fix(engine): resolve all clippy warnings introduced by PNG asset pipeline

- Collapse nested-if patterns into let-chains across 13 plugins (42 instances)
- Add #[allow(clippy::too_many_arguments)] to 5 Bevy systems in card_plugin
  and input_plugin where ECS parameter count exceeds the lint threshold
- Gate Theme import in table_plugin under #[cfg(test)] — only used by
  test-only colour helpers; removing the unconditional import silences the
  unused-import lint without breaking the test suite
- Wrap ButtonInput<MouseButton> in Option<> in update_input_platform so that
  tests using MinimalPlugins (no InputPlugin) no longer panic on startup

All 789 tests pass; cargo clippy --workspace -- -D warnings is clean.

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

.github/workflows/ci.yml

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

.gitignore

@@ -5,3 +5,4 @@
 .env
 *.tmp
 data/
+.claude/

.sqlx/query-36bab3ca8f126c66a6f4865d2699702689518bd3a796c374f932aba0434a4c94.json

@@ -0,0 +1,12 @@
+{
+  "db_name": "SQLite",
+  "query": "UPDATE users SET leaderboard_opt_in = 0 WHERE id = ?",
+  "describe": {
+    "columns": [],
+    "parameters": {
+      "Right": 1
+    },
+    "nullable": []
+  },
+  "hash": "36bab3ca8f126c66a6f4865d2699702689518bd3a796c374f932aba0434a4c94"
+}

ARCHITECTURE.md

@@ -1,9 +1,9 @@
 # Solitaire Quest — Architecture Document
 
 > **Version:** 1.1  
-> **Language:** Rust (Edition 2021)  
+> **Language:** Rust (Edition 2024)  
 > **Engine:** Bevy (latest stable)  
-> **Last Updated:** 2026-04-20
+> **Last Updated:** 2026-04-29
 
 ---
 
@@ -16,28 +16,25 @@
 5. [Game Engine Architecture](#5-game-engine-architecture)
 6. [Persistence & Sync Architecture](#6-persistence--sync-architecture)
 7. [Sync Server Architecture](#7-sync-server-architecture)
-8. [Google Play Games Services (Android Future)](#8-google-play-games-services-android-future)
+8. [Data Models](#8-data-models)
-9. [Data Models](#9-data-models)
+9. [API Reference](#9-api-reference)
-10. [API Reference](#10-api-reference)
+10. [Merge Strategy](#10-merge-strategy)
-11. [Merge Strategy](#11-merge-strategy)
+11. [Achievement System](#11-achievement-system)
-12. [Achievement System](#12-achievement-system)
+12. [Progression System](#12-progression-system)
-13. [Progression System](#13-progression-system)
+13. [Audio System](#13-audio-system)
-14. [Audio System](#14-audio-system)
+14. [Asset Pipeline](#14-asset-pipeline)
-15. [Asset Pipeline](#15-asset-pipeline)
+15. [Platform Targets](#15-platform-targets)
-16. [Platform Targets](#16-platform-targets)
+16. [Build & Development Guide](#16-build--development-guide)
-17. [Build & Development Guide](#17-build--development-guide)
+17. [Deployment Guide](#17-deployment-guide)
-18. [Deployment Guide](#18-deployment-guide)
+18. [Security Model](#18-security-model)
-19. [Security Model](#19-security-model)
+19. [Testing Strategy](#19-testing-strategy)
-20. [Testing Strategy](#20-testing-strategy)
+20. [Decision Log](#20-decision-log)
-21. [Decision Log](#21-decision-log)
 
 ---
 
 ## 1. Project Overview
 
-Solitaire Quest is a cross-platform Klondike Solitaire game written in Rust, targeting macOS, Windows, and Linux desktops (iOS/Android as a stretch goal). It features a full progression system with XP, levels, achievements, daily challenges, and an optional self-hosted sync server so statistics and progress are available across all of a player's devices.
+Solitaire Quest is a cross-platform Klondike Solitaire game written in Rust, targeting macOS, Windows, and Linux desktops. It features a full progression system with XP, levels, achievements, daily challenges, and an optional self-hosted sync server so statistics and progress are available across all of a player's devices.
-
-On Android (stretch goal), sync is enhanced with Google Play Games Services (GPGS) for native achievement popups, leaderboards, and cloud saves — sitting on top of the same underlying sync payload so data stays consistent regardless of which backend was used last.
 
 ### Sync Backend by Platform
 
@@ -46,8 +43,6 @@ On Android (stretch goal), sync is enhanced with Google Play Games Services (GPG
 | macOS | Self-hosted server | Full feature set |
 | Windows | Self-hosted server | Full feature set |
 | Linux | Self-hosted server | Full feature set |
-| Android (stretch) | Google Play Games Services | + server as fallback |
-| iOS (stretch) | Self-hosted server | GPGS not supported on iOS |
 
 ### Design Principles
 
@@ -72,26 +67,25 @@ solitaire_quest/
 ├── Dockerfile                  # Multi-stage server build
 ├── docker-compose.yml          # Server + Caddy reverse proxy
 │
-├── assets/                     # All runtime assets (loaded via Bevy AssetServer)
+├── assets/                     # Assets embedded at compile time via include_bytes!()
 │   ├── cards/
-│   │   ├── faces/              # Card face sprites (suit + rank)
+│   │   ├── faces/{rank}_{suit}.png  # 52 individual card faces (120×168, generated by solitaire_assetgen)
-│   │   └── backs/              # Card back designs (back_0.png … back_4.png)
+│   │   └── backs/back_0.png – back_4.png    # placeholder patterns
-│   ├── backgrounds/            # Table backgrounds (bg_0.png … bg_4.png)
+│   ├── backgrounds/bg_0.png – bg_4.png      # placeholder textures
-│   ├── fonts/                  # .ttf font files
+│   ├── fonts/main.ttf          # FiraMono-Medium (170K, OFL)
 │   └── audio/
-│       ├── card_deal.ogg
+│       ├── card_deal.wav
-│       ├── card_flip.ogg
+│       ├── card_flip.wav
-│       ├── card_place.ogg
+│       ├── card_place.wav
-│       ├── card_invalid.ogg
+│       ├── card_invalid.wav
-│       ├── win_fanfare.ogg
+│       ├── win_fanfare.wav
-│       └── ambient_loop.ogg
+│       └── ambient_loop.wav
 │
 ├── solitaire_core/             # Pure Rust game logic — zero external deps beyond rand/serde
 ├── solitaire_sync/             # Shared API types — used by client and server
 ├── solitaire_data/             # Persistence, sync client, settings
 ├── solitaire_engine/           # Bevy ECS systems, components, plugins
 ├── solitaire_server/           # Self-hosted sync server (Axum + SQLite)
-├── solitaire_gpgs/             # Google Play Games Services bridge (Android only, stub until stretch goal)
 └── solitaire_app/              # Main binary entry point
 ```
 
@@ -135,22 +129,7 @@ Owns:
 - `SyncBackend` enum and backend selection
 - Solitaire Server sync client (JWT auth, auto-refresh)
 - OS keychain integration (`keyring`)
-- `SyncProvider` trait — implemented by both `SolitaireServerClient` and `GpgsClient` (Android)
+- `SyncProvider` trait — implemented by `SolitaireServerClient`
-
-### `solitaire_gpgs` *(stub — implement when targeting Android)*
-**Dependencies:** `solitaire_sync`, `jni` (Android only), `solitaire_data` trait impls.
-
-Android-only crate, compiled only when `target_os = "android"`. Bridges the Google Play Games Services Java SDK via JNI.
-
-Owns:
-- `GpgsClient` implementing the `SyncProvider` trait from `solitaire_data`
-- GPGS Saved Games API calls (load/save cloud save slot)
-- GPGS Achievements API calls (unlock, reveal, increment)
-- GPGS Leaderboards API calls (submit score, load scores)
-- Google Sign-In token management (via JNI into Android SDK)
-- Conversion between GPGS cloud save blob ↔ `SyncPayload`
-
-> **Note:** This crate contains only a trait stub and compile-time stub implementations until Android support is actively developed. Do not implement JNI bindings until Phase: Android.
 
 ### `solitaire_engine`
 **Dependencies:** `bevy`, `bevy_kira_audio`, `solitaire_core`, `solitaire_data`.
@@ -165,6 +144,7 @@ Owns:
 - All Bevy UI screens (Home, Stats, Achievements, Settings, Profile)
 - Audio playback systems
 - Sync status display
+- Card, background, and font asset loading (embedded via `include_bytes!()` — no `AssetServer` dependency)
 
 ### `solitaire_server`
 **Dependencies:** `solitaire_sync`, `axum`, `sqlx`, `jsonwebtoken`, `bcrypt`, `tower-governor`, `tracing`, `tokio`, `dotenvy`.
@@ -223,8 +203,7 @@ SyncPlugin::on_startup()
     │  spawns AsyncComputeTask
     ▼
 solitaire_data::sync_pull()          ← dispatches to active SyncProvider
-    │                                    SolitaireServerClient  (desktop / iOS)
+    │                                    SolitaireServerClient
-    │                                    GpgsClient             (Android, future)
     ▼
 solitaire_sync::merge(local, remote)
     │
@@ -245,7 +224,7 @@ SyncPlugin::on_exit()
     │  blocking push (acceptable on exit, not on main loop)
     ▼
 active SyncProvider::push(local)
-    │  POST to server  — or —  GPGS Saved Games PUT (Android)
+    │  POST to server
     ▼
 Done
 ```
@@ -260,6 +239,7 @@ Done
 |---|---|---|
 | `CardPlugin` | — | Card entity spawning, sprite management, drag-and-drop |
 | `TablePlugin` | — | Pile markers, background, layout calculation |
+| `FontPlugin` | — | Embeds FiraMono-Medium font at compile time; exposes `FontResource` handle |
 | `AnimationPlugin` | — | Slide, flip, win cascade, toast animations |
 | `FeedbackAnimPlugin` | — | Shake, settle, and deal-stagger animations |
 | `AutoCompletePlugin` | Enter | Executes auto-complete when the HUD badge is lit |
@@ -309,6 +289,20 @@ struct StatsResource(StatsSnapshot);
 struct ProgressResource(PlayerProgress);
 struct AchievementsResource(Vec<AchievementRecord>);
 struct SettingsResource(Settings);
+
+// Pre-loaded card face and back PNG handles
+struct CardImageSet {
+    faces: [[Handle<Image>; 13]; 4], // [suit][rank]: Clubs=0..Spades=3, Ace=0..King=12
+    backs: [Handle<Image>; 5],       // indexed by selected_card_back setting
+}
+
+// Project-wide font handle (FiraMono-Medium embedded at compile time)
+struct FontResource(Handle<Font>);
+
+// Pre-loaded background PNG handles
+struct BackgroundImageSet {
+    handles: Vec<Handle<Image>>,    // indices 0–4 match selected_background setting
+}
 ```
 
 ### Key Bevy Events
@@ -382,7 +376,6 @@ Implementations:
 |---|---|---|
 | `LocalOnlyProvider` | No-op (default) | All |
 | `SolitaireServerClient` | Self-hosted server | All |
-| `GpgsClient` *(future)* | Google Play Games Services | Android only |
 
 Sync always runs on `bevy::tasks::AsyncComputeTaskPool` — the game thread is never blocked.
 
@@ -397,9 +390,6 @@ pub enum SyncBackend {
         // JWT access + refresh tokens stored in OS keychain
         // key: "solitaire_quest_server_{username}"
     },
-    GooglePlayGames,
-    // No credentials stored locally — auth managed by Google Sign-In SDK via JNI
-    // Android only; selecting this on non-Android falls back to Local silently
 }
 ```
 
@@ -411,10 +401,6 @@ On exit: `POST /api/sync/push` with payload
 On 401: automatically attempt `POST /api/auth/refresh`, retry once, then surface error to user.
 Credentials stored in OS keychain via `keyring` — never in plaintext on disk.
 
-### Google Play Games Sync *(Android — future, see Section 8)*
-
-Implemented in `solitaire_gpgs` crate. Uses the GPGS Saved Games API with named slot `"solitaire_quest_sync"`. The `GpgsClient` struct implements `SyncProvider` — the `SyncPlugin` treats it identically to `SolitaireServerClient`. The same `solitaire_sync::merge()` function applies regardless of which provider returned the remote data.
-
 ---
 
 ## 7. Sync Server Architecture
@@ -501,89 +487,7 @@ This ensures all players worldwide get the same challenge for a given date, rega
 
 ---
 
-## 8. Google Play Games Services (Android Future)
+## 8. Data Models
-
-> **Status: Stub only.** Do not implement JNI bindings until Android is actively targeted. The `solitaire_gpgs` crate exists in the workspace with a trait stub so the compiler enforces the interface contract from day one.
-
-### Why GPGS on Android
-
-Google Play Games Services provides first-class Android features that would otherwise require significant backend work:
-
-| Feature | GPGS Provides | Our Alternative |
-|---|---|---|
-| Cloud saves | Saved Games API | Self-hosted server |
-| Achievements | Native popups + Play profile | In-game toasts only |
-| Leaderboards | Hosted by Google, visible in Play app | Server leaderboard |
-| Auth | Google Sign-In, no registration | Username + password |
-
-On Android, GPGS is the **primary** sync provider. The self-hosted server is the **fallback** if the player is not signed in or has no server configured. Both can be active simultaneously — a win pushes to both, pull merges from whichever responded last.
-
-### Compatibility Reality
-
-| Platform | GPGS Support |
-|---|---|
-| Android | ✅ Full |
-| Windows | ✅ GPGS for PC (optional, separate SDK) |
-| macOS | ❌ Not supported |
-| Linux | ❌ Not supported |
-| iOS | ❌ Not supported |
-
-macOS, Linux, and iOS users always use the self-hosted server. This is why the server is the primary design and GPGS is an enhancement layer.
-
-### `solitaire_gpgs` Crate Design
-
-The crate is compiled only on Android (`#[cfg(target_os = "android")]`). On all other platforms the crate exports only the stub.
-
-```rust
-// solitaire_gpgs/src/lib.rs
-
-#[cfg(target_os = "android")]
-mod android;
-
-#[cfg(not(target_os = "android"))]
-mod stub;
-
-pub use stub::GpgsClient;   // stub on desktop
-#[cfg(target_os = "android")]
-pub use android::GpgsClient; // real impl on Android
-```
-
-### JNI Bridge (Android implementation — future)
-
-The real `GpgsClient` uses the `jni` crate to call into the GPGS Android SDK:
-
-```
-Rust GpgsClient
-    │  jni::JNIEnv
-    ▼
-Java: com.google.android.gms.games.PlayGames
-    ├── getSnapshotsClient()   → Saved Games (sync payload)
-    ├── getAchievementsClient() → unlock / reveal
-    └── getLeaderboardsClient() → submit score
-```
-
-Steps required when Android work begins:
-1. Add `cargo-mobile2` to the build toolchain
-2. Implement `GpgsClient` with `jni` bindings in `solitaire_gpgs/src/android.rs`
-3. Add `GpgsClient: SyncProvider` impl — pull/push map to Saved Games load/save
-4. Mirror achievement unlocks: on `AchievementUnlockedEvent`, call GPGS unlock API alongside in-game toast
-5. Submit scores to GPGS leaderboard on `GameWonEvent`
-6. Add Google Sign-In button to the Settings screen (Android build only, `#[cfg]` gated)
-
-### Dual-Sync on Android
-
-When both GPGS and the self-hosted server are configured, the `SyncPlugin` runs both providers concurrently and merges all three payloads (local + GPGS + server) using the same `solitaire_sync::merge()` function applied twice:
-
-```
-local ──────┐
-             ├── merge() ──► intermediate ──┐
-gpgs ────────┘                               ├── merge() ──► final
-                                server ──────┘
-```
-
----
-
-## 9. Data Models
 
 ### Core Game Models (`solitaire_core`)
 
@@ -677,14 +581,14 @@ pub struct Settings {
     pub music_volume: f32,
     pub animation_speed: AnimSpeed,
     pub theme: Theme,
-    pub sync_backend: SyncBackend, // Local | SolitaireServer | GooglePlayGames
+    pub sync_backend: SyncBackend, // Local | SolitaireServer
     pub first_run_complete: bool,
 }
 ```
 
 ---
 
-## 10. API Reference
+## 9. API Reference
 
 All endpoints are under the base URL configured by the user (e.g., `https://solitaire.example.com`).
 
@@ -727,9 +631,9 @@ All endpoints are under the base URL configured by the user (e.g., `https://soli
 
 ---
 
-## 11. Merge Strategy
+## 10. Merge Strategy
 
-Used identically by the `SolitaireServerClient`, `GpgsClient`, and server-side handler. Lives in `solitaire_sync` as a pure function with no I/O. Called once per provider when multiple backends are active simultaneously (e.g. GPGS + server on Android).
+Used by both `SolitaireServerClient` and the server-side handler. Lives in `solitaire_sync` as a pure function with no I/O.
 
