docs: update repo URL references to corrected Rusty_Solitaire spelling

The GitHub repo was renamed from Rusty_Solitare to Rusty_Solitaire (adding the missing 'i'). The local origin remote has been updated via `git remote set-url`; this commit updates the three doc references that hardcoded the old URL. SESSION_HANDOFF.md's "Canonical remote" section now names the new URL and explains the rename for future readers, including the note that local clone directories may still be named Rusty_Solitare — that's a local-only name and works fine, only the GitHub repo URL changed. docs/SESSION_HANDOFF.md (older snapshot, unchanged otherwise) gets its single URL line corrected. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
docs: refresh SESSION_HANDOFF for session 7 UX-iteration round complete
2026-05-02 00:36:06 +00:00 · 2026-05-02 00:33:42 +00:00 · 2026-05-02 00:31:15 +00:00 · 2026-05-02 00:21:28 +00:00 · 2026-05-01 22:33:22 +00:00 · 2026-05-01 22:17:17 +00:00
238 changed files with 42786 additions and 4877 deletions
@@ -0,0 +1,31 @@
+# Project-wide cargo configuration.
+#
+# Routes every rustc invocation through `sccache` so cold rebuilds and
+# fresh checkouts (CI, new dev box, after a `cargo clean`) replay
+# previously-compiled crates from a local on-disk cache rather than
+# recompiling them. Warm incremental builds still go through cargo's
+# own `target/` cache, which dominates locally — sccache buys you the
+# big wins on cold paths.
+#
+# Requires sccache on PATH. Install it once per machine:
+#
+#   Arch     :  pacman -S sccache
+#   macOS    :  brew install sccache
+#   Cargo    :  cargo install sccache --locked
+#
+# Without sccache the build fails with "rustc-wrapper not found". To
+# bypass this config without editing the file, prepend
+# `RUSTC_WRAPPER= ` (empty value) to your cargo command:
+#
+#   RUSTC_WRAPPER= cargo build
+#
+[build]
+rustc-wrapper = "sccache"
+
+# Project-local cache so the shared dev box (or a Docker volume) keeps
+# the artefacts isolated per checkout instead of mixing them in
+# `~/.cache/sccache`. Set with `force = false` so a developer-set
+# `SCCACHE_DIR` in their shell wins — important because the sccache
+# daemon, once started, sticks with whichever directory it saw first.
+[env]
+SCCACHE_DIR = { value = ".sccache-cache", relative = true, force = false }
@@ -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
@@ -1,7 +1,9 @@
 /target
+/.sccache-cache
 *.db
 *.db-shm
 *.db-wal
 .env
 *.tmp
 data/
+.claude/
@@ -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"
+}
@@ -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)
-9. [Data Models](#9-data-models)
-10. [API Reference](#10-api-reference)
-11. [Merge Strategy](#11-merge-strategy)
-12. [Achievement System](#12-achievement-system)
-13. [Progression System](#13-progression-system)
-14. [Audio System](#14-audio-system)
-15. [Asset Pipeline](#15-asset-pipeline)
-16. [Platform Targets](#16-platform-targets)
-17. [Build & Development Guide](#17-build--development-guide)
-18. [Deployment Guide](#18-deployment-guide)
-19. [Security Model](#19-security-model)
-20. [Testing Strategy](#20-testing-strategy)
-21. [Decision Log](#21-decision-log)
+8. [Data Models](#8-data-models)
+9. [API Reference](#9-api-reference)
+10. [Merge Strategy](#10-merge-strategy)
+11. [Achievement System](#11-achievement-system)
+12. [Progression System](#12-progression-system)
+13. [Audio System](#13-audio-system)
+14. [Asset Pipeline](#14-asset-pipeline)
+15. [Platform Targets](#15-platform-targets)
+16. [Build & Development Guide](#16-build--development-guide)
+17. [Deployment Guide](#17-deployment-guide)
+18. [Security Model](#18-security-model)
+19. [Testing Strategy](#19-testing-strategy)
+20. [Decision Log](#20-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.
-
-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.
+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.

 ### 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

@@ -56,6 +51,7 @@ On Android (stretch goal), sync is enhanced with Google Play Games Services (GPG
 - **No panics in game logic.** Every state transition returns `Result<_, MoveError>`. Panics are only acceptable in startup/configuration code.
 - **One language, one repo.** The game client, sync client, shared types, and sync server are all Rust crates in a single Cargo workspace.
 - **Plugin-based Bevy architecture.** Each major feature is a Bevy `Plugin`. Systems are small and single-purpose. Cross-system communication uses Bevy `Event`s.
+- **UI-first interaction.** Every player-triggered action — new game, undo, draw, pause, open stats / settings / help / profile / leaderboard, etc. — must be reachable from a visible UI control. Keyboard shortcuts exist only as optional accelerators for power users; they are never the sole entry point. A player using only mouse or touch must be able to perform every action. New gameplay features ship with the UI control alongside the system that backs it.

