property to animate. Using
+       `transform` (rather than `top` / `left`) lets the browser run
+       the animation on the compositor — smooth even on the
+       low-spec laptops the player tests on. */
+    top: 0;
+    left: 0;
+    width: var(--card-w);
+    height: var(--card-h);
+    background: var(--card-bg);
+    border: 1px solid var(--card-border);
+    border-radius: 6px;
+    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
+    padding: 4px 6px;
+    font-family: "Helvetica Neue", Arial, sans-serif;
+    font-weight: 600;
+    line-height: 1;
+    user-select: none;
+    transition: transform 280ms cubic-bezier(0.22, 1, 0.36, 1),
+        opacity 200ms ease;
+    will-change: transform;
+}
+
+.card.face-down {
+    background:
+        repeating-linear-gradient(
+            45deg,
+            #482f97 0,
+            #482f97 6px,
+            #2d1b69 6px,
+            #2d1b69 12px
+        );
+    color: transparent;
+    border-color: #4a3a8a;
+}
+
+.card .corner {
+    position: absolute;
+    font-size: 14px;
+    line-height: 1.1;
+    text-align: center;
+}
+
+.card .corner.top { top: 4px; left: 6px; }
+.card .corner.bottom { bottom: 4px; right: 6px; transform: rotate(180deg); }
+
+.card.red { color: var(--red); }
+.card.black { color: var(--black); }
+
+.card .center {
+    position: absolute;
+    top: 50%;
+    left: 50%;
+    transform: translate(-50%, -50%);
+    font-size: 28px;
+}
+
+#controls {
+    display: flex;
+    gap: 12px;
+    align-items: center;
+}
+
+#controls button {
+    background: var(--panel-hi);
+    color: var(--text);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+    border-radius: 6px;
+    padding: 8px 16px;
+    cursor: pointer;
+    font-size: 14px;
+    font-family: inherit;
+}
+
+#controls button:hover:not(:disabled) {
+    background: var(--accent);
+    color: var(--black);
+}
+
+#controls button:disabled {
+    opacity: 0.5;
+    cursor: default;
+}
+
+#status {
+    display: flex;
+    gap: 24px;
+    font-size: 14px;
+}
+
+#status #result.win {
+    color: var(--accent);
+    font-weight: 600;
+}