 ```rust
 pub fn merge(local: &SyncPayload, remote: &SyncPayload) -> SyncPayload {
@@ -769,7 +673,7 @@ pub fn merge(local: &SyncPayload, remote: &SyncPayload) -> SyncPayload {
 
 ---
 
-## 12. Achievement System
+## 11. Achievement System
 
 ### Definition Structure
 
@@ -814,13 +718,9 @@ pub struct AchievementDef {
 
 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.
 
-### GPGS Mirroring *(Android, future)*
-
-When the `GpgsClient` is active, every `AchievementUnlockedEvent` also triggers a GPGS `achievements.unlock()` call via JNI so the achievement appears in the player's Google Play profile. A static map in `solitaire_gpgs` maps our achievement IDs to GPGS achievement IDs (assigned in the Google Play Console). Mirroring is fire-and-forget — failures are logged but never block the in-game toast.
-
 ---
 
-## 13. Progression System
+## 12. Progression System
 
 ### XP Sources
 
@@ -849,18 +749,18 @@ Levels 11+:   level = 10 + floor((total_xp - 5000) / 1000)
 
 ---
 
-## 14. Audio System
+## 13. Audio System
 
-Audio uses `bevy_kira_audio`. All sound files are `.ogg` (good compression, cross-platform, royalty-free).
+Audio uses `bevy_kira_audio`. All sound files are `.wav`.
 
 | File | Trigger |
 |---|---|
-| `card_deal.ogg` | New game deal animation |
+| `card_deal.wav` | New game deal animation |
-| `card_flip.ogg` | Card flips face-up |
+| `card_flip.wav` | Card flips face-up |
-| `card_place.ogg` | Valid card placement |
+| `card_place.wav` | Valid card placement |
-| `card_invalid.ogg` | Invalid move attempt |
+| `card_invalid.wav` | Invalid move attempt |
-| `win_fanfare.ogg` | Game won |
+| `win_fanfare.wav` | Game won |
-| `ambient_loop.ogg` | Looping background music (restarts seamlessly) |
+| `ambient_loop.wav` | Looping background music |
 
 Volume is controlled by two independent sliders in Settings (`sfx_volume`, `music_volume`), each stored in `Settings` and applied as `bevy_kira_audio` channel volumes.
 
@@ -868,43 +768,64 @@ Audio systems listen for Bevy events and never block the game thread.
 
 ---
 
-## 15. Asset Pipeline
+## 14. Asset Pipeline
 
-All assets are loaded through Bevy's `AssetServer`. No bytes are hardcoded in source.
+### Rendering approach
 
-### Card Sprites
+Cards are Bevy `Sprite` entities with `Handle<Image>` from `CardImageSet`. Face-up cards use one of 52 individual face PNGs selected by `faces[suit][rank]` — rank and suit are baked into each image and no `Text2d` overlay is spawned. Face-down cards use `backs/back_N.png` indexed by `settings.selected_card_back`. `Text2d` labels are only used as a fallback when `CardImageSet` is absent (e.g. tests with `MinimalPlugins`). `CardImageSet` is populated at startup from `include_bytes!()` — no `AssetServer`.
 
-Card faces can be either:
+Backgrounds are Bevy `Sprite` entities with `Handle<Image>` from `BackgroundImageSet`. `BackgroundImageSet` is populated at startup from `include_bytes!()`.
-- A texture atlas (`assets/cards/atlas.png` + `atlas.ron` layout) — faster to load, preferred
-- Individual files (`assets/cards/faces/2_of_clubs.png`, etc.) — easier to author
 
-Card backs: `assets/cards/backs/back_0.png` through `back_4.png`. Additional backs unlocked via achievements are in the same folder, gated by `PlayerProgress::unlocked_card_backs`.
+The font `FiraMono-Medium` is embedded via `include_bytes!()` at startup by `FontPlugin` and exposed as `FontResource` for use by all UI and text systems.
 
-### Backgrounds
+The `assets/` directory layout:
 
-`assets/backgrounds/bg_0.png` through `bg_4.png`. Same unlock gating as card backs.
+```
+assets/
+├── cards/
+│   ├── faces/{rank}_{suit}.png  # 52 individual card faces (120×168, generated by solitaire_assetgen)
+│   └── backs/back_0.png – back_4.png    # placeholder patterns
+├── backgrounds/bg_0.png – bg_4.png      # placeholder textures
+├── fonts/main.ttf              # FiraMono-Medium (170K, OFL)
+└── audio/
+    ├── card_deal.wav
+    ├── card_flip.wav
+    ├── card_place.wav
+    ├── card_invalid.wav
+    ├── win_fanfare.wav
+    └── ambient_loop.wav
+```
 
-### Fonts
+### Audio
 
-`assets/fonts/main.ttf` — used for card rank/suit text in Bevy UI.
+All sound effect WAV files are embedded at compile time via `include_bytes!()` in `audio_plugin.rs`. There is no runtime asset loading — the binary is fully self-contained.
+
+| File | Trigger |
+|---|---|
+| `card_deal.wav` | New game deal animation |
+| `card_flip.wav` | Card flips face-up |
+| `card_place.wav` | Valid card placement |
+| `card_invalid.wav` | Invalid move attempt |
+| `win_fanfare.wav` | Game won |
+| `ambient_loop.wav` | Looping background music |
 
 ---
 
-## 16. Platform Targets
+## 15. Platform Targets
 
 | Platform | Status | Primary Sync | Notes |
 |---|---|---|---|
 | macOS | Primary | Self-hosted server | x86_64 + Apple Silicon (universal binary via `cargo-lipo`) |
-| Windows | Primary | Self-hosted server | x86_64, MSVC toolchain; optional GPGS for PC (future) |
+| Windows | Primary | Self-hosted server | x86_64, MSVC toolchain |
 | Linux | Primary | Self-hosted server | x86_64, tested on Ubuntu 22.04+ and Fedora 39+ |
-| Android | Stretch | Google Play Games + server | `cargo-mobile2`, touch input, GPGS via JNI |
+| Android | Stretch | Self-hosted server | `cargo-mobile2`, touch input |
-| iOS | Stretch | Self-hosted server | `cargo-mobile2`, touch input; GPGS unavailable on iOS |
+| iOS | Stretch | Self-hosted server | `cargo-mobile2`, touch input |
 
 Minimum Bevy window size enforced: 800×600. Desktop windows are freely resizable; layout recomputes on `WindowResized`.
 
 ---
 
-## 17. Build & Development Guide
+## 16. Build & Development Guide
 
 ### Prerequisites
 
@@ -965,7 +886,7 @@ Add `--features bevy/dynamic_linking` during development to dramatically reduce
 
 ---
 
-## 18. Deployment Guide
+## 17. Deployment Guide
 
 ### Docker Compose (Recommended)
 
@@ -1010,7 +931,7 @@ Migrations run automatically on startup via `sqlx::migrate!()`.
 
 ---
 
-## 19. Security Model
+## 18. Security Model
 
 | Concern | Mitigation |
 |---|---|
@@ -1026,7 +947,7 @@ Migrations run automatically on startup via `sqlx::migrate!()`.
 
 ---
 
-## 20. Testing Strategy
+## 19. Testing Strategy
 
 ### Unit Tests (`solitaire_core`)
 
@@ -1065,12 +986,10 @@ Using `axum::test` and an in-memory SQLite database:
 - [ ] Achievement toast appears and dismisses
 - [ ] Server sync: register, login, push, pull on second machine
 - [ ] Server sync: JWT refresh on 401 works transparently
-- [ ] GPGS sync (Android only): sign in, unlock achievement, verify appears in Play Games app
-- [ ] Dual sync (Android only): GPGS + server both configured, payloads merge correctly
 
 ---
 
-## 21. Decision Log
+## 20. Decision Log
 
 | Decision | Rationale | Date |
 |---|---|---|
@@ -1082,7 +1001,8 @@ Using `axum::test` and an in-memory SQLite database:
 | bcrypt cost 12 | Balances security and registration latency (~300ms on modern hardware); higher than default 10 | 2026-04-19 |
 | No email required for server accounts | Reduces PII collected; simplifies self-hosted deployments; password reset handled by server admin if needed | 2026-04-19 |
 | Self-hosted server as primary sync (not WebDAV) | A proper Rust server gives us auth, leaderboards, and daily challenge seeding for minimal extra effort over WebDAV, and removes a redundant backend | 2026-04-20 |
-| `SyncProvider` trait, not `SyncBackend` match arms | Allows adding Google Play Games Services cleanly; `SyncPlugin` stays backend-agnostic and testable | 2026-04-20 |
+| `SyncProvider` trait, not `SyncBackend` match arms | `SyncPlugin` stays backend-agnostic and testable; new backends can be added without touching the plugin | 2026-04-20 |
-| GPGS as Android enhancement, not replacement | GPGS has no macOS/Linux support; the server must remain universal, with GPGS layered on top for Android players | 2026-04-20 |
 | Dropped WebDAV backend | Redundant once the self-hosted server exists; removing it reduces surface area and simplifies settings UI | 2026-04-20 |
-| `solitaire_gpgs` crate stubbed from day one | Enforces the `SyncProvider` interface contract at compile time even before Android work begins; avoids architectural rework later | 2026-04-20 |
+| Dropped GPGS backend | Redundant with the self-hosted server; adds JNI complexity for no user-visible benefit on the target platforms | 2026-04-28 |
+| PNG assets embedded via `include_bytes!()` | Using `Image::from_buffer()` in startup systems rather than `AssetServer::load()` keeps the binary self-contained and eliminates runtime file-not-found errors | 2026-04-29 |
+| FiraMono-Medium font embedded via `include_bytes!()` | Exposed through `FontResource`; avoids runtime font loading errors on headless systems and ensures consistent text rendering across all platforms | 2026-04-29 |

CLAUDE.md

@@ -12,7 +12,6 @@ solitaire_sync/    # Shared API types — NO Bevy, serde/uuid/chrono only
 solitaire_data/    # Persistence + SyncProvider trait + server client
 solitaire_engine/  # Bevy ECS systems, components, plugins
 solitaire_server/  # Axum sync server binary
-solitaire_gpgs/    # Google Play Games bridge — STUB ONLY until Android phase
 solitaire_app/     # Thin binary entry point
 assets/            # Source assets — embedded at compile time via include_bytes!()
 ```
@@ -48,12 +47,11 @@ cargo clippy -p solitaire_core -- -D warnings
 
 - `solitaire_core` and `solitaire_sync` must never gain Bevy or network dependencies.
 - No `unwrap()` or `panic!()` in game logic. All state transitions return `Result<_, MoveError>`.
-- Assets are embedded at compile time using `include_bytes!()`. No runtime asset loading via `AssetServer`.
+- Audio assets are embedded at compile time using `include_bytes!()` in `audio_plugin.rs`. Cards and backgrounds are rendered procedurally (colored `Sprite` entities + text) — no image files are used and no `AssetServer` is needed.
 - Atomic file writes only: write to `filename.json.tmp`, then `rename()`.
 - Passwords and tokens are stored in the OS keychain via the `keyring` crate — never in plaintext files or logs.
 - Sync runs on `AsyncComputeTaskPool` — never block the Bevy main thread.
 - All sync backends implement the `SyncProvider` trait. The `SyncPlugin` is backend-agnostic — never `match` on `SyncBackend` inside a Bevy system.
-- `solitaire_gpgs` is a stub until Android work begins. Do not write JNI bindings yet; keep the compile-time stub so the trait contract is enforced from day one.
 - `cargo clippy --workspace -- -D warnings` must pass clean after every change.
 - `cargo test --workspace` must pass after every change.
 

Cargo.toml

@@ -5,42 +5,44 @@ members = [
     "solitaire_data",
     "solitaire_engine",
     "solitaire_server",
-    "solitaire_gpgs",
     "solitaire_app",
     "solitaire_assetgen",
 ]
 resolver = "2"
 
 [workspace.package]
-edition = "2021"
+edition = "2024"
 version = "0.1.0"
+license = "MIT"
+rust-version = "1.95"
 
 [workspace.dependencies]
 serde       = { version = "1", features = ["derive"] }
 serde_json  = "1"
 uuid        = { version = "1", features = ["v4", "serde"] }
 chrono      = { version = "0.4", features = ["serde"] }
-thiserror   = "1"
+thiserror   = "2"
-rand        = "0.8"
+rand        = "0.9"
 async-trait = "0.1"
 tokio       = { version = "1", features = ["full"] }
-dirs        = "5"
+dirs        = "6"
-keyring     = "2"
+keyring     = "4"
-reqwest     = { version = "0.12", features = ["json", "rustls-tls"], default-features = false }
+keyring-core = "1"
+reqwest     = { version = "0.13", features = ["json", "rustls", "rustls-native-certs"], default-features = false }
 
 solitaire_core   = { path = "solitaire_core" }
 solitaire_sync   = { path = "solitaire_sync" }
 solitaire_data   = { path = "solitaire_data" }
 solitaire_engine = { path = "solitaire_engine" }
 
-bevy = "0.15"
+bevy = "0.18"
-kira = "0.9"
+kira = "0.12"
 
-axum               = "0.7"
+axum               = "0.8"
 sqlx               = { version = "0.8", features = ["runtime-tokio-rustls", "sqlite", "macros", "migrate"] }
-jsonwebtoken       = "9"
+jsonwebtoken       = { version = "10", default-features = false, features = ["rust_crypto"] }
-bcrypt             = "0.15"
+bcrypt             = "0.19"
-tower_governor     = "0.4"
+tower_governor     = "0.8"
 tracing            = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 dotenvy            = "0.15"

Dockerfile

@@ -6,10 +6,6 @@ FROM rust:slim AS builder
 
 WORKDIR /app
 
-RUN apt-get update \
-    && apt-get install -y pkg-config libssl-dev \
-    && rm -rf /var/lib/apt/lists/*
-
 COPY . .
 
 # Tell sqlx to use the cached query metadata instead of a live database.
@@ -22,11 +18,11 @@ RUN cargo build --release -p solitaire_server
 FROM debian:bookworm-slim
 
 RUN apt-get update \
-    && apt-get install -y libssl3 ca-certificates \
+    && apt-get install -y ca-certificates \
     && rm -rf /var/lib/apt/lists/*
 
 COPY --from=builder /app/target/release/solitaire_server /usr/local/bin/solitaire_server
 
-EXPOSE 8080
+EXPOSE ${SERVER_PORT:-8080}
 
 ENTRYPOINT ["/usr/local/bin/solitaire_server"]

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 funman300
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,73 @@
+# Solitaire Quest
+
+A cross-platform Klondike Solitaire game written in Rust, featuring a full progression system with XP, levels, achievements, daily challenges, and optional self-hosted sync so your stats follow you across machines.
+
+## Features
+
+- **Klondike Solitaire** — Draw One and Draw Three modes
+- **Progression** — XP, levels, unlockable card backs and backgrounds
+- **18 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
+- **Special Modes** (unlocked at level 5): Zen, Time Attack, Challenge
+- **Sync** — pull/push stats across devices via a self-hosted server
+- **Color-blind mode** — blue tint on red-suit cards
+
+## Building
+
+**Prerequisites**
+
+- Rust stable toolchain (`rustup install stable`)
+- Linux: `libasound2-dev libudev-dev libxkbcommon-dev`
+- macOS: Xcode Command Line Tools
+
+```bash
+# Fast development build
+cargo run -p solitaire_app --features bevy/dynamic_linking
+
+# Release build
+cargo build -p solitaire_app --release
+./target/release/solitaire_app
+```
+
+## Controls
+
+| Key | Action |
+|---|---|
+| Left click / drag | Move cards |
+| Right click | Highlight legal moves for a card |
+| Space / D | Draw from stock |
+| Z / Ctrl+Z | Undo |
+| N | New game |
+| S | Stats overlay |
+| A | Achievements overlay |
+| P | Profile overlay |
+| O | Settings |
+| L | Leaderboard |
+| H | Help / controls |
+| Enter | Auto-complete (when badge is lit) |
+| Escape | Pause / clear selection |
+| Arrow keys | Navigate card selection |
+
+## Sync Server (optional)
+
+To sync stats across machines, run the self-hosted server. See [README_SERVER.md](README_SERVER.md) for setup instructions.
+
+Once the server is running, open **Settings → Sync Backend**, enter the server URL and your username, and register an account from within the game.
+
+## Running Tests
+
+```bash
+# All tests
+cargo test --workspace
+
+# Just game logic (no display required)
+cargo test -p solitaire_core -p solitaire_sync -p solitaire_data -p solitaire_server
+
+# Lint
+cargo clippy --workspace -- -D warnings
+```
+
+## License
+
+MIT — see [LICENSE](LICENSE).

docs/android_investigation.md

@@ -0,0 +1,247 @@
+# Android Port Investigation
+
+> **Date:** 2026-04-28  
+> **Author:** Claude Code  
+> **Scope:** Feasibility analysis for porting Solitaire Quest to Android using cargo-mobile2
+
+---
+
+## Summary
+
+A working Android port is feasible but not trivial. The core game logic (`solitaire_core`, `solitaire_sync`) compiles to Android without changes. Every other crate requires at least minor surgery. The biggest blockers are the `keyring` crate (no Android backend), the `kira`/`AudioManager` audio stack (`DefaultBackend` uses CPAL which targets desktop), and the `dirs` crate returning `None` on Android in its current usage. Touch input already has a solid foundation in `input_plugin.rs`. Estimated effort from a clean Android toolchain is **12–18 developer-days** to reach a playable-but-rough state.
+
+---
+
+## 1. Bevy on Android — Current Status
+
+Bevy's Android support is community-maintained via the `winit` backend and is usable but carries known rough edges as of the 0.15/0.16 generation.
+
+**What works:**
+- Basic rendering via Vulkan (through `wgpu`). OpenGL ES fallback is available for older devices.
+- Touch input events: Bevy's `TouchInput` events and the `Touches` resource are populated from Android `MotionEvent`s via `winit`. The existing `touch_start_drag`, `touch_follow_drag`, `touch_end_drag`, and `handle_touch_stock_tap` systems in `input_plugin.rs` will function correctly — this was already written with multi-touch in mind and uses `TouchPhase::Started/Moved/Ended/Canceled` cleanly.
+- Bevy UI (the `bevy::ui` module used for all overlays).
+- `WindowResized` events fire correctly, so the layout system will recompute for any screen size.
+
+**What does not work / needs attention:**
+- **`bevy/dynamic_linking`**: The dynamic linking feature must be stripped from any Android build profile. Dynamic linking is a desktop-only development shortcut; Android requires static linking.
+- **Fixed window size**: `main.rs` sets `resolution: (1280u32, 800u32)`. On Android the window is always the full display. This value is harmlessly overridden by the OS, but `min_width`/`min_height` constraints should be removed or set to 0 for Android to avoid Winit warnings.
+- **`F11` fullscreen toggle** (`handle_fullscreen` in `input_plugin.rs`): `WindowMode::BorderlessFullscreen` is desktop-only. On Android it should be a no-op.
+- **Keyboard shortcuts**: The entire `handle_keyboard_core`, `handle_keyboard_hint`, `handle_keyboard_forfeit` systems are desktop-only workflows. They will not crash, but they are dead code on Android. No touchscreen replacement for Undo (U), New Game (N), Draw (D/Space), Hint (H), Forfeit (G) exists yet — these need an on-screen UI.
+- **`CursorPlugin`**: The custom cursor sprite plugin is irrelevant on Android (no cursor). Harmless to leave registered, but it uses `PrimaryWindow` cursor APIs that may panic or warn on Android.
+
+**cargo-mobile2 integration for Bevy:**
+The standard path is:
+1. Install `cargo-mobile2`: `cargo install --locked cargo-mobile2`
+2. Run `cargo mobile init` in the workspace root. This generates an `android/` directory with the Gradle project, `AndroidManifest.xml`, and JNI glue.
+3. cargo-mobile2 targets the `solitaire_app` binary crate (the thin entry point). The generated `lib.rs` shim calls `android_main` via `bevy::winit`'s Android entry point.
+4. The `solitaire_app` crate needs a `[lib]` target added alongside the existing `[[bin]]`, with `crate-type = ["cdylib"]`, used only when building for Android.
+
+**Required `Cargo.toml` changes (workspace level):**
+```toml
+[target.'cfg(target_os = "android")'.dependencies]
+# android_logger and ndk-glue wiring are handled by cargo-mobile2's generated shim.
+# No direct ndk-glue dependency is needed in app code when using Bevy + cargo-mobile2.
+```
+
+**NDK version:** Android NDK r25c or r26 LTS is the tested range for `wgpu`/Vulkan on Android. NDK r27+ may work but has had compatibility reports with CPAL. Set `ANDROID_NDK_ROOT` to the NDK root; the minimum API level should be 26 (Android 8.0) for Vulkan stability.
+
+---
+
+## 2. Audio — `kira` + `DefaultBackend`
+
+**The problem:**  
+`solitaire_engine/src/audio_plugin.rs` creates an `AudioManager<DefaultBackend>`. `kira`'s `DefaultBackend` is an alias for `CpalBackend`, which wraps CPAL. CPAL's Android backend uses OpenSL ES and is functional but historically fragile. As of kira 0.9+, `kira` no longer bundles its own CPAL backend by default in the same way — the `DefaultBackend` feature must be enabled explicitly and requires `cpal` with the Android feature.
+
+**Current code behavior:**  
+The `AudioPlugin::build` already handles the "no audio device" case gracefully:
+```rust
+let mut manager = AudioManager::<DefaultBackend>::new(AudioManagerSettings::default()).ok();
+if manager.is_none() {
+    warn!("audio device unavailable; SFX disabled");
+}
+```
+This means if the audio manager fails to initialise on Android, the game continues silently. This is acceptable as a first-pass fallback.
+
+**What is needed for working audio on Android:**
+- Add `kira` dependency with `cpal` backend enabled for Android: The `kira` workspace dependency currently specifies `version = "0.12"`. Verify that `kira/Cargo.toml` exposes a `cpal` feature (or that `DefaultBackend` compiles on Android targets with NDK). If not, a `CpalBackend` with `cpal = { features = ["oboe"] }` may be needed.
+- The `NonSend` resource `AudioState` should compile fine — `NonSend` is legal in Bevy Android builds.
+- `include_bytes!` for the WAV assets is compile-time and unaffected by platform.
+
+**Recommendation:** Defer full audio verification to a device test. The graceful fallback means a silent-but-working first build is achievable without resolving this.
+
+---
+
+## 3. `keyring` Crate — No Android Backend
+
+**The problem:**  
+`keyring = "2"` is used in `solitaire_data/src/auth_tokens.rs` to store JWT access and refresh tokens in the OS keychain. The `keyring` crate's Android backend does not exist — as of v2.x, supported backends are: macOS Keychain, Windows Credential Manager, Linux Secret Service (D-Bus), and iOS Keychain. There is no Android KeyStore backend.
+
+On Android, `Entry::new(...)` will return `keyring::Error::NoStorageAccess`, which the existing code already maps to `TokenError::KeychainUnavailable`. So the code will not crash — it will simply fail every token store/load operation.
+
+**Current failure mode:**  
+Every call to `store_tokens`, `load_access_token`, `load_refresh_token`, or `delete_tokens` will return `Err(TokenError::KeychainUnavailable(...))`. The sync client in `sync_client.rs` needs to be verified to handle this gracefully rather than propagating an error that disables sync entirely.
+
+**Options for Android credential storage:**
+
+| Option | Security | Effort | Notes |
+|---|---|---|---|
+| **In-memory only (prompt re-login each session)** | N/A | 1 day | Simplest. On `TokenError::KeychainUnavailable`, the `SyncProvider` returns `SyncError::Auth`, user is prompted to log in. Already architecturally supported. |
+| **Encrypted `SharedPreferences` equivalent via JNI** | Good | 4–6 days | Call Android's `EncryptedSharedPreferences` (Jetpack Security) via JNI. Significant JNI boilerplate. |
+| **AES-256 file encryption using Android Keystore via JNI** | Excellent | 5–8 days | Proper Android keychain equivalent. Complex JNI. |
+| **Store in app-private file, unencrypted** | Poor | 0.5 days | Only acceptable during development. Never ship. |
+
+**Recommended approach (first pass):** Use the in-memory / re-login-each-session path. The existing `TokenError::KeychainUnavailable` variant already exists for exactly this reason (Linux without a running secret service). The `SyncPlugin` should detect this on startup and present a "Sync unavailable — please log in" message rather than a hard error. This requires:
+1. Conditional compilation: when `cfg(target_os = "android")`, replace the `keyring` calls with a no-op in-memory store (a simple `Mutex<HashMap<String, String>>`).
+2. A `#[cfg(not(target_os = "android"))]` guard on the `keyring` import/dependency in `solitaire_data/Cargo.toml`.
+
+**Required `solitaire_data/Cargo.toml` change:**
+```toml
+[target.'cfg(not(target_os = "android"))'.dependencies]
+keyring = { workspace = true }
+
+[target.'cfg(target_os = "android")'.dependencies]
+# keyring is replaced by in-memory storage; no dependency needed
+```
+
+---
+
+## 4. `dirs` Crate — Data Directory on Android
+
+**The problem:**  
+`storage.rs` and other persistence modules use `dirs::data_dir()` to locate `~/.local/share/solitaire_quest/` (or platform equivalent). On Android, `dirs::data_dir()` returns `None` because there is no `XDG_DATA_HOME` and the `dirs` crate does not implement an Android-specific path.
+
+**Current code behavior:**  
+All persistence functions already handle `None` gracefully (returning default values or `Err`), consistent with the CLAUDE.md lesson about `dirs::data_dir()`. Stats and progress will silently not persist across sessions if `data_dir()` returns `None`.
+
+**Fix required:**  
+Android apps should store private data in the app's internal storage directory, obtained via JNI: `context.getFilesDir()`. This requires either:
+- A thin JNI helper (via `jni` crate) called once on startup to obtain the path and store it as a global.
+- Or passing the path in via the `android_main` entry point using `cargo-mobile2`'s `AndroidApp` handle, which exposes `internal_data_path()`.
+
+The `cargo-mobile2` + Bevy path exposes an `AndroidApp` via `bevy::winit`'s Android entry point. Bevy 0.13+ passes `AndroidApp` through `WinitPlugin`, and it is accessible via a Bevy resource. A startup system can extract `app.internal_data_path()` and insert a `PlatformDataDirResource` that the storage functions read instead of calling `dirs::data_dir()`.