solitaire_server/web/replay.js

@@ -0,0 +1,316 @@
+// Solitaire Quest replay viewer.
+//
+// Pulls the replay JSON from `/api/replays/:id`, hands it to the
+// `solitaire_wasm` ReplayPlayer (which owns a real solitaire_core
+// `GameState` compiled to WebAssembly), and renders each step's pile
+// snapshot as plain HTML cards. The WASM module is the single source
+// of truth for the rules engine — we don't re-implement Klondike in JS.
+//
+// Card flight animation: each card's DOM element persists across
+// re-renders, keyed by `card.id`. `render()` updates each card's
+// `transform: translate(...)` to its new (pile, index) coordinates;
+// the CSS `transition` on `transform` animates the flight. Cards that
+// disappear from the snapshot fade and remove; new cards fade in at
+// their target position.
+
+import init, { ReplayPlayer } from "/web/pkg/solitaire_wasm.js";
+
+const STEP_INTERVAL_MS = 600;
+const FAN_OFFSET_PX = 28;
+const CARD_W = 80;
+const CARD_H = 112;
+const GAP = 12;
+
+// Pile origin (top-left of the slot, in board-relative pixels).
+// Top row: stock at column 0, waste at column 1, foundations at 3-6.
+// Bottom row: tableau columns 0-6.
+const TOP_ROW_Y = 0;
+const TABLEAU_ROW_Y = CARD_H + 32;
+const colX = (col) => col * (CARD_W + GAP);
+
+const PILE_ORIGIN = {
+    stock: { x: colX(0), y: TOP_ROW_Y },
+    waste: { x: colX(1), y: TOP_ROW_Y },
+    "foundation-0": { x: colX(3), y: TOP_ROW_Y },
+    "foundation-1": { x: colX(4), y: TOP_ROW_Y },
+    "foundation-2": { x: colX(5), y: TOP_ROW_Y },
+    "foundation-3": { x: colX(6), y: TOP_ROW_Y },
+    "tableau-0": { x: colX(0), y: TABLEAU_ROW_Y },
+    "tableau-1": { x: colX(1), y: TABLEAU_ROW_Y },
+    "tableau-2": { x: colX(2), y: TABLEAU_ROW_Y },
+    "tableau-3": { x: colX(3), y: TABLEAU_ROW_Y },
+    "tableau-4": { x: colX(4), y: TABLEAU_ROW_Y },
+    "tableau-5": { x: colX(5), y: TABLEAU_ROW_Y },
+    "tableau-6": { x: colX(6), y: TABLEAU_ROW_Y },
+};
+
+const SUIT_GLYPHS = {
+    clubs: "♣",
+    diamonds: "♦",
+    hearts: "♥",
+    spades: "♠",
+};
+const RED_SUITS = new Set(["diamonds", "hearts"]);
+const RANK_LABELS = ["", "A", "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K"];
+
+const board = document.getElementById("board");
+const captionEl = document.getElementById("caption");
+const progressEl = document.getElementById("progress");
+const scoreEl = document.getElementById("score");
+const movesEl = document.getElementById("moves");
+const resultEl = document.getElementById("result");
+const btnPlay = document.getElementById("btn-play");
+const btnStep = document.getElementById("btn-step");
+const btnPrev = document.getElementById("btn-prev");
+
+let player = null;
+let replayJson = null;
+let playInterval = null;
+
+// Persistent map: card.id → DOM element. Reused across renders so the
+// browser interpolates the `transform` change rather than rebuilding
+// nodes every step.
+const cardEls = new Map();
+
+async function bootstrap() {
+    const id = window.location.pathname.split("/").pop();
+    if (!id) {
+        captionEl.textContent = "No replay id in URL.";
+        return;
+    }
+
+    let response;
+    try {
+        response = await fetch(`/api/replays/${id}`);
+    } catch (e) {
+        captionEl.textContent = `Network error: ${e}`;
+        return;
+    }
+    if (!response.ok) {
+        captionEl.textContent = `Server returned ${response.status}.`;
+        return;
+    }
+    const replay = await response.json();
+    replayJson = JSON.stringify(replay);
+
+    captionEl.textContent =
+        `Seed ${replay.seed} · ${replay.draw_mode} · ${replay.mode} ` +
+        `· ${formatDuration(replay.time_seconds)} win on ${replay.recorded_at} ` +
+        `· final score ${replay.final_score}`;
+
+    spawnEmptySlots();
+    await init();
+    resetPlayer();
+}
+
+/// Spawn the dashed empty-pile placeholders once. They never move and
+/// never get keyed to card ids, so they're outside the cardEls map.
+function spawnEmptySlots() {
+    Object.entries(PILE_ORIGIN).forEach(([name, { x, y }]) => {
+        const slot = document.createElement("div");
+        slot.className = `slot slot-${name}`;
+        slot.style.transform = `translate(${x}px, ${y}px)`;
+        board.appendChild(slot);
+    });
+}
+
+function resetPlayer() {
+    if (playInterval) {
+        clearInterval(playInterval);
+        playInterval = null;
+        btnPlay.textContent = "▶ Play";
+    }
+    player = new ReplayPlayer(replayJson);
+    btnPrev.disabled = true;
+    btnStep.disabled = false;
+    btnPlay.disabled = false;
+    render(player.state());
+}
+
+function step() {
+    const snap = player.step();
+    if (snap === null) {
+        finish();
+        return null;
+    }
+    btnPrev.disabled = false;
+    render(snap);
+    return snap;
+}
+
+function finish() {
+    if (playInterval) {
+        clearInterval(playInterval);
+        playInterval = null;
+    }
+    btnPlay.textContent = "▶ Play";
+    btnPlay.disabled = true;
+    btnStep.disabled = true;
+}
+
+/// Apply `snap` to the persistent card-element map.
+///
+/// Phase 1: collect every card present in this snapshot, computing its
+/// target board-relative (x, y) from its pile + index.
+/// Phase 2: for each card, find or create its DOM element and update
+/// its visual state + transform. Persistent elements interpolate via