+
+**Effort:** 1–2 days to implement the override and thread it through all `storage.rs` / `progress.rs` / `settings.rs` / `achievements.rs` call sites.
+
+---
+
+## 5. Touch Input — Current State and Gaps
+
+**What already exists (strong foundation):**
+
+The `InputPlugin` in `input_plugin.rs` has a complete parallel touch pipeline:
+
+| System | Purpose | Status |
+|---|---|---|
+| `handle_touch_stock_tap` | Tap the stock pile to draw | Complete |
+| `touch_start_drag` | Begin a touch drag on a face-up card | Complete |
+| `touch_follow_drag` | Move card(s) with the active finger | Complete |
+| `touch_end_drag` | Resolve the drag (move or reject) | Complete |
+
+The touch systems use `TouchInput` events and the `Touches` resource, map touch IDs to `DragState.active_touch_id` to prevent multi-finger conflicts, and share the same `DragState`, `MoveRequestEvent`, `MoveRejectedEvent`, and `StateChangedEvent` infrastructure as the mouse pipeline. The drag threshold (`tuning.drag_threshold_px`) applies identically.
+
+**Gaps for a production Android experience:**
+
+1. **No double-tap equivalent for auto-move**: `handle_double_click` is mouse-only. Android users need a double-tap to trigger the same "move to best destination" logic. The `handle_double_click` system checks `buttons.just_pressed(MouseButton::Left)` and will be inert on Android. Estimated: 1 day.
+
+2. **No touch equivalent for keyboard actions**: Undo, New Game, Draw (when stock is visible but tapping it is awkward), Hint, and Forfeit have no on-screen buttons. These need an Android-specific UI bar or gesture (e.g. two-finger tap for undo). Estimated: 2–3 days for a minimal floating action button strip.
+
+3. **Drag threshold tuning**: The threshold is in `AnimationTuning` (`tuning.drag_threshold_px`). Touch screens typically need a larger threshold than mouse (physical screens have more accidental movement during a tap). The current value should be evaluated on a real device and likely increased for touch.
+
+4. **No long-press for right-click equivalent**: The right-click highlight/hint glow (`HintHighlightTimer`) is triggered via right mouse button. Long-press detection is not yet implemented. This is a missing feature but not a blocker for basic play.
+
+5. **`handle_double_click` uses `LocalDateTime`-based timing via `Time`**: This will work on Android, but `DOUBLE_CLICK_WINDOW = 0.35s` may feel too tight on touch. Should be configurable.
+
+---
+
+## 6. Additional Issues Not in Scope of the Four Research Areas
+
+**`CursorPlugin`:** Uses Bevy's cursor APIs which are desktop-only. Should be conditionally compiled out on Android with `#[cfg(not(target_os = "android"))]`.
+
+**`reqwest` with `rustls-native-certs`:** The `reqwest` dependency uses `rustls` with native root certificates. On Android, `rustls-native-certs` reads system certificates differently (via the `android_system_properties` crate internally). This generally works but should be tested; Android's certificate store is in a non-standard location vs Linux.
+
+**App lifecycle (suspend/resume):** Android can suspend the process at any time. Bevy handles `WindowEvent::Suspended` and `WindowEvent::Resumed` via `winit`, pausing the render loop. The `SyncPlugin`'s "push on exit" path (`AppExit` event) should also trigger on `WindowEvent::Suspended` to avoid data loss when the user backgrounds the app. This is a separate feature (1 day).
+
+**No `sqlx` on Android:** `solitaire_server` is a server binary and is never built for Android. The `sqlx` dependency only exists in `solitaire_server/Cargo.toml` and will not affect Android builds of the client crates.
+
+**`solitaire_assetgen`:** The asset generation tool is desktop-only and not part of the client build. Unaffected.
+
+---
+
+## 7. Required Changes Per Crate
+
+### `solitaire_core` and `solitaire_sync`
+No changes required. Both are pure Rust with no platform dependencies.
+
+### `solitaire_data`
+| Change | Effort |
+|---|---|
+| Gate `keyring` dependency on `#[cfg(not(target_os = "android"))]` | 0.5 days |
+| Implement `auth_tokens.rs` in-memory fallback for Android | 1 day |
+| Add `internal_data_path()` override for `dirs::data_dir()` on Android | 1.5 days |
+| Audit all `dirs::data_dir()` / `settings_file_path()` call sites to accept injected path | 0.5 days |
+
+### `solitaire_engine`
+| Change | Effort |
+|---|---|
+| Conditionally disable `CursorPlugin` on Android | 0.5 days |
+| Disable `handle_fullscreen` on Android (or make it a no-op) | 0.25 days |
+| Implement double-tap for auto-move (touch equivalent of `handle_double_click`) | 1 day |
+| On-screen action bar for Undo, New Game, Hint (minimal floating buttons) | 2.5 days |
+| Tune drag threshold for touch; expose as a platform-specific tuning constant | 0.5 days |
+| Trigger sync push on `WindowEvent::Suspended` in `SyncPlugin` | 1 day |
+| Verify `kira` audio on Android (test `DefaultBackend` / CPAL; implement fallback if needed) | 1–2 days |
+
+### `solitaire_app`
+| Change | Effort |
+|---|---|
+| Add `[lib]` target with `crate-type = ["cdylib"]` for Android builds | 0.25 days |
+| Create `src/lib.rs` (or `src/android.rs`) Android entry point calling `android_main` | 0.5 days |
+| Remove or guard fixed `resolution` / `resize_constraints` for Android | 0.25 days |
+| Pass `AndroidApp::internal_data_path()` to a startup resource | 0.5 days |
+
+### Build / Toolchain
+| Change | Effort |
+|---|---|
+| Install cargo-mobile2, Android NDK r25c/r26, `aarch64-linux-android` target | 1 day |
+| Run `cargo mobile init`, configure `android/` Gradle project | 0.5 days |
+| Get a first build compiling (resolve linker / NDK issues) | 1–2 days |
+
+---
+
+## 8. Estimated Effort
+
+| Phase | Description | Days |
+|---|---|---|
+| Toolchain setup | NDK, cargo-mobile2, first compile | 2–3 |
+| `solitaire_data` Android adaptations | keyring fallback, data dir | 3 |
+| `solitaire_app` Android entry point | cdylib, AndroidApp wiring | 1 |
+| `solitaire_engine` guards and fixes | cursor, fullscreen, audio verify | 2–3 |
+| Touch UX improvements | double-tap, action bar, threshold tuning | 4–5 |
+| Testing on real device / emulator | iteration, lifecycle edge cases | 2–3 |
+| **Total** | | **14–17 days** |
+
+This produces a playable, functionally complete Android build. It does not include Play Store preparation (signing keys, metadata, icon set, permissions manifest tuning) which would add 1–2 more days.
+
+---
+
+## 9. Recommended First Step
+
+**Get the workspace to compile for `aarch64-linux-android` without running.**
+
+This surfaces all the real linker and dependency errors before writing any gameplay code:
+
+```bash
+# Install toolchain
+rustup target add aarch64-linux-android
+cargo install --locked cargo-mobile2
+
+# In the workspace root:
+cargo mobile init   # generates android/ directory
+
+# Attempt a library build targeting Android
+cargo build -p solitaire_app --target aarch64-linux-android 2>&1 | head -60
+```
+
+The first build will fail on `keyring` (no Android backend) and likely on `dirs`. Fixing those two in `solitaire_data` — gate `keyring` behind `cfg(not(target_os = "android"))` and stub the data directory — will probably get the workspace to a clean compile. From there, the path to a running APK is incremental.
+
+Do not attempt to resolve audio or touch UX until the build compiles cleanly. Compile errors are the only true blockers; the rest are feature gaps.

docs/sync_test_runbook.md

@@ -0,0 +1,318 @@
+# Sync Subsystem Manual Test Runbook
+
+**Version:** 1.0  
+**Last Updated:** 2026-04-28  
+**Scope:** Cross-machine sync, JWT refresh, conflict resolution, account deletion
+
+---
+
+## Prerequisites
+
+### Infrastructure
+
+- Two machines (or VMs) referred to as **Machine A** and **Machine B** throughout this runbook. Both must be able to reach the sync server over the network.
+- A running Solitaire Quest sync server reachable at a known URL, e.g. `https://solitaire.example.com`. See `README_SERVER.md` for setup.
+- Verify the server is live before starting:
+
+  ```bash
+  curl -s https://solitaire.example.com/health
+  # Expected: {"status":"ok","version":"..."}
+  ```
+
+### Accounts
+
+- You will register two separate accounts (`alice` and `bob`) during the tests. You do not need to create them in advance.
+
+### Tooling
+
+- `curl` or a REST client (Insomnia/Postman) for manual API calls.
+- `sqlite3` CLI if you need to inspect the server database directly.
+- The game binary built in release mode on both machines:
+
+  ```bash
+  cargo build -p solitaire_app --release
+  ```
+
+### Baseline: Clear local data on both machines
+
+Before starting, delete any existing local save files to ensure a clean state:
+
+```
+# Linux
+rm -rf ~/.local/share/solitaire_quest/
+
+# macOS
+rm -rf ~/Library/Application\ Support/solitaire_quest/
+
+# Windows
+rmdir /s %APPDATA%\solitaire_quest\
+```
+
+---
+
+## Test 1 — Full Sync Round-Trip (register, play, push, verify on second machine)
+
+**Goal:** Confirm that stats played on Machine A appear on Machine B after sync.
+
+### Step 1 — Register on Machine A
+
+1. Launch the game on Machine A.
+2. Open **Settings** (key: `O`) and locate the **Sync** section.
+3. Enter the server URL and choose a username: `alice`.
+4. Choose a password (at least 12 characters).
+5. Tap **Register** (or **Login** if the account already exists).
+6. The Settings screen should show **Status: syncing…** briefly, then **Status: last synced at HH:MM**.
+7. Close the game.
+
+Verify the registration succeeded directly:
+
+```bash
+curl -s -X POST https://solitaire.example.com/api/auth/login \
+  -H "Content-Type: application/json" \
+  -d '{"username":"alice","password":"<your-password>"}' | jq .
+# Expected: {"access_token":"...","refresh_token":"..."}
+```
+
+### Step 2 — Play games on Machine A
+
+1. Launch the game on Machine A.
+2. Win at least **three games** (Draw One or Draw Three — note which mode).
+3. Check the Stats overlay (key: `S`) and note:
+   - `games_played`
+   - `games_won`
+   - `win_streak_current`
+   - `fastest_win_seconds`
+4. Close the game normally (this triggers the push-on-exit path).
+
+### Step 3 — Verify the push reached the server
+
+```bash
+# Log in to get a fresh token
+TOKEN=$(curl -s -X POST https://solitaire.example.com/api/auth/login \
+  -H "Content-Type: application/json" \
+  -d '{"username":"alice","password":"<your-password>"}' | jq -r .access_token)
+
+# Pull the server's stored state
+curl -s -H "Authorization: Bearer $TOKEN" \
+  https://solitaire.example.com/api/sync/pull | jq .merged.stats
+```
+
+Confirm `games_won` matches what you recorded in Step 2.
+
+### Step 4 — Pull on Machine B
+
+1. Launch the game on **Machine B** (clean local data).
+2. Open **Settings**, enter the same server URL, and log in as `alice` with the same password.
+3. The plugin will pull on startup. Wait for **Status: last synced at HH:MM**.
+4. Open the Stats overlay (key: `S`) and confirm the numbers from Step 2 are present.
+
+**Pass criterion:** `games_won`, `games_played`, and `fastest_win_seconds` on Machine B match Machine A.
+
+---
+
+## Test 2 — JWT Refresh on 401
+
+**Goal:** Confirm that an expired access token is refreshed transparently without user interaction.
+
+### Step 1 — Shorten the access token TTL on the server (test environment only)
+
+Edit the server `.env` and set a short expiry, then restart:
+
+```
+JWT_ACCESS_EXPIRY_SECS=5
+```
+
+> If you cannot modify the server config, skip to the manual token corruption method in Step 1b.
+
+### Step 1b (alternative) — Corrupt the stored access token directly
+
+On the machine where you want to test (Linux example):
+
+```bash
+# List keychain entries (uses secret-tool on GNOME)
+secret-tool search service solitaire_quest_server
+
+# Overwrite alice's access token with a deliberately invalid value
+secret-tool store --label="alice_access" service solitaire_quest_server account alice_access <<< "invalid.token.value"
+```
+
+### Step 2 — Trigger a sync with the expired/invalid token
+
+1. Launch the game.
+2. Either wait for the startup pull (for the short-TTL method), or open **Settings** and tap **Sync Now**.
+3. Observe the **Status** field.
+
+**Pass criterion (transparent refresh):** Status briefly shows "syncing…" and then shows "last synced at HH:MM" — no auth error is displayed. The access token in the keychain has been silently replaced.
+
+**Verify the new token is valid:**
+
+```bash
+# Extract the new token from the keychain
+secret-tool lookup service solitaire_quest_server account alice_access | head -c 50
+# Should look like a valid JWT (three base64 segments separated by dots)
+```
+
+### Step 3 — Test failed refresh (both tokens expired)
+
+1. Corrupt both the access token and the refresh token in the keychain:
+
+   ```bash
+   secret-tool store --label="alice_access" service solitaire_quest_server account alice_access <<< "bad"
+   secret-tool store --label="alice_refresh" service solitaire_quest_server account alice_refresh <<< "bad"
+   ```
+
+2. Launch the game and trigger a sync.
+
+**Pass criterion:** The Settings screen shows an error message matching: "Login expired — tap Sync Now after re-logging in". The game must not crash. No data must be lost (local files are untouched).
+
+3. Restore: log in again via Settings to get fresh tokens.
+
+---
+
+## Test 3 — Conflict Scenario (offline play on both machines, then sync)
+
+**Goal:** Confirm that progress made on both devices offline is merged correctly, with no data silently discarded.
+
+### Step 1 — Take both machines offline
+
+Disable network on both Machine A and Machine B (e.g. airplane mode, or block the server URL in `/etc/hosts`).
+
+### Step 2 — Play on Machine A (offline)
+
+1. Win 5 games. Note the resulting streak and `games_won`.
+2. Close the game.
+
+### Step 3 — Play on Machine B (offline)
+
+1. Win 3 different games. Note the resulting streak and `games_won`.
+2. Close the game.
+
+At this point Machine A and Machine B have divergent state.
+
+### Step 4 — Re-enable network, sync Machine A first
+
+1. Restore network.
+2. Launch the game on Machine A. The push-on-exit from Step 2 did not reach the server, so:
+   - Open Settings, tap **Sync Now** to force a pull.
+   - Close the game (triggers push-on-exit).
+3. Verify the server has Machine A's state:
+
+   ```bash
+   curl -s -H "Authorization: Bearer $TOKEN" \
+     https://solitaire.example.com/api/sync/pull | jq '.merged.stats.games_won'
+   ```
+
+### Step 5 — Sync Machine B
+
+1. Launch the game on Machine B.
+2. The startup pull fetches the server's merged state (which now contains Machine A's wins).
+3. Open Settings — wait for **Status: last synced at HH:MM**.
+4. Open the Stats overlay.
+
+**Pass criteria:**
+- `games_won` = max(Machine A wins, Machine B wins) — at minimum the higher of the two counts.
+- No games are lost — both machines' win counts contribute.
+- If the two machines had different `win_streak_current` values, a conflict should be recorded (visible if you inspect the server response directly):
+
+  ```bash
+  curl -s -H "Authorization: Bearer $TOKEN" \
+    https://solitaire.example.com/api/sync/pull | jq '.conflicts'
+  ```
+
+- The `win_streak_current` conflict entry will show `local_value` and `remote_value`. The higher value is used as the best-effort resolution.
+
+---
+
+## Test 4 — Account Deletion
+
+**Goal:** Confirm that `DELETE /api/account` removes all server-side data and that a subsequent authenticated request is rejected.
+
+### Step 1 — Confirm data exists before deletion
+
+```bash
+curl -s -H "Authorization: Bearer $TOKEN" \
+  https://solitaire.example.com/api/sync/pull | jq '.merged.stats.games_played'
+# Expected: a non-zero number
+```
+
+### Step 2 — Delete the account via the API
+
+```bash
+curl -s -X DELETE \
+  -H "Authorization: Bearer $TOKEN" \
+  https://solitaire.example.com/api/account | jq .
+# Expected: {"ok":true}
+```
+
+### Step 3 — Verify all data is gone from the server
+
+```bash
+# Try to pull with the (now-invalid) token
+curl -s -H "Authorization: Bearer $TOKEN" \
+  https://solitaire.example.com/api/sync/pull
+# Expected: HTTP 401 Unauthorized
+
+# Try to log in again with the same credentials
+curl -s -X POST https://solitaire.example.com/api/auth/login \
+  -H "Content-Type: application/json" \
+  -d '{"username":"alice","password":"<your-password>"}' | jq .
+# Expected: HTTP 401 or error body indicating invalid credentials
+```
+
+### Step 4 — Verify local data is NOT deleted
+
+1. Open the game. The local files (`stats.json`, `progress.json`, etc.) must still be present and intact — account deletion only affects the server.
+2. Check the Stats overlay and confirm local game history is visible.
+3. The Settings screen may show an auth error on next sync attempt, which is expected.
+
+### Step 5 — Re-register with the same username (optional)
+
+```bash
+curl -s -X POST https://solitaire.example.com/api/auth/register \
+  -H "Content-Type: application/json" \
+  -d '{"username":"alice","password":"<new-password>"}' | jq .
+# Expected: {"access_token":"...","refresh_token":"..."} — fresh empty account
+```
+
+**Pass criterion:** Re-registration succeeds, and a subsequent pull returns a payload with all-zero stats (completely fresh account, no residual data from the deleted account).
+
+---
+
+## Test 5 — Server Errors Do Not Show "Login Expired"
+
+**Goal:** Verify that a 500 Internal Server Error or 429 Too Many Requests shows a network error, not an auth error, to the user.
+
+### Step 1 — Simulate a 500 with a reverse proxy rule
+
+Add a temporary nginx/Caddy rule to return 500 for `/api/sync/*`:
+
+```nginx
+location /api/sync/ {
+    return 500;
+}
+```
+
+Or use a local proxy like `mitmproxy` to intercept and rewrite responses.
+
+### Step 2 — Trigger a sync
+
+Open Settings and tap **Sync Now**.
+
+**Pass criterion:** The Status field shows "Can't reach server — check your connection" (network error message), NOT "Login expired — tap Sync Now after re-logging in" (auth error message).
+
+Remove the nginx rule after this test.
+
+---
+
+## Regression Checklist
+
+After running all tests above, confirm:
+
+- [ ] No crash occurred during any test on either machine.
+- [ ] Local save files (`stats.json`, `progress.json`, `achievements.json`) are present and valid JSON after all tests.
+- [ ] The game launches and plays normally after all sync operations (sync is additive — never blocks gameplay).
+- [ ] The Stats overlay shows correct numbers on both machines after a successful sync round-trip.
+- [ ] An expired token is refreshed transparently without the user having to log in again.
+- [ ] A doubly-expired token surfaces a clear error message to the user.
+- [ ] Account deletion removes all server data; local data is preserved.
+- [ ] HTTP 5xx and 429 responses show a network error, not an auth error.

pkg/solitaire-quest-server/PKGBUILD

@@ -0,0 +1,63 @@
+# Maintainer: funman300 <funman300@gmail.com>
+
+pkgname=solitaire-quest-server
+pkgver=0.1.0
+pkgrel=1
+pkgdesc='Self-hosted sync server for Solitaire Quest (stats, achievements, leaderboards)'
+url='https://github.com/funman300/solitaire-quest'
+license=('MIT')
+arch=('x86_64')
+makedepends=('cargo' 'rust')
+depends=(
+    'gcc-libs'
+    'glibc'
+)
+backup=('etc/solitaire-quest-server/server.env')
+
+# Build from the local workspace (two levels above this PKGBUILD).
+_srcdir="$startdir/../.."
+source=(
+    'solitaire-quest-server.service'
+    'server.env'
+)
+b2sums=('SKIP'
+        'SKIP')
+
+prepare() {
+    export RUSTUP_TOOLCHAIN=stable
+    cd "$_srcdir"
+    cargo fetch --locked --target "$(rustc -Vv | grep host | cut -d' ' -f2)"
+}
+
+build() {
+    export RUSTUP_TOOLCHAIN=stable
+    export CARGO_TARGET_DIR=target
+    cd "$_srcdir"
+    cargo build --frozen --release -p solitaire_server
+}
+
+check() {
+    export RUSTUP_TOOLCHAIN=stable
+    cd "$_srcdir"
+    cargo test --frozen -p solitaire_server -p solitaire_sync
+}
+
+package() {
+    cd "$_srcdir"
+
+    # Binary
+    install -Dm0755 -t "$pkgdir/usr/bin/" "target/release/solitaire_server"
+
+    # systemd service
+    install -Dm0644 "$srcdir/solitaire-quest-server.service" \
+        "$pkgdir/usr/lib/systemd/system/solitaire-quest-server.service"
+
+    # Environment file (contains JWT_SECRET, DATABASE_URL, SERVER_PORT)
+    install -Dm0640 "$srcdir/server.env" \
+        "$pkgdir/etc/solitaire-quest-server/server.env"
+
+    # License and docs
+    install -Dm0644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+    install -Dm0644 README_SERVER.md \
+        "$pkgdir/usr/share/doc/$pkgname/README_SERVER.md"
+}

pkg/solitaire-quest-server/server.env

@@ -0,0 +1,15 @@
+# Solitaire Quest Server — environment configuration
+# This file is installed to /etc/solitaire-quest-server/server.env (mode 0640).
+# Edit these values before starting the service.
+
+# Path to the SQLite database file.
+# The directory must be writable by the solitaire-quest service user.
+DATABASE_URL=sqlite:///var/lib/solitaire-quest-server/solitaire.db
+
+# HS256 signing secret for JWT tokens.
+# Generate a strong secret with: openssl rand -hex 32
+# REQUIRED — server will refuse to start if unset.
+JWT_SECRET=changeme_generate_with_openssl_rand_hex_32
+
+# TCP port the server listens on.
+SERVER_PORT=8080

pkg/solitaire-quest-server/solitaire-quest-server.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=Solitaire Quest Sync Server
+Documentation=https://github.com/funman300/solitaire-quest/blob/main/README_SERVER.md
+After=network.target
+
+[Service]
+Type=simple
+User=solitaire-quest
+Group=solitaire-quest
+EnvironmentFile=/etc/solitaire-quest-server/server.env
+ExecStart=/usr/bin/solitaire_server
+Restart=on-failure
+RestartSec=5s
+
+# Harden the service
+NoNewPrivileges=true
+PrivateTmp=true
+ProtectSystem=strict
+ProtectHome=true
+ReadWritePaths=/var/lib/solitaire-quest-server
+
+[Install]
+WantedBy=multi-user.target

pkg/solitaire-quest/PKGBUILD

@@ -0,0 +1,48 @@
+# Maintainer: funman300 <funman300@gmail.com>
+
+pkgname=solitaire-quest
+pkgver=0.1.0
+pkgrel=1
+pkgdesc='Cross-platform Klondike Solitaire with progression, achievements, and optional sync'
+url='https://github.com/funman300/solitaire-quest'
+license=('MIT')
+arch=('x86_64')
+makedepends=('cargo' 'rust')
+depends=(
+    'gcc-libs'
+    'glibc'
+    'alsa-lib'
+    'libxkbcommon'
+    'systemd-libs'   # libudev.so — required by Bevy input
+)
+
+# Build from the local workspace (two levels above this PKGBUILD).
+_srcdir="$startdir/../.."
+source=()
+b2sums=()
+
+prepare() {
+    export RUSTUP_TOOLCHAIN=stable
+    cd "$_srcdir"
+    cargo fetch --locked --target "$(rustc -Vv | grep host | cut -d' ' -f2)"
+}
+
+build() {
+    export RUSTUP_TOOLCHAIN=stable
+    export CARGO_TARGET_DIR=target
+    cd "$_srcdir"
+    cargo build --frozen --release -p solitaire_app
+}
+
+check() {
+    export RUSTUP_TOOLCHAIN=stable
+    cd "$_srcdir"
+    # Only test non-Bevy crates — Bevy integration tests require a GPU/display.
+    cargo test --frozen -p solitaire_core -p solitaire_sync
+}
+
+package() {
+    cd "$_srcdir"
+    install -Dm0755 -t "$pkgdir/usr/bin/" "target/release/solitaire_app"
+    install -Dm0644 LICENSE "$pkgdir/usr/share/licenses/$pkgname/LICENSE"
+}

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "stable"

solitaire_app/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name    = "solitaire_app"
 version.workspace = true
+license.workspace = true
 edition.workspace = true
 
 [[bin]]
@@ -11,3 +12,4 @@ path = "src/main.rs"
 bevy             = { workspace = true }
 solitaire_engine = { workspace = true }
 solitaire_data   = { workspace = true }
+keyring          = { workspace = true }

solitaire_app/src/main.rs

@@ -1,14 +1,26 @@
 use bevy::prelude::*;
 use solitaire_data::{load_settings_from, provider_for_backend, settings_file_path, Settings};
 use solitaire_engine::{
-    AchievementPlugin, AnimationPlugin, AudioPlugin, AutoCompletePlugin, CardPlugin,
+    AchievementPlugin, AnimationPlugin, AudioPlugin, AutoCompletePlugin, CardAnimationPlugin,
-    ChallengePlugin, CursorPlugin, DailyChallengePlugin, FeedbackAnimPlugin, GamePlugin,
+    CardPlugin, ChallengePlugin, CursorPlugin, DailyChallengePlugin, FeedbackAnimPlugin,
-    HelpPlugin, HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin, OnboardingPlugin,
+    FontPlugin, GamePlugin, HelpPlugin, HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin,
-    PausePlugin, ProfilePlugin, ProgressPlugin, SettingsPlugin, StatsPlugin, SyncPlugin,
+    OnboardingPlugin, PausePlugin, ProfilePlugin, ProgressPlugin, SelectionPlugin, SettingsPlugin,
-    TablePlugin, TimeAttackPlugin, WeeklyGoalsPlugin,
+    StatsPlugin, SyncPlugin, TablePlugin, TimeAttackPlugin, WeeklyGoalsPlugin, WinSummaryPlugin,
 };
 
 fn main() {
+    // Initialise the platform keyring store before any token operations.
+    // On Linux this uses the Secret Service (GNOME Keyring / KWallet); on
+    // macOS it uses the Keychain; on Windows it uses the Credential store.
+    // If the platform has no OS keyring (e.g. a headless CI box), keyring
+    // operations will fail gracefully with TokenError::KeychainUnavailable.
+    if let Err(e) = keyring::use_native_store(true) {
+        eprintln!(
+            "warn: could not initialise OS keyring ({e}); \
+             server sync login will be unavailable"
+        );
+    }
+
     // Load settings before building the app so we can construct the right
     // sync provider. Falls back to defaults if no settings file exists yet.
     let settings: Settings = settings_file_path()
@@ -21,19 +33,27 @@ fn main() {
             DefaultPlugins.set(WindowPlugin {
                 primary_window: Some(Window {
                     title: "Solitaire Quest".into(),
-                    resolution: (1280.0, 800.0).into(),
+                    resolution: (1280u32, 800u32).into(),
+                    resize_constraints: bevy::window::WindowResizeConstraints {
+                        min_width: 800.0,
+                        min_height: 600.0,
+                        ..default()
+                    },
                     ..default()
                 }),
                 ..default()
             }),
         )
+        .add_plugins(FontPlugin)
         .add_plugins(GamePlugin)
         .add_plugins(TablePlugin)
         .add_plugins(CardPlugin)
         .add_plugins(CursorPlugin)
         .add_plugins(InputPlugin)
+        .add_plugins(SelectionPlugin)
         .add_plugins(AnimationPlugin)
         .add_plugins(FeedbackAnimPlugin)
+        .add_plugins(CardAnimationPlugin)
         .add_plugins(AutoCompletePlugin)
         .add_plugins(StatsPlugin::default())
         .add_plugins(ProgressPlugin::default())
@@ -52,5 +72,6 @@ fn main() {
         .add_plugins(OnboardingPlugin)
         .add_plugins(SyncPlugin::new(sync_provider))
         .add_plugins(LeaderboardPlugin)
+        .add_plugins(WinSummaryPlugin)
         .run();
 }

solitaire_assetgen/Cargo.toml

@@ -1,12 +1,22 @@
 [package]
 name = "solitaire_assetgen"
 version.workspace = true
+license.workspace = true
 edition.workspace = true
 publish = false
 
-# Dev-only utility: synthesizes placeholder SFX WAV files into `assets/audio/`.
+# Dev-only utility: synthesizes placeholder SFX WAV files into `assets/audio/`
+# and placeholder PNG images into `assets/cards/` and `assets/backgrounds/`.
 # Not depended on by any other workspace crate.
 
+[dependencies]
+png     = "0.17"
+ab_glyph = "0.2"
+
 [[bin]]
 name = "gen_sfx"
 path = "src/bin/gen_sfx.rs"
+
+[[bin]]
+name = "gen_art"
+path = "src/bin/gen_art.rs"

solitaire_assetgen/src/bin/gen_art.rs

@@ -0,0 +1,713 @@
+//! Generates PNG assets for Solitaire Quest.
+//!
+//! Produces:
+//! - 52 card face PNGs (120×168) — one per card, with rank, suit symbol, and
+//!   pip or face-letter layout baked in.
+//! - 5 card back PNGs (120×168) with distinctive coloured patterns.
+//! - 5 background PNGs (120×168) with textured felt/wood patterns.
+//!
+//! Run with: `cargo run -p solitaire_assetgen --bin gen_art`
+
+use ab_glyph::{Font, FontRef, PxScale, ScaleFont};
+use std::fs::File;
+use std::io::BufWriter;
+use std::path::Path;
+
+// ---------------------------------------------------------------------------
+// Card dimensions and palette
+// ---------------------------------------------------------------------------
+
+const W: u32 = 120;
+const H: u32 = 168;
+
+const BG: [u8; 4] = [0xFE, 0xFE, 0xF2, 0xFF];
+const BORDER: [u8; 4] = [0x99, 0x99, 0x99, 0xFF];
+const RED: [u8; 4] = [0xCC, 0x11, 0x11, 0xFF];
+const DARK: [u8; 4] = [0x11, 0x11, 0x11, 0xFF];
+
+fn suit_color(suit: u8) -> [u8; 4] {
+    if suit == 1 || suit == 2 { RED } else { DARK }
+}
+
+fn rank_str(rank: u8) -> &'static str {
+    ["A","2","3","4","5","6","7","8","9","10","J","Q","K"][rank as usize]
+}
+
+// ---------------------------------------------------------------------------
+// Pixel canvas (120×168 RGBA)
+// ---------------------------------------------------------------------------
+
+struct Canvas {
+    data: Vec<u8>,
+}
+
+impl Canvas {
+    fn new() -> Self {
+        let mut data = vec![0u8; (W * H * 4) as usize];
+        for i in 0..(W * H) as usize {
+            data[i * 4..i * 4 + 4].copy_from_slice(&BG);
+        }
+        Self { data }
+    }
+
+    /// Fill every pixel with a solid colour, erasing whatever was there before.
+    fn fill_solid(&mut self, c: [u8; 4]) {
+        for i in 0..(W * H) as usize {
+            self.data[i * 4..i * 4 + 4].copy_from_slice(&c);
+        }
+    }
+
+    /// Draw a 1-pixel-wide axis-aligned horizontal line.
+    fn hline(&mut self, y: i32, x0: i32, x1: i32, c: [u8; 4]) {
+        for x in x0..=x1 {
+            self.set(x, y, c);
+        }
+    }
+
+    /// Draw a 1-pixel-wide axis-aligned vertical line.
+    fn vline(&mut self, x: i32, y0: i32, y1: i32, c: [u8; 4]) {
+        for y in y0..=y1 {
+            self.set(x, y, c);
+        }
+    }
+
+    /// Draw a filled diamond outline (ring) of given half-extents and line thickness.
+    fn diamond_ring(&mut self, cx: f32, cy: f32, rx: f32, ry: f32, thickness: f32, c: [u8; 4]) {
+        for y in (cy - ry - 2.0) as i32..=(cy + ry + 2.0) as i32 {
+            for x in (cx - rx - 2.0) as i32..=(cx + rx + 2.0) as i32 {
+                let nx = (x as f32 - cx).abs() / rx;
+                let ny = (y as f32 - cy).abs() / ry;
+                let dist = nx + ny;
+                if dist <= 1.0 && dist >= 1.0 - (thickness / rx.min(ry)) {
+                    self.set(x, y, c);
+                }
+            }
+        }
+    }
+
+    fn set(&mut self, x: i32, y: i32, c: [u8; 4]) {
+        if x < 0 || y < 0 || x >= W as i32 || y >= H as i32 { return; }
+        let i = (y as u32 * W + x as u32) as usize * 4;
+        let a = c[3] as f32 / 255.0;
+        if a >= 0.99 {
+            self.data[i..i + 4].copy_from_slice(&c);
+        } else if a > 0.01 {
+            self.data[i]     = (self.data[i]     as f32 * (1.0 - a) + c[0] as f32 * a) as u8;
+            self.data[i + 1] = (self.data[i + 1] as f32 * (1.0 - a) + c[1] as f32 * a) as u8;
+            self.data[i + 2] = (self.data[i + 2] as f32 * (1.0 - a) + c[2] as f32 * a) as u8;
+            self.data[i + 3] = 255;
+        }
+    }
+
+    fn circle(&mut self, cx: f32, cy: f32, r: f32, c: [u8; 4]) {
+        for y in (cy - r - 1.0) as i32..=(cy + r + 1.0) as i32 {
+            for x in (cx - r - 1.0) as i32..=(cx + r + 1.0) as i32 {
+                if (x as f32 - cx).powi(2) + (y as f32 - cy).powi(2) <= r * r {
+                    self.set(x, y, c);
+                }
+            }
+        }
+    }
+
+    fn fill_rect(&mut self, x: i32, y: i32, w: i32, h: i32, c: [u8; 4]) {
+        for ry in y..y + h {
+            for rx in x..x + w {
+                self.set(rx, ry, c);
+            }
+        }
+    }
+
+    fn triangle(&mut self, pts: [(f32, f32); 3], c: [u8; 4]) {
+        let min_x = pts.iter().map(|p| p.0).fold(f32::INFINITY, f32::min) as i32;
+        let max_x = pts.iter().map(|p| p.0).fold(f32::NEG_INFINITY, f32::max) as i32;
+        let min_y = pts.iter().map(|p| p.1).fold(f32::INFINITY, f32::min) as i32;
+        let max_y = pts.iter().map(|p| p.1).fold(f32::NEG_INFINITY, f32::max) as i32;
+        let (ax, ay) = pts[0];
+        let (bx, by) = pts[1];
+        let (ex, ey) = pts[2];
+        for y in min_y..=max_y {
+            for x in min_x..=max_x {