+/// CSS transition; freshly-created ones fade in.
+/// Phase 3: any card present in `cardEls` but absent from `snap` (rare
+/// but happens during stat resets) fades out and is removed.
+function render(snap) {
+    if (!snap) return;
+
+    const targets = new Map(); // card.id → { card, x, y }
+
+    function placePile(name, cards, fan) {
+        const origin = PILE_ORIGIN[name];
+        cards.forEach((card, idx) => {
+            const yOffset = fan ? idx * FAN_OFFSET_PX : 0;
+            targets.set(card.id, {
+                card,
+                x: origin.x,
+                y: origin.y + yOffset,
+                z: idx,
+            });
+        });
+    }
+
+    placePile("stock", snap.stock, false);
+    placePile("waste", snap.waste, false);
+    snap.foundations.forEach((cards, idx) =>
+        placePile(`foundation-${idx}`, cards, false));
+    snap.tableaus.forEach((cards, idx) =>
+        placePile(`tableau-${idx}`, cards, true));
+
+    // Apply or create.
+    targets.forEach(({ card, x, y, z }) => {
+        let el = cardEls.get(card.id);
+        if (!el) {
+            el = createCardElement(card);
+            // Spawn off-screen with opacity 0 so the entry transition
+            // fades in at the destination rather than popping.
+            el.style.transform = `translate(${x}px, ${y}px)`;
+            el.style.opacity = "0";
+            board.appendChild(el);
+            cardEls.set(card.id, el);
+            // Force the browser to commit the off-screen frame before
+            // we set the visible state, so the transition runs.
+            requestAnimationFrame(() => {
+                el.style.opacity = "1";
+            });
+        } else {
+            updateCardElement(el, card);
+            el.style.transform = `translate(${x}px, ${y}px)`;
+        }
+        el.style.zIndex = String(z + 1);
+    });
+
+    // Drop any cards no longer in play (e.g. on player reset).
+    cardEls.forEach((el, id) => {
+        if (!targets.has(id)) {
+            el.style.opacity = "0";
+            // Remove after the fade transition completes.
+            setTimeout(() => {
+                el.remove();
+                cardEls.delete(id);
+            }, 220);
+        }
+    });
+
+    progressEl.textContent = `step ${snap.step_idx} / ${snap.total_steps}`;
+    scoreEl.textContent = `Score ${snap.score}`;
+    movesEl.textContent = `Moves ${snap.move_count}`;
+    if (snap.is_won) {
+        resultEl.textContent = "✨ Won";
+        resultEl.classList.add("win");
+    } else {
+        resultEl.textContent = "";
+        resultEl.classList.remove("win");
+    }
+}
+
+function createCardElement(card) {
+    const el = document.createElement("div");
+    el.className = "card";
+    el.dataset.cardId = String(card.id);
+    populateCardFace(el, card);
+    return el;
+}
+
+/// Cheap "is this still the same visual state" check. Face-up cards
+/// only need a re-paint if their face_up flag flipped (rank/suit are
+/// immutable per id), so we can skip rebuilding the inner DOM for the
+/// 99% case where only the transform changed.
+function updateCardElement(el, card) {
+    const wasFaceDown = el.classList.contains("face-down");
+    const isFaceDown = !card.face_up;
+    if (wasFaceDown !== isFaceDown) {
+        el.replaceChildren();
+        el.classList.remove("red", "black", "face-down");
+        populateCardFace(el, card);
+    }
+}
+
+function populateCardFace(el, card) {
+    if (!card.face_up) {
+        el.classList.add("face-down");
+        return;
+    }
+    el.classList.add(RED_SUITS.has(card.suit) ? "red" : "black");
+    const label = RANK_LABELS[card.rank] || "?";
+    const glyph = SUIT_GLYPHS[card.suit] || "?";
+
+    const top = document.createElement("span");
+    top.className = "corner top";
+    top.textContent = `${label}\n${glyph}`;
+    el.appendChild(top);
+
+    const center = document.createElement("span");
+    center.className = "center";
+    center.textContent = glyph;
+    el.appendChild(center);
+
+    const bottom = document.createElement("span");
+    bottom.className = "corner bottom";
+    bottom.textContent = `${label}\n${glyph}`;
+    el.appendChild(bottom);
+}
+
+function formatDuration(seconds) {
+    const m = Math.floor(seconds / 60);
+    const s = seconds % 60;
+    return `${m}:${String(s).padStart(2, "0")}`;
+}
+
+btnStep.addEventListener("click", () => {
+    if (player) step();
+});
+
+btnPlay.addEventListener("click", () => {
+    if (!player) return;
+    if (playInterval) {
+        clearInterval(playInterval);
+        playInterval = null;
+        btnPlay.textContent = "▶ Play";
+        return;
+    }
+    btnPlay.textContent = "⏸ Pause";
+    playInterval = setInterval(() => {
+        const snap = step();
+        if (snap === null) finish();
+    }, STEP_INTERVAL_MS);
+});
+
+btnPrev.addEventListener("click", () => {
+    if (!replayJson) return;
+    // Drop every existing card so the next render fades them all in
+    // at the freshly-dealt positions. Without this, cards from the
+    // current state would slide to wherever the new deal puts them
+    // — confusing since the deal is supposed to look like a fresh
+    // start, not a continuation.
+    cardEls.forEach((el) => el.remove());
+    cardEls.clear();
+    resetPlayer();
+});
+
+bootstrap();