+                let px = x as f32 + 0.5;
+                let py = y as f32 + 0.5;
+                let d0 = (bx - ax) * (py - ay) - (by - ay) * (px - ax);
+                let d1 = (ex - bx) * (py - by) - (ey - by) * (px - bx);
+                let d2 = (ax - ex) * (py - ey) - (ay - ey) * (px - ex);
+                let neg = d0 < 0.0 || d1 < 0.0 || d2 < 0.0;
+                let pos = d0 > 0.0 || d1 > 0.0 || d2 > 0.0;
+                if !(neg && pos) {
+                    self.set(x, y, c);
+                }
+            }
+        }
+    }
+
+    fn diamond(&mut self, cx: f32, cy: f32, rx: f32, ry: f32, c: [u8; 4]) {
+        for y in (cy - ry - 1.0) as i32..=(cy + ry + 1.0) as i32 {
+            for x in (cx - rx - 1.0) as i32..=(cx + rx + 1.0) as i32 {
+                let nx = (x as f32 - cx).abs() / rx;
+                let ny = (y as f32 - cy).abs() / ry;
+                if nx + ny <= 1.0 {
+                    self.set(x, y, c);
+                }
+            }
+        }
+    }
+}
+
+// ---------------------------------------------------------------------------
+// Suit symbol drawing
+// ---------------------------------------------------------------------------
+
+fn draw_suit(cv: &mut Canvas, cx: f32, cy: f32, sz: f32, suit: u8, c: [u8; 4]) {
+    match suit {
+        0 => draw_club(cv, cx, cy, sz, c),
+        1 => draw_diamond_sym(cv, cx, cy, sz, c),
+        2 => draw_heart(cv, cx, cy, sz, c),
+        _ => draw_spade(cv, cx, cy, sz, c),
+    }
+}
+
+fn draw_heart(cv: &mut Canvas, cx: f32, cy: f32, sz: f32, c: [u8; 4]) {
+    let r = sz * 0.33;
+    let oy = cy - sz * 0.04;
+    cv.circle(cx - sz * 0.22, oy, r, c);
+    cv.circle(cx + sz * 0.22, oy, r, c);
+    cv.triangle([
+        (cx - sz * 0.52, oy + r * 0.4),
+        (cx + sz * 0.52, oy + r * 0.4),
+        (cx, cy + sz * 0.52),
+    ], c);
+}
+
+fn draw_spade(cv: &mut Canvas, cx: f32, cy: f32, sz: f32, c: [u8; 4]) {
+    cv.triangle([
+        (cx, cy - sz * 0.52),
+        (cx - sz * 0.52, cy + sz * 0.1),
+        (cx + sz * 0.52, cy + sz * 0.1),
+    ], c);
+    cv.circle(cx - sz * 0.22, cy + sz * 0.06, sz * 0.3, c);
+    cv.circle(cx + sz * 0.22, cy + sz * 0.06, sz * 0.3, c);
+    // stem + base
+    cv.triangle([
+        (cx, cy + sz * 0.12),
+        (cx - sz * 0.13, cy + sz * 0.5),
+        (cx + sz * 0.13, cy + sz * 0.5),
+    ], c);
+    cv.fill_rect(
+        (cx - sz * 0.26) as i32,
+        (cy + sz * 0.43) as i32,
+        (sz * 0.52) as i32,
+        (sz * 0.1) as i32,
+        c,
+    );
+}
+
+fn draw_diamond_sym(cv: &mut Canvas, cx: f32, cy: f32, sz: f32, c: [u8; 4]) {
+    cv.diamond(cx, cy, sz * 0.44, sz * 0.57, c);
+}
+
+fn draw_club(cv: &mut Canvas, cx: f32, cy: f32, sz: f32, c: [u8; 4]) {
+    let r = sz * 0.29;
+    cv.circle(cx, cy - sz * 0.22, r, c);
+    cv.circle(cx - sz * 0.28, cy + sz * 0.1, r, c);
+    cv.circle(cx + sz * 0.28, cy + sz * 0.1, r, c);
+    cv.fill_rect(
+        (cx - sz * 0.08) as i32,
+        (cy + sz * 0.22) as i32,
+        (sz * 0.16) as i32 + 1,
+        (sz * 0.27) as i32,
+        c,
+    );
+    cv.fill_rect(
+        (cx - sz * 0.26) as i32,
+        (cy + sz * 0.45) as i32,
+        (sz * 0.52) as i32,
+        (sz * 0.09) as i32,
+        c,
+    );
+}
+
+// ---------------------------------------------------------------------------
+// Text rendering via ab_glyph
+// ---------------------------------------------------------------------------
+
+fn draw_text(cv: &mut Canvas, font: &FontRef<'_>, text: &str, px: f32, left: f32, top: f32, c: [u8; 4]) {
+    let scale = PxScale::from(px);
+    let baseline = top + font.as_scaled(scale).ascent();
+    let mut x = left;
+    for ch in text.chars() {
+        let gid = font.glyph_id(ch);
+        let glyph = gid.with_scale_and_position(scale, ab_glyph::point(x, baseline));
+        let adv = font.as_scaled(scale).h_advance(gid);
+        if let Some(outlined) = font.outline_glyph(glyph) {
+            let bounds = outlined.px_bounds();
+            outlined.draw(|gx, gy, cov| {
+                if cov > 0.02 {
+                    let alpha = (cov * c[3] as f32) as u8;
+                    cv.set(
+                        (bounds.min.x + gx as f32) as i32,
+                        (bounds.min.y + gy as f32) as i32,
+                        [c[0], c[1], c[2], alpha],
+                    );
+                }
+            });
+        }
+        x += adv;
+    }
+}
+
+fn text_w(font: &FontRef<'_>, text: &str, px: f32) -> f32 {
+    let scale = PxScale::from(px);
+    let sf = font.as_scaled(scale);
+    text.chars().map(|c| sf.h_advance(font.glyph_id(c))).sum()
+}
+
+fn text_h(font: &FontRef<'_>, px: f32) -> f32 {
+    let scale = PxScale::from(px);
+    let sf = font.as_scaled(scale);
+    sf.ascent() - sf.descent()
+}
+
+// ---------------------------------------------------------------------------
+// Pip layout (rank 0=Ace … 9=Ten; rank 10-12 are face cards)
+// ---------------------------------------------------------------------------
+
+fn pip_positions(rank: u8) -> &'static [(f32, f32)] {
+    match rank {
+        0 => &[(0.5, 0.5)],
+        1 => &[(0.5, 0.2), (0.5, 0.8)],
+        2 => &[(0.5, 0.12), (0.5, 0.5), (0.5, 0.88)],
+        3 => &[(0.25, 0.18), (0.75, 0.18), (0.25, 0.82), (0.75, 0.82)],
+        4 => &[(0.25, 0.18), (0.75, 0.18), (0.5, 0.5), (0.25, 0.82), (0.75, 0.82)],
+        5 => &[(0.25, 0.12), (0.75, 0.12), (0.25, 0.5), (0.75, 0.5), (0.25, 0.88), (0.75, 0.88)],
+        6 => &[(0.25, 0.1), (0.75, 0.1), (0.5, 0.31), (0.25, 0.5), (0.75, 0.5), (0.25, 0.9), (0.75, 0.9)],
+        7 => &[(0.25, 0.1), (0.75, 0.1), (0.5, 0.28), (0.25, 0.48), (0.75, 0.48), (0.5, 0.70), (0.25, 0.9), (0.75, 0.9)],
+        8 => &[(0.25, 0.1), (0.75, 0.1), (0.25, 0.35), (0.75, 0.35), (0.5, 0.5), (0.25, 0.65), (0.75, 0.65), (0.25, 0.9), (0.75, 0.9)],
+        9 => &[(0.25, 0.09), (0.75, 0.09), (0.5, 0.27), (0.25, 0.44), (0.75, 0.44), (0.25, 0.56), (0.75, 0.56), (0.5, 0.73), (0.25, 0.91), (0.75, 0.91)],
+        _ => &[],
+    }
+}
+
+// Pip area within the card (avoids the corner labels).
+const PIP_X: f32 = 22.0;
+const PIP_Y: f32 = 46.0;
+const PIP_W: f32 = 76.0;
+const PIP_H: f32 = 80.0;
+
+// ---------------------------------------------------------------------------
+// Card face generation
+// ---------------------------------------------------------------------------
+
+fn make_card_face(font: &FontRef<'_>, rank: u8, suit: u8) -> Canvas {
+    let mut cv = Canvas::new();
+    let sc = suit_color(suit);
+
+    // Border (2 px)
+    for x in 0..W as i32 {
+        cv.set(x, 0, BORDER);
+        cv.set(x, 1, BORDER);
+        cv.set(x, H as i32 - 2, BORDER);
+        cv.set(x, H as i32 - 1, BORDER);
+    }
+    for y in 0..H as i32 {
+        cv.set(0, y, BORDER);
+        cv.set(1, y, BORDER);
+        cv.set(W as i32 - 2, y, BORDER);
+        cv.set(W as i32 - 1, y, BORDER);
+    }
+
+    let rank_s = rank_str(rank);
+    let rank_px = 18.0f32;
+    let suit_sz = 11.0f32;
+    let rh = text_h(font, rank_px);
+    let rw = text_w(font, rank_s, rank_px);
+    let corner_h = rh + 2.0 + suit_sz * 1.5;
+
+    // Top-left corner
+    let tl_x = 6.0f32;
+    let tl_y = 5.0f32;
+    draw_text(&mut cv, font, rank_s, rank_px, tl_x, tl_y, sc);
+    draw_suit(&mut cv, tl_x + suit_sz * 0.62, tl_y + rh + 2.0 + suit_sz * 0.75, suit_sz, suit, sc);
+
+    // Bottom-right corner (right-aligned rank, suit above it)
+    let br_rx = W as f32 - 6.0;
+    let br_by = H as f32 - 5.0;
+    let br_ty = br_by - corner_h;
+    draw_text(&mut cv, font, rank_s, rank_px, br_rx - rw, br_ty, sc);
+    draw_suit(&mut cv, br_rx - suit_sz * 0.62, br_ty + rh + 2.0 + suit_sz * 0.75, suit_sz, suit, sc);
+
+    // Center content
+    if rank >= 10 {
+        // Face cards: large rank letter + suit symbol below
+        let big_px = 52.0f32;
+        let big_w = text_w(font, rank_s, big_px);
+        let big_h = text_h(font, big_px);
+        let big_x = (W as f32 - big_w) / 2.0;
+        let big_y = H as f32 * 0.28;
+        draw_text(&mut cv, font, rank_s, big_px, big_x, big_y, sc);
+        let sym_sz = 22.0f32;
+        draw_suit(&mut cv, W as f32 * 0.5, big_y + big_h + sym_sz * 1.0, sym_sz, suit, sc);
+    } else {
+        // Pip cards
+        let pip_sz = if rank == 0 {
+            24.0f32 // Ace: large single pip
+        } else if rank <= 5 {
+            14.0
+        } else {
+            12.0
+        };
+        for &(nx, ny) in pip_positions(rank) {
+            let cx = PIP_X + nx * PIP_W;
+            let cy = PIP_Y + ny * PIP_H;
+            draw_suit(&mut cv, cx, cy, pip_sz, suit, sc);
+        }
+    }
+
+    cv
+}
+
+// ---------------------------------------------------------------------------
+// PNG encoding helpers
+// ---------------------------------------------------------------------------
+
+fn save_card_png(path: &Path, cv: &Canvas) {
+    save_png_wh(path, &cv.data, W, H);
+}
+
+fn save_png_wh(path: &Path, data: &[u8], w: u32, h: u32) {
+    let file = File::create(path)
+        .unwrap_or_else(|e| panic!("cannot create {}: {e}", path.display()));
+    let mut bw = BufWriter::new(file);
+    let mut enc = png::Encoder::new(&mut bw, w, h);
+    enc.set_color(png::ColorType::Rgba);
+    enc.set_depth(png::BitDepth::Eight);
+    let mut writer = enc.write_header()
+        .unwrap_or_else(|e| panic!("png header error for {}: {e}", path.display()));
+    writer.write_image_data(data)
+        .unwrap_or_else(|e| panic!("png data error for {}: {e}", path.display()));
+}
+
+// ---------------------------------------------------------------------------
+// Card backs (120×168 with distinctive patterns)
+// ---------------------------------------------------------------------------
+
+/// back_0 – blue: repeating diamond grid pattern
+fn make_back_0() -> Canvas {
+    const BASE: [u8; 4] = [0x26, 0x4D, 0x8C, 0xFF];
+    const LIGHT: [u8; 4] = [0x5A, 0x80, 0xBF, 0xFF];
+    const HIGHLIGHT: [u8; 4] = [0xA0, 0xC0, 0xFF, 0xB0];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+
+    // 2-pixel border
+    let bw = 4i32;
+    for x in 0..W as i32 { for t in 0..bw { cv.set(x, t, LIGHT); cv.set(x, H as i32 - 1 - t, LIGHT); } }
+    for y in 0..H as i32 { for t in 0..bw { cv.set(t, y, LIGHT); cv.set(W as i32 - 1 - t, y, LIGHT); } }
+
+    // Diamond grid: row/col spacing
+    let gx = 18.0f32;
+    let gy = 18.0f32;
+    let rx = gx * 0.45;
+    let ry = gy * 0.45;
+    let mut row = 0;
+    let mut cy = 6.0f32 + gy * 0.5;
+    while cy < H as f32 - 4.0 {
+        let offset = if row % 2 == 0 { 0.0 } else { gx * 0.5 };
+        let mut cx = 6.0f32 + gx * 0.5 + offset;
+        while cx < W as f32 - 4.0 {
+            cv.diamond_ring(cx, cy, rx, ry, 1.5, LIGHT);
+            // tiny highlight dot at centre of each diamond
+            cv.circle(cx, cy, 1.5, HIGHLIGHT);
+            cx += gx;
+        }
+        cy += gy;
+        row += 1;
+    }
+    cv
+}
+
+/// back_1 – red: diagonal crosshatch
+fn make_back_1() -> Canvas {
+    const BASE: [u8; 4] = [0x8C, 0x1A, 0x1A, 0xFF];
+    const LINE: [u8; 4] = [0xCC, 0x55, 0x55, 0xC0];
+    const BORDER: [u8; 4] = [0xDD, 0x88, 0x88, 0xFF];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+
+    // Diagonal lines every 12 px (NW→SE)
+    let spacing = 12i32;
+    for k in (-(H as i32)..W as i32).step_by(spacing as usize) {
+        for t in 0..W as i32 {
+            let y = t + k;
+            cv.set(t, y, LINE);
+            // 1 px thick — also set neighbour for slightly bolder line
+            cv.set(t, y + 1, LINE);
+        }
+    }
+    // Diagonal lines (NE→SW)
+    for k in (0..(W as i32 + H as i32)).step_by(spacing as usize) {
+        for t in 0..W as i32 {
+            let y = k - t;
+            cv.set(t, y, LINE);
+            cv.set(t, y + 1, LINE);
+        }
+    }
+
+    // 4-pixel border
+    let bw = 4i32;
+    for x in 0..W as i32 { for t in 0..bw { cv.set(x, t, BORDER); cv.set(x, H as i32 - 1 - t, BORDER); } }
+    for y in 0..H as i32 { for t in 0..bw { cv.set(t, y, BORDER); cv.set(W as i32 - 1 - t, y, BORDER); } }
+    cv
+}
+
+/// back_2 – green: evenly spaced small circle array
+fn make_back_2() -> Canvas {
+    const BASE: [u8; 4] = [0x0D, 0x66, 0x1A, 0xFF];
+    const DOT: [u8; 4] = [0x40, 0xCC, 0x55, 0xE0];
+    const BORDER: [u8; 4] = [0x55, 0xDD, 0x66, 0xFF];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+
+    // 4-pixel border
+    let bw = 4i32;
+    for x in 0..W as i32 { for t in 0..bw { cv.set(x, t, BORDER); cv.set(x, H as i32 - 1 - t, BORDER); } }
+    for y in 0..H as i32 { for t in 0..bw { cv.set(t, y, BORDER); cv.set(W as i32 - 1 - t, y, BORDER); } }
+
+    // Circle array (staggered rows)
+    let gx = 16.0f32;
+    let gy = 16.0f32;
+    let r = 3.5f32;
+    let mut row = 0;
+    let mut cy = 8.0f32 + gy * 0.5;
+    while cy < H as f32 - 6.0 {
+        let offset = if row % 2 == 0 { 0.0 } else { gx * 0.5 };
+        let mut cx = 8.0f32 + gx * 0.5 + offset;
+        while cx < W as f32 - 6.0 {
+            cv.circle(cx, cy, r, DOT);
+            cx += gx;
+        }
+        cy += gy;
+        row += 1;
+    }
+    cv
+}
+
+/// back_3 – purple: concentric diamond outlines
+fn make_back_3() -> Canvas {
+    const BASE: [u8; 4] = [0x59, 0x14, 0x85, 0xFF];
+    const RING: [u8; 4] = [0xA0, 0x60, 0xDD, 0xD0];
+    const BORDER: [u8; 4] = [0xBB, 0x77, 0xFF, 0xFF];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+
+    // Concentric diamonds from centre
+    let cx = W as f32 * 0.5;
+    let cy = H as f32 * 0.5;
+    let mut rx = 8.0f32;
+    let step = 12.0f32;
+    while rx < (W as f32).max(H as f32) {
+        let ry = rx * (H as f32 / W as f32);
+        cv.diamond_ring(cx, cy, rx, ry, 1.5, RING);
+        rx += step;
+    }
+
+    // 4-pixel border
+    let bw = 4i32;
+    for x in 0..W as i32 { for t in 0..bw { cv.set(x, t, BORDER); cv.set(x, H as i32 - 1 - t, BORDER); } }
+    for y in 0..H as i32 { for t in 0..bw { cv.set(t, y, BORDER); cv.set(W as i32 - 1 - t, y, BORDER); } }
+    cv
+}
+
+/// back_4 – teal: horizontal stripes with thin decorative lines
+fn make_back_4() -> Canvas {
+    const BASE: [u8; 4] = [0x0D, 0x66, 0x6B, 0xFF];
+    const STRIPE: [u8; 4] = [0x1A, 0x99, 0xA0, 0x90];
+    const DECO: [u8; 4] = [0x55, 0xCC, 0xD4, 0xA0];
+    const BORDER: [u8; 4] = [0x44, 0xBB, 0xC4, 0xFF];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+
+    // Horizontal stripes every 10 px (2 px wide)
+    let mut y = 6i32;
+    while y < H as i32 - 4 {
+        cv.hline(y, 5, W as i32 - 6, STRIPE);
+        cv.hline(y + 1, 5, W as i32 - 6, STRIPE);
+        y += 10;
+    }
+    // Thin decorative horizontal lines between stripes
+    let mut y = 10i32;
+    while y < H as i32 - 4 {
+        cv.hline(y, 14, W as i32 - 15, DECO);
+        y += 10;
+    }
+
+    // 4-pixel border
+    let bw = 4i32;
+    for x in 0..W as i32 { for t in 0..bw { cv.set(x, t, BORDER); cv.set(x, H as i32 - 1 - t, BORDER); } }
+    for y in 0..H as i32 { for t in 0..bw { cv.set(t, y, BORDER); cv.set(W as i32 - 1 - t, y, BORDER); } }
+    cv
+}
+
+// ---------------------------------------------------------------------------
+// Backgrounds (120×168 textured patterns)
+// ---------------------------------------------------------------------------
+
+/// bg_0 – dark green felt: subtle grid of faint lines giving a woven texture
+fn make_bg_0() -> Canvas {
+    const BASE: [u8; 4] = [0x1A, 0x4D, 0x1A, 0xFF];
+    const WARP: [u8; 4] = [0x22, 0x60, 0x22, 0x90]; // slightly lighter horizontal threads
+    const WEFT: [u8; 4] = [0x15, 0x40, 0x15, 0x90]; // slightly darker vertical threads
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+    // Horizontal warp lines every 4 px
+    for y in (0..H as i32).step_by(4) {
+        cv.hline(y, 0, W as i32 - 1, WARP);
+    }
+    // Vertical weft lines every 4 px
+    for x in (0..W as i32).step_by(4) {
+        cv.vline(x, 0, H as i32 - 1, WEFT);
+    }
+    cv
+}
+
+/// bg_1 – wood brown: horizontal planks with grain lines
+fn make_bg_1() -> Canvas {
+    const BASE: [u8; 4] = [0x40, 0x2D, 0x1A, 0xFF];
+    const PLANK_EDGE: [u8; 4] = [0x28, 0x1A, 0x0A, 0xFF]; // dark plank separator
+    const GRAIN: [u8; 4] = [0x55, 0x3D, 0x28, 0xA0];      // lighter grain streak
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+    // Horizontal plank edges every 24 px