solitaire_sync/src/merge.rs

@@ -3,10 +3,10 @@
 //! All functions are free of I/O and side effects — safe to call from any
 //! context including unit tests and the Bevy main thread.
 
-use chrono::Utc;
+use chrono::{NaiveDate, Utc};
 
 use crate::{AchievementRecord, ConflictReport, PlayerProgress, StatsSnapshot, SyncPayload};
-use crate::progress::level_for_xp;
+use crate::progress::{level_for_xp, DAILY_CHALLENGE_HISTORY_CAP};
 
 /// Merge two [`SyncPayload`]s into a single authoritative result.
 ///
@@ -109,10 +109,45 @@ fn merge_stats(
         best_single_score: local.best_single_score.max(remote.best_single_score),
         draw_one_wins: local.draw_one_wins.max(remote.draw_one_wins),
         draw_three_wins: local.draw_three_wins.max(remote.draw_three_wins),
+        // Per-mode bests. Bests take max; fastest times take a *zero-aware*
+        // min — see [`min_ignore_zero`] for the rationale (0 means "no win
+        // yet" for these fields, unlike the lifetime `fastest_win_seconds`
+        // which uses `u64::MAX` as its sentinel).
+        classic_best_score: local.classic_best_score.max(remote.classic_best_score),
+        classic_fastest_win_seconds: min_ignore_zero(
+            local.classic_fastest_win_seconds,
+            remote.classic_fastest_win_seconds,
+        ),
+        zen_best_score: local.zen_best_score.max(remote.zen_best_score),
+        zen_fastest_win_seconds: min_ignore_zero(
+            local.zen_fastest_win_seconds,
+            remote.zen_fastest_win_seconds,
+        ),
+        challenge_best_score: local.challenge_best_score.max(remote.challenge_best_score),
+        challenge_fastest_win_seconds: min_ignore_zero(
+            local.challenge_fastest_win_seconds,
+            remote.challenge_fastest_win_seconds,
+        ),
         last_modified: Utc::now(),
     }
 }
 
+/// Zero-aware minimum: returns the smaller of `a` and `b`, but treats `0` as
+/// "no value recorded yet" so `min_ignore_zero(0, x) == x`.
+///
+/// The lifetime `fastest_win_seconds` field uses `u64::MAX` as its "no wins"
+/// sentinel (see [`StatsSnapshot::default`]) and so a plain `min` works for
+/// it. The per-mode `*_fastest_win_seconds` fields, on the other hand, are
+/// `#[serde(default)]` — and `u64`'s default is 0, not `u64::MAX`. Using a
+/// straight `min` would therefore wrongly resolve "one side has a real time,
+/// the other has no win" to 0. This helper preserves the real time instead.
+fn min_ignore_zero(a: u64, b: u64) -> u64 {
+    match (a, b) {
+        (0, x) | (x, 0) => x,
+        _ => a.min(b),
+    }
+}
+
 // ---------------------------------------------------------------------------
 // Achievements
 // ---------------------------------------------------------------------------
@@ -240,6 +275,22 @@ fn merge_progress(
     // Challenge index: take the higher (further ahead in challenge progression).
     let challenge_index = local.challenge_index.max(remote.challenge_index);
 
+    // Daily-challenge history: union the two ordered lists into a sorted,
+    // deduplicated, capped Vec so completions made on either device survive.
+    let daily_challenge_history = union_naive_dates(
+        &local.daily_challenge_history,
+        &remote.daily_challenge_history,
+    );
+
+    // Longest streak ever: simple max — never regresses.
+    let daily_challenge_longest_streak = local
+        .daily_challenge_longest_streak
+        .max(remote.daily_challenge_longest_streak)
+        // Also defend against an old payload whose `longest_streak` was
+        // never written but whose current `daily_challenge_streak` exceeds
+        // the recorded longest — keep them coherent post-merge.
+        .max(daily_challenge_streak);
+
     PlayerProgress {
         total_xp,
         level: level_for_xp(total_xp),
@@ -250,6 +301,8 @@ fn merge_progress(
         unlocked_card_backs,
         unlocked_backgrounds,
         challenge_index,
+        daily_challenge_history,
+        daily_challenge_longest_streak,
         last_modified: Utc::now(),
     }
 }
@@ -261,6 +314,20 @@ fn union_usize_vecs(a: &[usize], b: &[usize]) -> Vec<usize> {
     set.into_iter().collect()
 }
 