+    for y in (0..H as i32).step_by(24) {
+        cv.hline(y, 0, W as i32 - 1, PLANK_EDGE);
+        cv.hline(y + 1, 0, W as i32 - 1, PLANK_EDGE);
+    }
+    // Grain lines within each plank (every 3 px between plank edges)
+    for y in (0..H as i32).step_by(3) {
+        // Skip the plank edge rows
+        if y % 24 < 2 { continue; }
+        cv.hline(y, 2, W as i32 - 3, GRAIN);
+    }
+    cv
+}
+
+/// bg_2 – navy: star-field dots scattered in a regular grid
+fn make_bg_2() -> Canvas {
+    const BASE: [u8; 4] = [0x0D, 0x14, 0x38, 0xFF];
+    const STAR_A: [u8; 4] = [0xCC, 0xDD, 0xFF, 0xD0];
+    const STAR_B: [u8; 4] = [0x80, 0xA0, 0xDD, 0x80];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+    // Bright small stars on a staggered grid
+    let gx = 14.0f32;
+    let gy = 16.0f32;
+    let mut row = 0u32;
+    let mut cy = gy * 0.5;
+    while cy < H as f32 {
+        let offset = if row.is_multiple_of(2) { 0.0 } else { gx * 0.5 };
+        let mut cx = gx * 0.5 + offset;
+        while cx < W as f32 {
+            // alternate bright/dim to give depth
+            let c = if (row + (cx / gx) as u32).is_multiple_of(3) { STAR_A } else { STAR_B };
+            cv.circle(cx, cy, 1.0, c);
+            cx += gx;
+        }
+        cy += gy;
+        row += 1;
+    }
+    cv
+}
+
+/// bg_3 – burgundy: diagonal tile pattern
+fn make_bg_3() -> Canvas {
+    const BASE: [u8; 4] = [0x4D, 0x0D, 0x14, 0xFF];
+    const LINE: [u8; 4] = [0x77, 0x22, 0x30, 0xB0];
+    const ACCENT: [u8; 4] = [0x99, 0x33, 0x44, 0x80];
+    let mut cv = Canvas::new();
+    cv.fill_solid(BASE);
+    // Diagonal lines in one direction every 16 px
+    let spacing = 16i32;
+    for k in (-(H as i32)..W as i32 + H as i32).step_by(spacing as usize) {
+        for t in 0..W as i32 {
+            let y = t + k;
+            cv.set(t, y, LINE);
+        }
+    }
+    // Diagonal lines in the other direction every 16 px (accent colour)
+    for k in (0..W as i32 + H as i32).step_by(spacing as usize) {
+        for t in 0..W as i32 {
+            let y = k - t;
+            cv.set(t, y, ACCENT);
+        }
+    }
+    cv
+}
+
+/// bg_4 – charcoal: subtle checkerboard texture
+fn make_bg_4() -> Canvas {
+    const DARK: [u8; 4] = [0x1F, 0x1F, 0x24, 0xFF];
+    const LIGHT: [u8; 4] = [0x2C, 0x2C, 0x33, 0xFF];
+    let mut cv = Canvas::new();
+    cv.fill_solid(DARK);
+    // 4×4 checkerboard
+    for y in 0..H as i32 {
+        for x in 0..W as i32 {
+            if ((x / 4) + (y / 4)) % 2 == 0 {
+                cv.set(x, y, LIGHT);
+            }
+        }
+    }
+    cv
+}
+
+// ---------------------------------------------------------------------------
+// Entry point
+// ---------------------------------------------------------------------------
+
+fn workspace_root() -> std::path::PathBuf {
+    let crate_dir = std::path::PathBuf::from(env!("CARGO_MANIFEST_DIR"));
+    crate_dir.parent().unwrap().to_path_buf()
+}
+
+fn main() {
+    let root = workspace_root();
+    std::fs::create_dir_all(root.join("assets/cards/faces")).unwrap();
+    std::fs::create_dir_all(root.join("assets/cards/backs")).unwrap();
+    std::fs::create_dir_all(root.join("assets/backgrounds")).unwrap();
+
+    // Load font from disk (dev tool — runtime load is fine here).
+    let font_path = root.join("assets/fonts/main.ttf");
+    let font_bytes = std::fs::read(&font_path)
+        .unwrap_or_else(|e| panic!("failed to read {}: {e}", font_path.display()));
+    let font = FontRef::try_from_slice(&font_bytes)
+        .expect("failed to parse assets/fonts/main.ttf");
+
+    // 52 card faces
+    let suits = ["c", "d", "h", "s"];
+    let ranks = ["a","2","3","4","5","6","7","8","9","10","j","q","k"];
+    for suit in 0u8..4 {
+        for rank in 0u8..13 {
+            let cv = make_card_face(&font, rank, suit);
+            let name = format!("{}_{}.png", ranks[rank as usize], suits[suit as usize]);
+            let path = root.join("assets/cards/faces").join(&name);
+            save_card_png(&path, &cv);
+            println!("wrote {}", path.display());
+        }
+    }
+
+    // Card backs
+    for (i, cv) in [make_back_0(), make_back_1(), make_back_2(), make_back_3(), make_back_4()].iter().enumerate() {
+        let path = root.join(format!("assets/cards/backs/back_{i}.png"));
+        save_card_png(&path, cv);
+        println!("wrote {}", path.display());
+    }
+
+    // Backgrounds
+    for (i, cv) in [make_bg_0(), make_bg_1(), make_bg_2(), make_bg_3(), make_bg_4()].iter().enumerate() {
+        let path = root.join(format!("assets/backgrounds/bg_{i}.png"));
+        save_card_png(&path, cv);
+        println!("wrote {}", path.display());
+    }
+
+    println!("gen_art: all assets generated successfully.");
+}

solitaire_assetgen/src/bin/gen_sfx.rs

@@ -16,16 +16,17 @@ fn main() -> io::Result<()> {
     let out_dir = workspace_root().join("assets").join("audio");
     fs::create_dir_all(&out_dir)?;
 
-    let effects: [(&str, Generator); 5] = [
+    let effects: [(&str, Generator); 6] = [
         ("card_flip.wav", card_flip),
         ("card_place.wav", card_place),
         ("card_deal.wav", card_deal),
         ("card_invalid.wav", card_invalid),
         ("win_fanfare.wav", win_fanfare),
+        ("ambient_loop.wav", ambient_loop),
     ];
 
-    for (name, gen) in &effects {
+    for (name, make) in &effects {
-        let samples = gen();
+        let samples = make();
         let path = out_dir.join(name);
         write_wav_mono_pcm16(&path, SAMPLE_RATE, &samples)?;
         println!("wrote {} ({} samples)", path.display(), samples.len());
@@ -169,6 +170,64 @@ fn win_fanfare() -> Vec<i16> {
     out
 }
 
+/// Generates a seamlessly looping ambient drone track (~6 seconds, 44100 Hz
+/// mono 16-bit PCM).
+///
+/// Design:
+/// - Fundamental: 55 Hz (low A) sine wave.
+/// - Harmonics: 110 Hz at 40% and 165 Hz at 20% for warmth.
+/// - Amplitude LFO at 0.1 Hz creates a slow breath / pad swell.
+/// - The loop length is chosen so both the fundamental and LFO complete an
+///   integer number of cycles — guaranteeing a phase-continuous seamless loop.
+/// - Peak amplitude is kept low (0.18) so it sits quietly under SFX.
+fn ambient_loop() -> Vec<i16> {
+    use std::f32::consts::PI;
+
+    // LFO period = 10 s; fundamental period ≈ 18.18 ms.
+    // We want a loop that is an exact integer multiple of both, so both
+    // complete a whole number of cycles with no phase discontinuity.
+    //
+    // LCM approach: fundamental @ 55 Hz repeats every 1/55 s. The LFO @ 0.1 Hz
+    // repeats every 10 s. 10 s is already a multiple of 1/55 s (10 * 55 = 550
+    // cycles), so a 10-second buffer loops perfectly. We halve it to 5 s for
+    // a smaller file — 5 * 55 = 275 (integer), 5 * 0.1 = 0.5 (half-cycle of
+    // LFO). To keep a full LFO cycle we use 10 s but write only the first 5 s
+    // of the waveform, which is within the 4–8 s budget and still a seamless
+    // loop because the LFO amplitude is symmetric about its midpoint at t=5 s.
+    //
+    // Simpler explanation: at exactly 5 s, both the 55 Hz tone and a slow
+    // 0.2 Hz (period=5 s) breath LFO complete an integer number of cycles.
+    // We use 0.2 Hz for the LFO instead of 0.1 Hz so the full envelope fits
+    // in one loop period.
+    let lfo_freq = 0.2_f32; // 1 full LFO cycle per 5-second loop
+    let loop_seconds = 1.0 / lfo_freq; // = 5.0 s
+    let n = (loop_seconds * SAMPLE_RATE as f32) as usize;
+
+    let f0 = 55.0_f32; // fundamental (Hz)
+    let f1 = 110.0_f32; // 2nd harmonic
+    let f2 = 165.0_f32; // 3rd harmonic
+
+    let mut out = Vec::with_capacity(n);
+    for i in 0..n {
+        let t = i as f32 / SAMPLE_RATE as f32;
+
+        // LFO: smoothly oscillates between 0.4 and 1.0 amplitude.
+        // Using (1 - cos) / 2 instead of sin so the loop starts and ends at
+        // the same LFO phase (0.0 → both sin and cos are fully periodic).
+        let lfo = 0.7 + 0.3 * (2.0 * PI * lfo_freq * t).cos();
+
+        // Layered harmonics
+        let tone = (2.0 * PI * f0 * t).sin()
+            + 0.4 * (2.0 * PI * f1 * t).sin()
+            + 0.2 * (2.0 * PI * f2 * t).sin();
+
+        // Normalise the layered sum: max raw peak ≈ 1.6; keep final peak ≤ 0.18
+        let sample = tone / 1.6 * lfo * 0.18;
+        out.push(quantize(sample));
+    }
+    out
+}
+
 // ---------------------------------------------------------------------------
 // Minimal WAV writer (mono 16-bit PCM)
 // ---------------------------------------------------------------------------

solitaire_core/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name    = "solitaire_core"
 version.workspace = true
+license.workspace = true
 edition.workspace = true
 
 [dependencies]

solitaire_core/src/achievement.rs

@@ -12,20 +12,25 @@
 /// `StatsSnapshot`, the final `GameState`, and wall-clock time.
 #[derive(Debug, Clone)]
 pub struct AchievementContext {
-    // Stats (after this win has been recorded).
+    /// Total number of games played (after this win has been recorded).
     pub games_played: u32,
+    /// Total number of games won (after this win has been recorded).
     pub games_won: u32,
+    /// Current consecutive win streak (after this win has been recorded).
     pub win_streak_current: u32,
+    /// Highest single-game score ever achieved.
     pub best_single_score: u32,
+    /// Cumulative score across all games ever played.
     pub lifetime_score: u64,
+    /// Total wins completed in Draw 3 mode.
     pub draw_three_wins: u32,
 
-    // Progression.
     /// Current daily-challenge completion streak (consecutive days).
     pub daily_challenge_streak: u32,
 
-    // Last-win facts (GameWonEvent + GameState at win time).
+    /// Score achieved in the just-won game.
     pub last_win_score: i32,
+    /// Elapsed seconds for the just-won game.
     pub last_win_time_seconds: u64,
     /// `true` if `undo()` was called at least once during the won game.
     pub last_win_used_undo: bool,
@@ -55,13 +60,17 @@ pub enum Reward {
 /// A single achievement's static metadata + unlock condition.
 #[derive(Debug, Clone, Copy)]
 pub struct AchievementDef {
+    /// Unique string identifier for this achievement (e.g. `"first_win"`).
     pub id: &'static str,
+    /// Human-readable display name shown in the achievements screen.
     pub name: &'static str,
+    /// Flavour text describing how to unlock the achievement.
     pub description: &'static str,
     /// Hidden from the achievements screen until unlocked.
     pub secret: bool,
     /// Reward granted on first unlock. `None` for cosmetic-only recognition.
     pub reward: Option<Reward>,
+    /// Predicate evaluated on every `GameWonEvent` and `StateChangedEvent`. Returns true when the achievement should unlock.
     pub condition: fn(&AchievementContext) -> bool,
 }
 
@@ -477,6 +486,109 @@ mod tests {
         assert!(achievement_by_id("nonexistent").is_none());
     }
 
+    // -----------------------------------------------------------------------
+    // Direct predicate tests via ctx_defaults()
+    // -----------------------------------------------------------------------
+
+    /// Baseline context representing a single clean one-minute win in Draw-One mode.
+    fn ctx_defaults() -> AchievementContext {
+        AchievementContext {
+            games_played: 1,
+            games_won: 1,
+            win_streak_current: 1,
+            best_single_score: 0,
+            lifetime_score: 0,
+            draw_three_wins: 0,
+            daily_challenge_streak: 0,
+            last_win_score: 0,
+            last_win_time_seconds: 600,
+            last_win_used_undo: false,
+            wall_clock_hour: Some(12),
+            last_win_recycle_count: 0,
+            last_win_is_zen: false,
+        }
+    }
+
+    #[test]
+    fn speed_demon_true_when_under_three_minutes() {
+        let mut c = ctx_defaults();
+        c.last_win_time_seconds = 179;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(ids.contains(&"speed_demon"), "speed_demon should unlock at 179s");
+    }
+
+    #[test]
+    fn speed_demon_false_when_over_three_minutes() {
+        let mut c = ctx_defaults();
+        c.last_win_time_seconds = 181;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(!ids.contains(&"speed_demon"), "speed_demon must not unlock at 181s");
+    }
+
+    #[test]
+    fn lightning_true_when_under_90_seconds() {
+        let mut c = ctx_defaults();
+        c.last_win_time_seconds = 89;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(ids.contains(&"lightning"), "lightning should unlock at 89s");
+    }
+
+    #[test]
+    fn lightning_false_at_exactly_90_seconds() {
+        let mut c = ctx_defaults();
+        c.last_win_time_seconds = 90;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(!ids.contains(&"lightning"), "lightning must not unlock at exactly 90s");
+    }
+
+    #[test]
+    fn no_undo_true_when_zero_undos() {
+        let mut c = ctx_defaults();
+        c.last_win_used_undo = false;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(ids.contains(&"no_undo"), "no_undo should unlock when undo was not used");
+    }
+
+    #[test]
+    fn no_undo_false_when_undo_used() {
+        let mut c = ctx_defaults();
+        c.last_win_used_undo = true;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(!ids.contains(&"no_undo"), "no_undo must not unlock when undo was used");
+    }
+
+    #[test]
+    fn high_scorer_true_when_score_5000_or_more() {
+        let mut c = ctx_defaults();
+        c.best_single_score = 5_000;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(ids.contains(&"high_scorer"), "high_scorer should unlock at best_single_score=5000");
+    }
+
+    #[test]
+    fn high_scorer_false_when_below_5000() {
+        let mut c = ctx_defaults();
+        c.best_single_score = 4_999;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(!ids.contains(&"high_scorer"), "high_scorer must not unlock at best_single_score=4999");
+    }
+
+    #[test]
+    fn on_a_roll_true_at_streak_3() {
+        let mut c = ctx_defaults();
+        c.win_streak_current = 3;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(ids.contains(&"on_a_roll"), "on_a_roll should unlock at streak=3");
+    }
+
+    #[test]
+    fn comeback_true_when_three_or_more_recycles() {
+        let mut c = ctx_defaults();
+        c.last_win_recycle_count = 3;
+        let ids: Vec<&str> = check_achievements(&c).iter().map(|d| d.id).collect();
+        assert!(ids.contains(&"comeback"), "comeback should unlock at last_win_recycle_count=3");
+    }
+
     #[test]
     fn on_a_roll_requires_streak_of_3() {
         let mut c = ctx();

solitaire_core/src/card.rs

@@ -63,9 +63,13 @@ impl Rank {
 /// A single playing card.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Card {
+    /// Unique identifier for this card within the deal. Stable across moves and undo.
     pub id: u32,
+    /// The card's suit (Clubs, Diamonds, Hearts, Spades).
     pub suit: Suit,
+    /// The card's rank (Ace through King).
     pub rank: Rank,
+    /// Whether the card is visible to the player. Face-down cards may not be moved.
     pub face_up: bool,
 }
 

solitaire_core/src/deck.rs

@@ -12,6 +12,7 @@ const ALL_RANKS: [Rank; 13] = [
 
 /// A standard 52-card deck.
 pub struct Deck {
+    /// All 52 cards in the deck, in deal order.
     pub cards: Vec<Card>,
 }
 

solitaire_core/src/game_state.rs

@@ -30,7 +30,9 @@ mod pile_map_serde {
 /// Whether cards are drawn one at a time or three at a time from the stock.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub enum DrawMode {
+    /// Draw one card from stock per turn.
     DrawOne,
+    /// Draw three cards from stock per turn; only the top is playable.
     DrawThree,
 }
 
@@ -46,9 +48,13 @@ pub enum DrawMode {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
 pub enum GameMode {
     #[default]
+    /// Standard Klondike rules with score and timer.
     Classic,
+    /// No timer, no score display, ambient audio only.
     Zen,
+    /// Fixed hard seeds, no undo, must win to advance.
     Challenge,
+    /// Play as many games as possible within 10 minutes.
     TimeAttack,
 }
 
@@ -64,18 +70,26 @@ struct StateSnapshot {
 /// Full state of an in-progress Klondike Solitaire game.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct GameState {
+    /// All card piles keyed by pile type. Contains Stock, Waste, 4 Foundations, and 7 Tableau piles.
     #[serde(with = "pile_map_serde")]
     pub piles: HashMap<PileType, Pile>,
+    /// Whether the player draws one or three cards from the stock per turn.
     pub draw_mode: DrawMode,
     /// Top-level mode (Classic / Zen). Defaults to Classic for backwards
     /// compatibility with older save files via `#[serde(default)]`.
     #[serde(default)]
     pub mode: GameMode,
+    /// Current game score. Can be negative (undo penalties subtract from score).
     pub score: i32,
+    /// Total moves made this game, including draws and stock recycles.
     pub move_count: u32,
+    /// Seconds elapsed since the game started, used for time-bonus scoring.
     pub elapsed_seconds: u64,
+    /// RNG seed used to deal this game. Same seed always produces the same layout.
     pub seed: u64,
+    /// True once all 52 cards are on the foundations. No further moves are accepted.
     pub is_won: bool,
+    /// True when the game can be completed without further input (all remaining cards are face-up and in order).
     pub is_auto_completable: bool,
     /// Number of times `undo()` has been successfully invoked this game.
     /// Used by achievement conditions like `no_undo`.
@@ -173,6 +187,7 @@ impl GameState {
                 stock.cards.push(card);
             }
             self.recycle_count = self.recycle_count.saturating_add(1);
+            self.move_count += 1;
             return Ok(());
         }
 
@@ -274,10 +289,9 @@ impl GameState {
             .ok_or(MoveError::InvalidSource)?
             .cards
             .last_mut()
+            && !top.face_up
         {
-            if !top.face_up {
+            top.face_up = true;
-                top.face_up = true;
-            }
         }
 
         self.piles.get_mut(&to).ok_or(MoveError::InvalidDestination)?.cards.append(&mut moved);
@@ -352,6 +366,15 @@ impl GameState {
     /// Scans tableau piles 0–6 in order, returning the first top card that
     /// can be placed on any foundation pile. The scan order ensures Aces are
     /// resolved before higher ranks that depend on them.
+    ///
+    /// # Precondition
+    ///
+    /// This function is only called when `is_auto_completable` is `true`.
+    /// Auto-completability requires the waste pile to be empty, as enforced by
+    /// [`check_auto_complete`](Self::check_auto_complete) — it returns `false`
+    /// whenever `piles[Waste]` is non-empty. Therefore, skipping the waste pile
+    /// in this scan is intentional and correct: by the time this function is
+    /// reached, there are guaranteed to be no cards there to move.
     pub fn next_auto_complete_move(&self) -> Option<(PileType, PileType)> {
         if !self.is_auto_completable || self.is_won {
             return None;
@@ -562,6 +585,24 @@ mod tests {
         assert_eq!(g.recycle_count, 2);
     }
 
+    #[test]
+    fn move_count_increments_on_recycle() {
+        let mut g = new_game();
+        // Drain stock to waste, recording how many draws it took.
+        let mut draws: u32 = 0;
+        while !g.piles[&PileType::Stock].cards.is_empty() {
+            g.draw().unwrap();
+            draws += 1;
+        }
+        let before = g.move_count;
+        g.draw().unwrap(); // recycle
+        assert_eq!(
+            g.move_count,
+            before + 1,
+            "recycling waste back to stock must increment move_count (was {before}, draws={draws})"
+        );
+    }
+
     #[test]
     fn draw_from_empty_stock_and_waste_returns_error() {
         // The only stop condition for draw() is: both stock AND waste are
@@ -949,6 +990,24 @@ mod tests {
         assert_eq!(g.compute_time_bonus(), 7000);
     }
 
+    // --- EmptySource error path ---
+
+    #[test]
+    fn move_from_empty_pile_returns_empty_source() {
+        // Build a game state, clear a tableau pile entirely, then attempt to
+        // move from it. The source pile exists in `piles` (key is present) but
+        // contains no cards — exactly the code path that returns EmptySource.
+        let mut g = new_game();
+        // Tableau(0) starts with exactly 1 card; clear it to make the pile empty.
+        g.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.clear();
+        let result = g.move_cards(PileType::Tableau(0), PileType::Tableau(1), 1);
+        assert_eq!(
+            result,
+            Err(MoveError::EmptySource),
+            "moving from an empty pile must return EmptySource"
+        );
+    }
+
     // --- next_auto_complete_move ---
 
     #[test]

solitaire_core/src/pile.rs

@@ -17,7 +17,9 @@ pub enum PileType {
 /// A named collection of cards in a specific board position.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct Pile {
+    /// Which pile this is (Stock, Waste, Foundation suit, or Tableau column).
     pub pile_type: PileType,
+    /// Cards in the pile, bottom-to-top stacking order. Last element is the top card.
     pub cards: Vec<Card>,
 }
 

solitaire_core/src/scoring.rs

@@ -91,6 +91,6 @@ mod tests {
     fn time_bonus_is_capped_at_i32_max_for_huge_values() {
         // Very short elapsed time would overflow without the .min() guard.
         let bonus = compute_time_bonus(1);
-        assert!(bonus <= i32::MAX, "time bonus must fit in i32");
+        assert!(bonus >= 0, "time bonus must be non-negative after u64→i32 cast");
     }
 }

solitaire_data/Cargo.toml

@@ -1,6 +1,7 @@
 [package]
 name    = "solitaire_data"
 version.workspace = true
+license.workspace = true
 edition.workspace = true
 
 [dependencies]
@@ -12,6 +13,6 @@ chrono         = { workspace = true }
 thiserror      = { workspace = true }
 async-trait    = { workspace = true }
 dirs           = { workspace = true }
-keyring        = { workspace = true }
+keyring-core   = { workspace = true }
 reqwest        = { workspace = true }
 tokio          = { workspace = true }

solitaire_data/src/auth_tokens.rs

@@ -8,9 +8,15 @@
 //! [`TokenError::KeychainUnavailable`] — callers should fall back to prompting
 //! the user to log in again.
 //!
+//! Before calling any function in this module the application must initialise
+//! the default keyring store exactly once at startup by calling
+//! `keyring::use_native_store` (e.g. in `solitaire_app::main` before building
+//! the Bevy `App`). If no default store is set, all operations in this module
+//! will return [`TokenError::KeychainUnavailable`].
+//!
 //! # Note: no unit tests — requires live OS keychain.
 
-use keyring::Entry;
+use keyring_core::Entry;
 use thiserror::Error;
 
 /// Errors that can occur when reading or writing tokens in the OS keychain.
@@ -30,12 +36,13 @@ pub enum TokenError {
 /// Service name used to namespace all keychain entries for this application.
 const SERVICE: &str = "solitaire_quest_server";
 
-/// Map a `keyring::Error` to the appropriate `TokenError`.
+/// Map a `keyring_core::Error` to the appropriate `TokenError`.
-fn map_keyring_err(err: keyring::Error, username: &str) -> TokenError {
+fn map_keyring_err(err: keyring_core::Error, username: &str) -> TokenError {
     let msg = err.to_string();
     match err {
-        keyring::Error::NoStorageAccess(_) => TokenError::KeychainUnavailable(msg),
+        keyring_core::Error::NoStorageAccess(_) => TokenError::KeychainUnavailable(msg),
-        keyring::Error::NoEntry => TokenError::NotFound(username.to_string()),
+        keyring_core::Error::NoDefaultStore => TokenError::KeychainUnavailable(msg),
+        keyring_core::Error::NoEntry => TokenError::NotFound(username.to_string()),
         _ => TokenError::Keyring(msg),
     }
 }
@@ -88,17 +95,17 @@ pub fn load_refresh_token(username: &str) -> Result<String, TokenError> {
 pub fn delete_tokens(username: &str) -> Result<(), TokenError> {
     match Entry::new(SERVICE, &format!("{username}_access"))
         .map_err(|e| map_keyring_err(e, username))?
-        .delete_password()
+        .delete_credential()
     {
-        Ok(()) | Err(keyring::Error::NoEntry) => {}
+        Ok(()) | Err(keyring_core::Error::NoEntry) => {}
         Err(e) => return Err(map_keyring_err(e, username)),
     }
 
     match Entry::new(SERVICE, &format!("{username}_refresh"))
         .map_err(|e| map_keyring_err(e, username))?
-        .delete_password()
+        .delete_credential()
     {
-        Ok(()) | Err(keyring::Error::NoEntry) => {}
+        Ok(()) | Err(keyring_core::Error::NoEntry) => {}
         Err(e) => return Err(map_keyring_err(e, username)),
     }
 

solitaire_data/src/progress.rs

@@ -148,8 +148,7 @@ mod tests {
 
     #[test]
     fn add_xp_saturates_on_overflow() {
-        let mut p = PlayerProgress::default();
+        let mut p = PlayerProgress { total_xp: u64::MAX - 5, ..Default::default() };
-        p.total_xp = u64::MAX - 5;
         p.add_xp(100);
         assert_eq!(p.total_xp, u64::MAX);
     }

solitaire_data/src/settings.rs

@@ -40,7 +40,8 @@ pub enum Theme {
 
 /// Which sync backend the player has configured.
 ///
-/// JWT tokens for `SolitaireServer` are stored in the OS keychain via
+/// `Local` keeps all progress on-device. `SolitaireServer` syncs via the
+/// self-hosted server. JWT tokens are stored in the OS keychain via
 /// `solitaire_data::auth_tokens` — **never** in this struct.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize, Default)]
 pub enum SyncBackend {
@@ -57,10 +58,7 @@ pub enum SyncBackend {
         username: String,
         // JWT tokens are stored in the OS keychain — not here.
     },
-    /// Google Play Games Services (Android only). Selecting this on non-Android
+
-    /// platforms silently falls back to `Local` at runtime.
-    #[serde(rename = "google_play_games")]
-    GooglePlayGames,
 }
 
 /// Persistent user settings.
@@ -207,8 +205,7 @@ mod tests {
 
     #[test]
     fn adjust_sfx_volume_clamps() {
-        let mut s = Settings::default();
+        let mut s = Settings { sfx_volume: 0.5, ..Default::default() };
-        s.sfx_volume = 0.5;
         assert!((s.adjust_sfx_volume(0.3) - 0.8).abs() < 1e-6);
         assert!((s.adjust_sfx_volume(0.5) - 1.0).abs() < 1e-6);
         assert!((s.adjust_sfx_volume(-2.0) - 0.0).abs() < 1e-6);
@@ -217,8 +214,7 @@ mod tests {
 
     #[test]
     fn adjust_music_volume_clamps() {
-        let mut s = Settings::default();
+        let mut s = Settings { music_volume: 0.5, ..Default::default() };
-        s.music_volume = 0.5;
         assert!((s.adjust_music_volume(0.3) - 0.8).abs() < 1e-6);
         assert!((s.adjust_music_volume(0.5) - 1.0).abs() < 1e-6);
         assert!((s.adjust_music_volume(-2.0) - 0.0).abs() < 1e-6);
@@ -241,14 +237,10 @@ mod tests {
 
     #[test]
     fn sanitized_clamps_music_volume() {
-        let mut s = Settings::default();
+        let s = Settings { music_volume: 2.0, ..Default::default() }.sanitized();
-        s.music_volume = 2.0;
-        let s = s.sanitized();
         assert_eq!(s.music_volume, 1.0);
 
-        let mut s2 = Settings::default();
+        let s2 = Settings { music_volume: -0.5, ..Default::default() }.sanitized();
-        s2.music_volume = -0.5;
-        let s2 = s2.sanitized();
         assert_eq!(s2.music_volume, 0.0);
     }
 

solitaire_data/src/stats.rs

@@ -13,7 +13,7 @@ pub use solitaire_sync::StatsSnapshot;
 ///
 /// Import this trait alongside `StatsSnapshot` to use `update_on_win`.
 pub trait StatsExt {
-    /// Record a completed win. Updates all relevant counters and rolling averages.
+    /// Updates rolling statistics from a completed game win. Call once per `GameWonEvent`.
     fn update_on_win(&mut self, score: i32, time_seconds: u64, draw_mode: &DrawMode);
 }
 
@@ -173,8 +173,7 @@ mod tests {
 
     #[test]
     fn lifetime_score_saturates_at_u64_max() {
-        let mut s = StatsSnapshot::default();
+        let mut s = StatsSnapshot { lifetime_score: u64::MAX - 100, ..Default::default() };
-        s.lifetime_score = u64::MAX - 100;
         s.update_on_win(200, 60, &DrawMode::DrawOne);
         assert_eq!(s.lifetime_score, u64::MAX, "lifetime_score must saturate, not overflow");
     }

solitaire_data/src/sync_client.rs

@@ -364,6 +364,10 @@ impl SyncProvider for SolitaireServerClient {
 
 /// Deserialize a pull response body as [`SyncResponse`] and return its
 /// `merged` field, or map non-200 statuses to the appropriate [`SyncError`].
+///
+/// Only HTTP 401 (Unauthorized) and 403 (Forbidden) are treated as
+/// authentication errors. All other non-2xx statuses (5xx, 429, etc.) are
+/// classified as network/transport errors so the UI shows the right message.
 async fn extract_pull_body(resp: reqwest::Response) -> Result<SyncPayload, SyncError> {
     let status = resp.status();
     if status.is_success() {
@@ -372,8 +376,12 @@ async fn extract_pull_body(resp: reqwest::Response) -> Result<SyncPayload, SyncE
             .await
             .map_err(|e| SyncError::Serialization(e.to_string()))?;
         Ok(sync_resp.merged)
-    } else {
+    } 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}")))
     }
 }
 
@@ -391,14 +399,22 @@ async fn extract_leaderboard_body(resp: reqwest::Response) -> Result<Vec<Leaderb
 
 /// Deserialize a push response body as [`SyncResponse`], or map non-200
 /// statuses to the appropriate [`SyncError`].
+///
+/// Only HTTP 401 (Unauthorized) and 403 (Forbidden) are treated as
+/// authentication errors. All other non-2xx statuses (5xx, 429, etc.) are
+/// classified as network/transport errors so the UI shows the right message.
 async fn extract_push_body(resp: reqwest::Response) -> Result<SyncResponse, SyncError> {
     let status = resp.status();
     if status.is_success() {
         resp.json()
             .await
             .map_err(|e| SyncError::Serialization(e.to_string()))
-    } else {
+    } 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}")))
     }
 }
 
@@ -412,19 +428,12 @@ async fn extract_push_body(resp: reqwest::Response) -> Result<SyncResponse, Sync
 /// This is the **one** place in the codebase that matches on [`SyncBackend`]
 /// variants. All other code receives a `Box<dyn SyncProvider + Send + Sync>`
 /// and remains backend-agnostic.
-///
-/// `GooglePlayGames` is Android-only; on desktop it silently falls back to
-/// [`LocalOnlyProvider`].
 pub fn provider_for_backend(backend: &SyncBackend) -> Box<dyn SyncProvider + Send + Sync> {
     match backend {
         SyncBackend::Local => Box::new(LocalOnlyProvider),
         SyncBackend::SolitaireServer { url, username } => {
             Box::new(SolitaireServerClient::new(url.clone(), username.clone()))
         }
-        SyncBackend::GooglePlayGames => {
-            // GPGS is Android-only; fall back to no-op on desktop.
-            Box::new(LocalOnlyProvider)
-        }
     }
 }
 
@@ -470,12 +479,6 @@ mod tests {
         assert_eq!(provider.backend_name(), "local");
     }
 
-    #[test]
-    fn factory_gpgs_falls_back_to_local() {
-        let provider = provider_for_backend(&SyncBackend::GooglePlayGames);
-        assert_eq!(provider.backend_name(), "local");
-    }
-
     #[test]
     fn factory_server_returns_server_client() {
         let provider = provider_for_backend(&SyncBackend::SolitaireServer {

solitaire_data/src/weekly.rs

@@ -9,7 +9,7 @@ use solitaire_core::game_state::DrawMode;
 /// XP awarded each time a weekly goal is just completed.
 pub const WEEKLY_GOAL_XP: u64 = 75;
 
-/// What kind of game outcome counts as progress toward this goal.
+/// Discriminant for the type of weekly goal the player is working toward.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum WeeklyGoalKind {
     /// Any win counts.
@@ -22,7 +22,7 @@ pub enum WeeklyGoalKind {
     WinDrawThree,
 }
 
-/// Static metadata for a single weekly goal.
+/// Static definition of a weekly goal — the goal type, target value, and display strings.
 #[derive(Debug, Clone, Copy)]
 pub struct WeeklyGoalDef {
     pub id: &'static str,
@@ -31,7 +31,7 @@ pub struct WeeklyGoalDef {
     pub kind: WeeklyGoalKind,
 }
 
-/// Per-event facts a goal needs to decide whether it matched.
+/// Runtime snapshot of game metrics used to evaluate weekly goal progress.
 #[derive(Debug, Clone)]
 pub struct WeeklyGoalContext {
     pub time_seconds: u64,