+/// Returns the sorted union of two `NaiveDate` slices with duplicates
+/// removed and the result capped at [`DAILY_CHALLENGE_HISTORY_CAP`]
+/// entries (oldest dates trimmed first).
+fn union_naive_dates(a: &[NaiveDate], b: &[NaiveDate]) -> Vec<NaiveDate> {
+    use std::collections::BTreeSet;
+    let set: BTreeSet<NaiveDate> = a.iter().chain(b.iter()).copied().collect();
+    let mut v: Vec<NaiveDate> = set.into_iter().collect();
+    if v.len() > DAILY_CHALLENGE_HISTORY_CAP {
+        let excess = v.len() - DAILY_CHALLENGE_HISTORY_CAP;
+        v.drain(0..excess);
+    }
+    v
+}
+
 // ---------------------------------------------------------------------------
 // Tests
 // ---------------------------------------------------------------------------
@@ -753,4 +820,191 @@ mod tests {
         let (merged, _) = merge(&local, &remote);
         assert_eq!(merged.stats.fastest_win_seconds, 300);
     }
+
+    // -----------------------------------------------------------------------
+    // Daily-challenge history + longest-streak merge
+    // -----------------------------------------------------------------------
+
+    fn nd(y: i32, m: u32, d: u32) -> NaiveDate {
+        NaiveDate::from_ymd_opt(y, m, d).unwrap()
+    }
+
+    #[test]
+    fn merge_unions_daily_challenge_history() {
+        // Local and remote have disjoint completion dates; the merged
+        // history must contain all of them, sorted ascending, with no
+        // duplicates and within the cap.
+        let mut local = default_payload();
+        local.progress.daily_challenge_history =
+            vec![nd(2026, 4, 20), nd(2026, 4, 22), nd(2026, 4, 24)];
+        let mut remote = default_payload();
+        remote.progress.daily_challenge_history =
+            vec![nd(2026, 4, 21), nd(2026, 4, 22), nd(2026, 4, 25)];
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(
+            merged.progress.daily_challenge_history,
+            vec![
+                nd(2026, 4, 20),
+                nd(2026, 4, 21),
+                nd(2026, 4, 22),
+                nd(2026, 4, 24),
+                nd(2026, 4, 25),
+            ],
+            "history union must be sorted, deduplicated, and contain every date from either side"
+        );
+        assert!(
+            merged.progress.daily_challenge_history.len() <= DAILY_CHALLENGE_HISTORY_CAP,
+            "merged history must respect the 365-entry cap"
+        );
+    }
+
+    #[test]
+    fn merge_caps_daily_challenge_history_at_max() {
+        // Construct a local history that already has CAP entries and a
+        // remote history that adds 50 fresher entries — the merge must
+        // drop the oldest 50 so the cap is preserved.
+        let start = nd(2024, 1, 1);
+        let local_dates: Vec<NaiveDate> = (0..DAILY_CHALLENGE_HISTORY_CAP as i64)
+            .map(|i| start + chrono::Duration::days(i))
+            .collect();
+        let remote_dates: Vec<NaiveDate> = (DAILY_CHALLENGE_HISTORY_CAP as i64
+            ..DAILY_CHALLENGE_HISTORY_CAP as i64 + 50)
+            .map(|i| start + chrono::Duration::days(i))
+            .collect();
+
+        let mut local = default_payload();
+        local.progress.daily_challenge_history = local_dates.clone();
+        let mut remote = default_payload();
+        remote.progress.daily_challenge_history = remote_dates.clone();
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(
+            merged.progress.daily_challenge_history.len(),
+            DAILY_CHALLENGE_HISTORY_CAP,
+            "merged history must be capped at DAILY_CHALLENGE_HISTORY_CAP"
+        );
+        // The oldest 50 entries should have been evicted; oldest retained
+        // is therefore start + 50 days.
+        assert_eq!(
+            merged.progress.daily_challenge_history.first().copied(),
+            Some(start + chrono::Duration::days(50))
+        );
+        // Most recent retained is the last remote date.
+        assert_eq!(
+            merged.progress.daily_challenge_history.last().copied(),
+            remote_dates.last().copied()
+        );
+    }
+
+    #[test]
+    fn merge_takes_max_longest_streak() {
+        let mut local = default_payload();
+        local.progress.daily_challenge_longest_streak = 4;
+        let mut remote = default_payload();
+        remote.progress.daily_challenge_longest_streak = 9;
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(
+            merged.progress.daily_challenge_longest_streak, 9,
+            "longest streak must be the max across both sides"
+        );
+    }
+
+    // -----------------------------------------------------------------------
+    // Per-mode bests merge
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn merge_per_mode_best_takes_max() {
+        // Classic best score: 1000 vs 2000 → 2000. Mirror behaviour for
+        // `best_single_score` so per-mode follows the same rule.
+        let mut local = default_payload();
+        local.stats.classic_best_score = 1000;
+        let mut remote = default_payload();
+        remote.stats.classic_best_score = 2000;
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(merged.stats.classic_best_score, 2000);
+    }
+
+    #[test]
+    fn merge_per_mode_best_takes_max_for_zen_and_challenge() {
+        let mut local = default_payload();
+        local.stats.zen_best_score = 800;
+        local.stats.challenge_best_score = 5000;
+        let mut remote = default_payload();
+        remote.stats.zen_best_score = 1500;
+        remote.stats.challenge_best_score = 3000;
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(merged.stats.zen_best_score, 1500);
+        assert_eq!(merged.stats.challenge_best_score, 5000);
+    }
+
+    #[test]
+    fn merge_per_mode_fastest_ignores_zero() {
+        // Local has no Zen win (zen_fastest = 0); remote has 180s.
+        // Straight min(0, 180) would return 0 — wrong. The merge must
+        // preserve the real time.
+        let local = default_payload();
+        let mut remote = default_payload();
+        remote.stats.zen_fastest_win_seconds = 180;
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(merged.stats.zen_fastest_win_seconds, 180);
+    }
+
+    #[test]
+    fn merge_per_mode_fastest_takes_min_when_both_present() {
+        // When both sides have real times, the merge takes the smaller —
+        // mirroring the lifetime `fastest_win_seconds` behaviour.
+        let mut local = default_payload();
+        local.stats.classic_fastest_win_seconds = 240;
+        let mut remote = default_payload();
+        remote.stats.classic_fastest_win_seconds = 120;
+
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(merged.stats.classic_fastest_win_seconds, 120);
+    }
+
+    #[test]
+    fn merge_per_mode_fastest_both_zero_stays_zero() {
+        // Neither side has a win — the field must remain 0 rather than
+        // accidentally becoming non-zero.
+        let local = default_payload();
+        let remote = default_payload();
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(merged.stats.classic_fastest_win_seconds, 0);
+        assert_eq!(merged.stats.zen_fastest_win_seconds, 0);
+        assert_eq!(merged.stats.challenge_fastest_win_seconds, 0);
+    }
+
+    #[test]
+    fn merge_per_mode_fastest_local_real_remote_zero() {
+        // Symmetric to `merge_per_mode_fastest_ignores_zero`: local has the
+        // real time, remote is the zero-side. The merge must keep local's
+        // value rather than flooring to 0.
+        let mut local = default_payload();
+        local.stats.challenge_fastest_win_seconds = 300;
+        let remote = default_payload();
+        let (merged, _) = merge(&local, &remote);
+        assert_eq!(merged.stats.challenge_fastest_win_seconds, 300);
+    }
+
+    #[test]
+    fn merge_longest_streak_never_below_current_streak() {
+        // If a payload's `daily_challenge_longest_streak` was never written
+        // (legacy file) but its `daily_challenge_streak` is non-zero, the
+        // merged longest must reflect at least the current streak so the
+        // two values stay coherent.
+        let mut local = default_payload();
+        local.progress.daily_challenge_streak = 7;
+        local.progress.daily_challenge_longest_streak = 0; // legacy
+        let remote = default_payload();
+        let (merged, _) = merge(&local, &remote);
+        assert!(
+            merged.progress.daily_challenge_longest_streak >= 7,
+            "longest streak must be at least as large as the merged current streak"
+        );
+    }
 }

solitaire_sync/src/progress.rs

@@ -18,6 +18,13 @@ pub fn level_for_xp(xp: u64) -> u32 {
     }
 }
 
+/// Maximum number of dates retained in [`PlayerProgress::daily_challenge_history`].
+///
+/// Bounds the per-player file size across years of play. ~365 entries is
+/// roughly a year of daily completions, far more than the 14-day window the
+/// in-game calendar surfaces.
+pub const DAILY_CHALLENGE_HISTORY_CAP: usize = 365;
+
 /// Persisted player progression state.
 ///
 /// Mutation helpers such as `add_xp`, `record_daily_completion`, etc. are
@@ -45,6 +52,14 @@ pub struct PlayerProgress {
     /// Index of the next Challenge-mode seed to serve to this player.
     #[serde(default)]
     pub challenge_index: u32,
+    /// All dates the player has completed the daily challenge, in
+    /// chronological ascending order. Bounded to the most recent 365
+    /// entries so file size stays bounded across years of play.
+    #[serde(default)]
+    pub daily_challenge_history: Vec<NaiveDate>,
+    /// Longest daily-challenge streak ever achieved on this profile.
+    #[serde(default)]
+    pub daily_challenge_longest_streak: u32,
     /// Wall-clock time of the last modification (used for conflict detection).
     pub last_modified: DateTime<Utc>,
 }
@@ -61,6 +76,8 @@ impl Default for PlayerProgress {
             unlocked_card_backs: vec![0],
             unlocked_backgrounds: vec![0],
             challenge_index: 0,
+            daily_challenge_history: Vec::new(),
+            daily_challenge_longest_streak: 0,
             last_modified: DateTime::UNIX_EPOCH,
         }
     }
@@ -114,6 +131,12 @@ impl PlayerProgress {
     /// - Completion the day after the previous: streak increments.
     /// - Same day as the previous: no-op (idempotent).
     ///
+    /// On every fresh completion, `date` is appended to
+    /// `daily_challenge_history` (kept sorted ascending and capped at
+    /// [`DAILY_CHALLENGE_HISTORY_CAP`] entries) and
+    /// `daily_challenge_longest_streak` is bumped if the current streak
+    /// exceeds it.
+    ///
     /// Returns `true` if this call recorded a fresh completion.
     pub fn record_daily_completion(&mut self, date: NaiveDate) -> bool {
         match self.daily_challenge_last_completed {
@@ -126,6 +149,19 @@ impl PlayerProgress {
             }
         }
         self.daily_challenge_last_completed = Some(date);
+        // Append to history (defensive against duplicates and out-of-order
+        // dates so a hand-edited or merged file can't corrupt the order).
+        if !self.daily_challenge_history.contains(&date) {
+            self.daily_challenge_history.push(date);
+            self.daily_challenge_history.sort();
+            if self.daily_challenge_history.len() > DAILY_CHALLENGE_HISTORY_CAP {
+                let excess = self.daily_challenge_history.len() - DAILY_CHALLENGE_HISTORY_CAP;
+                self.daily_challenge_history.drain(0..excess);
+            }
+        }
+        if self.daily_challenge_streak > self.daily_challenge_longest_streak {
+            self.daily_challenge_longest_streak = self.daily_challenge_streak;
+        }
         self.last_modified = Utc::now();
         true
     }
@@ -320,4 +356,85 @@ mod tests {
         p.record_daily_completion(date(2026, 4, 22)); // skip the 21st
         assert_eq!(p.daily_challenge_streak, 1, "gap must reset streak");
     }
+
+    // -----------------------------------------------------------------------
+    // record_daily_completion — history + longest-streak side effects
+    // -----------------------------------------------------------------------
+
+    #[test]
+    fn record_daily_completion_appends_to_history_in_chronological_order() {
+        let mut p = PlayerProgress::default();
+        assert!(p.daily_challenge_history.is_empty());
+        p.record_daily_completion(date(2026, 4, 20));
+        p.record_daily_completion(date(2026, 4, 21));
+        p.record_daily_completion(date(2026, 4, 22));
+        assert_eq!(
+            p.daily_challenge_history,
+            vec![
+                date(2026, 4, 20),
+                date(2026, 4, 21),
+                date(2026, 4, 22),
+            ],
+            "history should hold all three completions in ascending order"
+        );
+    }
+
+    #[test]
+    fn record_daily_completion_same_day_does_not_duplicate_history() {
+        let mut p = PlayerProgress::default();
+        p.record_daily_completion(date(2026, 4, 20));
+        p.record_daily_completion(date(2026, 4, 20));
+        assert_eq!(
+            p.daily_challenge_history,
+            vec![date(2026, 4, 20)],
+            "same-day completion is a no-op and must not duplicate history"
+        );
+    }
+
+    #[test]
+    fn record_daily_completion_updates_longest_streak() {
+        let mut p = PlayerProgress::default();
+        // Three-day streak: longest jumps from 0 → 3.
+        p.record_daily_completion(date(2026, 4, 20));
+        p.record_daily_completion(date(2026, 4, 21));
+        p.record_daily_completion(date(2026, 4, 22));
+        assert_eq!(p.daily_challenge_streak, 3);
+        assert_eq!(p.daily_challenge_longest_streak, 3);
+
+        // Gap resets the current streak — longest must NOT regress.
+        p.record_daily_completion(date(2026, 4, 25));
+        assert_eq!(p.daily_challenge_streak, 1);
+        assert_eq!(
+            p.daily_challenge_longest_streak, 3,
+            "longest_streak must never regress after a gap"
+        );
+
+        // Two-day streak — still below longest, so longest stays at 3.
+        p.record_daily_completion(date(2026, 4, 26));
+        assert_eq!(p.daily_challenge_streak, 2);
+        assert_eq!(p.daily_challenge_longest_streak, 3);
+    }
+
+    #[test]
+    fn daily_challenge_history_is_capped_at_max() {
+        // Push DAILY_CHALLENGE_HISTORY_CAP + 5 consecutive days; the
+        // earliest five must be evicted and the most recent CAP retained.
+        let mut p = PlayerProgress::default();
+        let start = date(2024, 1, 1);
+        let total = DAILY_CHALLENGE_HISTORY_CAP + 5;
+        for offset in 0..total {
+            p.record_daily_completion(start + Duration::days(offset as i64));
+        }
+        assert_eq!(p.daily_challenge_history.len(), DAILY_CHALLENGE_HISTORY_CAP);
+        // Oldest retained is `start + 5` (we dropped the first 5).
+        assert_eq!(
+            p.daily_challenge_history.first().copied(),
+            Some(start + Duration::days(5))
+        );
+        // Newest retained is the last date pushed.
+        assert_eq!(
+            p.daily_challenge_history.last().copied(),
+            Some(start + Duration::days(total as i64 - 1))
+        );
+    }
 }

solitaire_sync/src/stats.rs

@@ -33,6 +33,56 @@ pub struct StatsSnapshot {
     pub draw_one_wins: u32,
     /// Wins achieved in Draw-Three mode.
     pub draw_three_wins: u32,
+
+    // -----------------------------------------------------------------
+    // Per-mode bests
+    //
+    // These mirror `best_single_score` / `fastest_win_seconds` but
+    // narrowed to one [`solitaire_core::game_state::GameMode`]. They are
+    // additive: lifetime totals continue to track across all modes, and
+    // legacy `stats.json` files load to 0 for every new field via
+    // `#[serde(default)]`.
+    //
+    // Time-Attack and Daily-Challenge are intentionally absent here:
+    // - Time Attack has its own session-level scoring (count of wins
+    //   inside a 10-minute window); a per-game best wouldn't compose.
+    // - Daily Challenge uses Classic scoring rules and so already
+    //   contributes to `classic_*` here.
+    //
+    // Sentinel for `*_fastest_win_seconds` is `0` (not `u64::MAX`),
+    // because legacy files deserialise unknown fields to the type's
+    // `Default::default()` — and `u64::default()` is 0. The merge logic
+    // and the UI must therefore treat 0 as "no win recorded yet".
+    // -----------------------------------------------------------------
+
+    /// Best single score achieved in Classic mode (Draw-One or Draw-Three).
+    /// 0 means "no Classic win yet".
+    #[serde(default)]
+    pub classic_best_score: u32,
+
+    /// Fastest Classic-mode win time, in seconds. 0 means "no Classic win yet".
+    #[serde(default)]
+    pub classic_fastest_win_seconds: u64,
+
+    /// Best single score achieved in Zen mode. Zen has no time pressure but
+    /// scoring is still on, so players who care about it still play for a high.
+    /// 0 means "no Zen win yet".
+    #[serde(default)]
+    pub zen_best_score: u32,
+
+    /// Fastest Zen-mode win time, in seconds. 0 means "no Zen win yet".
+    #[serde(default)]
+    pub zen_fastest_win_seconds: u64,
+
+    /// Best single score achieved in Challenge mode (the hardest mode — separate
+    /// leaderboard). 0 means "no Challenge win yet".
+    #[serde(default)]
+    pub challenge_best_score: u32,
+
+    /// Fastest Challenge-mode win time, in seconds. 0 means "no Challenge win yet".
+    #[serde(default)]
+    pub challenge_fastest_win_seconds: u64,
+
     /// Wall-clock time of the last modification (used for conflict detection).
     pub last_modified: DateTime<Utc>,
 }
@@ -51,6 +101,12 @@ impl Default for StatsSnapshot {
             best_single_score: 0,
             draw_one_wins: 0,
             draw_three_wins: 0,
+            classic_best_score: 0,
+            classic_fastest_win_seconds: 0,
+            zen_best_score: 0,
+            zen_fastest_win_seconds: 0,
+            challenge_best_score: 0,
+            challenge_fastest_win_seconds: 0,
             last_modified: DateTime::UNIX_EPOCH,
         }
     }
@@ -147,4 +203,20 @@ mod tests {
         assert_eq!(s.win_streak_best, 7, "best streak must not be reduced on abandon");
         assert_eq!(s.win_streak_current, 0);
     }
+
+    #[test]
+    fn per_mode_fields_default_to_zero() {
+        // The new per-mode fields must default to 0 — both in the explicit
+        // `Default` impl and (because of `#[serde(default)]`) for any
+        // legacy payload that omits them. The legacy-JSON deserialise
+        // round-trip lives in `solitaire_data::stats` where `serde_json`
+        // is in scope.
+        let s = StatsSnapshot::default();
+        assert_eq!(s.classic_best_score, 0);
+        assert_eq!(s.classic_fastest_win_seconds, 0);
+        assert_eq!(s.zen_best_score, 0);
+        assert_eq!(s.zen_fastest_win_seconds, 0);
+        assert_eq!(s.challenge_best_score, 0);
+        assert_eq!(s.challenge_fastest_win_seconds, 0);
+    }
 }

solitaire_wasm/Cargo.toml

@@ -0,0 +1,29 @@
+[package]
+name    = "solitaire_wasm"
+version.workspace = true
+license.workspace = true
+edition.workspace = true
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[dependencies]
+solitaire_core = { path = "../solitaire_core" }
+serde          = { workspace = true }
+serde_json     = { workspace = true }
+chrono         = { workspace = true }
+wasm-bindgen   = "0.2"
+serde-wasm-bindgen = "0.6"
+console_error_panic_hook = { version = "0.1", optional = true }
+
+# `getrandom` is pulled in transitively via `rand` (used by
+# `solitaire_core::Deck::shuffle`). On `wasm32-unknown-unknown` it
+# needs an explicit JS-backend feature, otherwise the build aborts
+# with a "wasm32-unknown-unknown is not a supported target" error.
+# Pinning here forces the feature on without us having to pollute
+# `solitaire_core`'s deps with wasm-only flags.
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.3", features = ["wasm_js"] }
+
+[features]
+default = ["console_error_panic_hook"]

solitaire_wasm/src/lib.rs

@@ -0,0 +1,272 @@
+//! WebAssembly bindings for browser-side replay playback.
+//!
+//! The web replay player at `<server>/replays/<id>` fetches a [`Replay`]
+//! JSON via `GET /api/replays/:id`, hands it to [`ReplayPlayer::new`],
+//! and then advances frame-by-frame with [`ReplayPlayer::step`]. Each
+//! step applies one [`ReplayMove`] to the underlying `GameState` and
+//! returns the resulting pile snapshot as JSON for the JS layer to
+//! render.
+//!
+//! The state machine is the same Rust [`solitaire_core::GameState`]
+//! the desktop client uses, so the two implementations cannot drift —
+//! same seed + same input list = same pile state at every step,
+//! regardless of which platform replays the game.
+//!
+//! The crate intentionally does **not** depend on `solitaire_data`
+//! (which pulls `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 contract.
+
+use chrono::NaiveDate;
+use serde::{Deserialize, Serialize};
+use solitaire_core::card::Suit;
+use solitaire_core::game_state::{DrawMode, GameMode, GameState};
+use solitaire_core::pile::PileType;
+use wasm_bindgen::prelude::*;
+
+/// Mirrors the variants of `solitaire_data::ReplayMove` v2 (atomic
+/// player inputs, post-StockClick refinement). Only the JSON shape
+/// matters for cross-crate compatibility.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub enum ReplayMove {
+    Move {
+        from: PileType,
+        to: PileType,
+        count: usize,
+    },
+    StockClick,
+}
+
+/// Mirrors `solitaire_data::Replay` v2.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct Replay {
+    #[serde(default)]
+    pub schema_version: u32,
+    pub seed: u64,
+    pub draw_mode: DrawMode,
+    pub mode: GameMode,
+    pub time_seconds: u64,
+    pub final_score: i32,
+    pub recorded_at: NaiveDate,
+    pub moves: Vec<ReplayMove>,
+}
+
+/// JS-friendly snapshot of a `GameState` at a particular replay step.
+#[derive(Debug, Clone, Serialize)]
+pub struct StateSnapshot {
+    pub step_idx: usize,
+    pub total_steps: usize,
+    pub score: i32,
+    pub move_count: u32,
+    pub is_won: bool,
+    pub stock: Vec<CardSnapshot>,
+    pub waste: Vec<CardSnapshot>,
+    /// Length 4 — one per foundation slot, in slot order (0..=3). The
+    /// claimed suit (if any) is the bottom card's suit.
+    pub foundations: [Vec<CardSnapshot>; 4],
+    /// Length 7 — one per tableau column (0..=6).
+    pub tableaus: [Vec<CardSnapshot>; 7],
+}
+
+/// One card, projected for the JS card renderer. `face_up = false`
+/// means the card back is drawn; in that case `suit` and `rank` are
+/// still set (so the renderer doesn't need separate "unknown" data),
+/// just hidden visually.
+#[derive(Debug, Clone, Copy, Serialize)]
+pub struct CardSnapshot {
+    pub id: u32,
+    /// `"clubs" | "diamonds" | "hearts" | "spades"`.
+    pub suit: &'static str,
+    /// 1-13, where 1 is Ace and 13 is King.
+    pub rank: u8,
+    pub face_up: bool,
+}
+
+impl From<&solitaire_core::card::Card> for CardSnapshot {
+    fn from(c: &solitaire_core::card::Card) -> Self {
+        Self {
+            id: c.id,
+            suit: match c.suit {
+                Suit::Clubs => "clubs",
+                Suit::Diamonds => "diamonds",
+                Suit::Hearts => "hearts",
+                Suit::Spades => "spades",
+            },
+            rank: c.rank.value(),
+            face_up: c.face_up,
+        }
+    }
+}
+
+/// Browser-side replay state machine. Owns a live `GameState` and the
+/// replay's move list; each `step()` applies the next move.
+#[wasm_bindgen]
+pub struct ReplayPlayer {
+    game: GameState,
+    moves: Vec<ReplayMove>,
+    step_idx: usize,
+}
+
+// Native-callable methods. Used by both the wasm-bindgen interface
+// below and by unit tests, which can't go through `serde_wasm_bindgen`
+// (it panics on non-wasm targets).
+impl ReplayPlayer {
+    /// Construct from a raw replay JSON string. Returns the parsing
+    /// error as a `String` so the wasm-bindgen wrapper can convert
+    /// it to a `JsValue` and tests can assert on it directly.
+    pub fn from_json(replay_json: &str) -> Result<Self, String> {
+        let replay: Replay =
+            serde_json::from_str(replay_json).map_err(|e| format!("invalid replay JSON: {e}"))?;
+        let game =
+            GameState::new_with_mode(replay.seed, replay.draw_mode.clone(), replay.mode);
+        Ok(Self {
+            game,
+            moves: replay.moves,
+            step_idx: 0,
+        })
+    }
+
+    /// Apply the next move. Returns `None` once the list is exhausted.
+    pub fn step_native(&mut self) -> Option<StateSnapshot> {
+        if self.step_idx >= self.moves.len() {
+            return None;
+        }
+        let mv = self.moves[self.step_idx].clone();
+        let _ = match mv {
+            ReplayMove::Move { from, to, count } => self.game.move_cards(from, to, count),
+            ReplayMove::StockClick => self.game.draw(),
+        };
+        self.step_idx += 1;
+        Some(self.snapshot())
+    }
+
+    fn snapshot(&self) -> StateSnapshot {
+        let pile_cards = |t: PileType| -> Vec<CardSnapshot> {
+            self.game
+                .piles
+                .get(&t)
+                .map(|p| p.cards.iter().map(CardSnapshot::from).collect())
+                .unwrap_or_default()
+        };
+        let foundations: [Vec<CardSnapshot>; 4] = [
+            pile_cards(PileType::Foundation(0)),
+            pile_cards(PileType::Foundation(1)),
+            pile_cards(PileType::Foundation(2)),
+            pile_cards(PileType::Foundation(3)),
+        ];
+        let tableaus: [Vec<CardSnapshot>; 7] = [
+            pile_cards(PileType::Tableau(0)),
+            pile_cards(PileType::Tableau(1)),
+            pile_cards(PileType::Tableau(2)),
+            pile_cards(PileType::Tableau(3)),
+            pile_cards(PileType::Tableau(4)),
+            pile_cards(PileType::Tableau(5)),
+            pile_cards(PileType::Tableau(6)),
+        ];
+        StateSnapshot {
+            step_idx: self.step_idx,
+            total_steps: self.moves.len(),
+            score: self.game.score,
+            move_count: self.game.move_count,
+            is_won: self.game.is_won,
+            stock: pile_cards(PileType::Stock),
+            waste: pile_cards(PileType::Waste),
+            foundations,
+            tableaus,
+        }
+    }
+}
+
+// JS-facing surface. Thin wrapper around the native API: serialises
+// `StateSnapshot` to `JsValue` via `serde_wasm_bindgen` and converts
+// `String` errors to `JsValue` strings. Native unit tests bypass this
+// layer because `serde_wasm_bindgen::to_value` panics off-target.
+#[wasm_bindgen]
+impl ReplayPlayer {
+    /// Construct from a raw replay JSON string.
+    #[wasm_bindgen(constructor)]
+    pub fn new(replay_json: &str) -> Result<ReplayPlayer, JsValue> {
+        #[cfg(feature = "console_error_panic_hook")]
+        console_error_panic_hook::set_once();
+        Self::from_json(replay_json).map_err(|e| JsValue::from_str(&e))
+    }
+
+    /// Snapshot the current `GameState` as a JS object (see `StateSnapshot`).
+    pub fn state(&self) -> JsValue {
+        serde_wasm_bindgen::to_value(&self.snapshot()).unwrap_or(JsValue::NULL)
+    }
+
+    /// Apply the next move; returns the post-step snapshot, or `null`
+    /// once the move list is exhausted.
+    pub fn step(&mut self) -> JsValue {
+        match self.step_native() {
+            Some(snap) => serde_wasm_bindgen::to_value(&snap).unwrap_or(JsValue::NULL),
+            None => JsValue::NULL,
+        }
+    }
+
+    /// Total number of moves the replay contains.
+    pub fn total_steps(&self) -> usize {
+        self.moves.len()
+    }
+
+    /// 0-indexed position of the next move to apply.
+    pub fn step_idx(&self) -> usize {
+        self.step_idx
+    }
+
+    /// Returns `true` once every move has been applied.
+    pub fn is_finished(&self) -> bool {
+        self.step_idx >= self.moves.len()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn sample_replay_json() -> String {
+        // Minimal v2 replay: seed 42, two stock clicks. Real winning
+        // replays will have many more moves; for the test we just
+        // verify deserialization + step() advances correctly.
+        r#"{
+            "schema_version": 2,
+            "seed": 42,
+            "draw_mode": "DrawOne",
+            "mode": "Classic",
+            "time_seconds": 60,
+            "final_score": 100,
+            "recorded_at": "2026-05-02",
+            "moves": ["StockClick", "StockClick"]
+        }"#
+        .to_string()
+    }
+
+    /// Constructing from a valid v2 replay JSON must succeed and
+    /// initialise step_idx to 0.
+    #[test]
+    fn new_initialises_step_idx_zero() {
+        let player = ReplayPlayer::from_json(&sample_replay_json()).expect("valid JSON");
+        assert_eq!(player.step_idx, 0);
+        assert_eq!(player.moves.len(), 2);
+    }
+
+    /// Each step advances the index; once exhausted, step_native returns None.
+    #[test]
+    fn steps_advance_then_terminate() {
+        let mut player = ReplayPlayer::from_json(&sample_replay_json()).expect("valid JSON");
+        assert!(player.step_native().is_some());
+        assert_eq!(player.step_idx, 1);
+        assert!(player.step_native().is_some());
+        assert_eq!(player.step_idx, 2);
+        assert!(player.step_native().is_none(), "no further steps");
+    }
+
+    /// Malformed JSON returns an error rather than panicking.
+    #[test]
+    fn invalid_json_returns_error() {
+        let result = ReplayPlayer::from_json("not valid json");
+        assert!(result.is_err());
+    }
+}