 ---

@@ -72,26 +68,25 @@ solitaire_quest/
 ├── Dockerfile                  # Multi-stage server build
 ├── docker-compose.yml          # Server + Caddy reverse proxy
 │
-├── assets/                     # All runtime assets (loaded via Bevy AssetServer)
+├── assets/                     # Loaded at runtime via AssetServer (audio is embedded via include_bytes!())
 │   ├── cards/
-│   │   ├── faces/              # Card face sprites (suit + rank)
-│   │   └── backs/              # Card back designs (back_0.png … back_4.png)
-│   ├── backgrounds/            # Table backgrounds (bg_0.png … bg_4.png)
-│   ├── fonts/                  # .ttf font files
+│   │   ├── faces/{RANK}{SUIT}.png   # 52 card faces — rendered from hayeah/playing-cards-assets SVGs (MIT)
+│   │   └── backs/back_0.png – back_4.png    # back_0 = generated default back; back_1–4 are generated patterns
+│   ├── backgrounds/bg_0.png – bg_4.png      # generated textures
+│   ├── fonts/main.ttf          # FiraMono-Medium (170K, OFL)
 │   └── audio/
-│       ├── card_deal.ogg
-│       ├── card_flip.ogg
-│       ├── card_place.ogg
-│       ├── card_invalid.ogg
-│       ├── win_fanfare.ogg
-│       └── ambient_loop.ogg
+│       ├── card_deal.wav
+│       ├── card_flip.wav
+│       ├── card_place.wav
+│       ├── card_invalid.wav
+│       ├── win_fanfare.wav
+│       └── 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
 ```

@@ -135,25 +130,10 @@ 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)
-
-### `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.
+- `SyncProvider` trait — implemented by `SolitaireServerClient`

 ### `solitaire_engine`
-**Dependencies:** `bevy`, `bevy_kira_audio`, `solitaire_core`, `solitaire_data`.
+**Dependencies:** `bevy`, `kira`, `solitaire_core`, `solitaire_data`.

 All Bevy-specific code. Structured as a collection of Plugins that `solitaire_app` registers.

@@ -165,6 +145,7 @@ Owns:
 - All Bevy UI screens (Home, Stats, Achievements, Settings, Profile)
 - Audio playback systems
 - Sync status display
+- Card, background, and font asset loading via Bevy `AssetServer` (audio is the lone exception — embedded via `include_bytes!()` in `audio_plugin.rs`)

 ### `solitaire_server`
 **Dependencies:** `solitaire_sync`, `axum`, `sqlx`, `jsonwebtoken`, `bcrypt`, `tower-governor`, `tracing`, `tokio`, `dotenvy`.
@@ -223,8 +204,7 @@ SyncPlugin::on_startup()
    │  spawns AsyncComputeTask
    ▼
 solitaire_data::sync_pull()          ← dispatches to active SyncProvider
-    │                                    SolitaireServerClient  (desktop / iOS)
-    │                                    GpgsClient             (Android, future)
+    │                                    SolitaireServerClient
    ▼
 solitaire_sync::merge(local, remote)
    │
@@ -245,7 +225,7 @@ 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
 ```
@@ -256,19 +236,22 @@ Done

 ### Bevy Plugins

-| Plugin | Key | Responsibility |
+The "Shortcut" column lists optional keyboard accelerators. Every action in this table must also be reachable from a visible UI control (button, menu item, on-screen affordance) per the UI-first design principle in §1; the shortcut is a power-user convenience, not the sole entry point.
+
+| Plugin | Shortcut | Responsibility |
 |---|---|---|
 | `CardPlugin` | — | Card entity spawning, sprite management, drag-and-drop |
 | `TablePlugin` | — | Pile markers, background, layout calculation |
+| `FontPlugin` | — | Loads FiraMono-Medium via `AssetServer` at startup; 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 |
-| `AudioPlugin` | — | Sound effect and music playback via bevy_kira_audio |
+| `AudioPlugin` | — | Sound effect and music playback via kira |
 | `InputPlugin` | — | Keyboard and mouse input routing |
 | `CursorPlugin` | — | Custom cursor sprite during drag |
 | `SelectionPlugin` | — | Keyboard-driven card selection |
 | `GamePlugin` | N | Core game state resource, new-game flow, win/game-over overlays |
-| `HudPlugin` | — | Score, move counter, timer, auto-complete badge |
+| `HudPlugin` | — | Score, move counter, timer, auto-complete badge, and the top-right action button bar (Undo / Pause / Help / New Game). Each button fires the same request event the corresponding hotkey does. |
 | `StatsPlugin` | S | Stats overlay and persistence |
 | `ProgressPlugin` | — | XP/level system, persistence |
 | `AchievementPlugin` | A | Unlock evaluation, toast events, persistence |
@@ -309,6 +292,20 @@ 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 loaded via AssetServer at startup)
+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 +379,6 @@ 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 +393,6 @@ 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 +404,6 @@ 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 +490,7 @@ This ensures all players worldwide get the same challenge for a given date, rega

 ---

-## 8. Google Play Games Services (Android Future)
-
-> **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
+## 8. Data Models

 ### Core Game Models (`solitaire_core`)

@@ -677,14 +584,14 @@ 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 +634,9 @@ 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 +676,7 @@ pub fn merge(local: &SyncPayload, remote: &SyncPayload) -> SyncPayload {

 ---

-## 12. Achievement System
+## 11. Achievement System

 ### Definition Structure

@@ -814,13 +721,9 @@ 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

@@ -849,62 +752,85 @@ 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 `kira`. All sound files are `.wav`.

 | File | Trigger |
 |---|---|
-| `card_deal.ogg` | New game deal animation |
-| `card_flip.ogg` | Card flips face-up |
-| `card_place.ogg` | Valid card placement |
-| `card_invalid.ogg` | Invalid move attempt |
-| `win_fanfare.ogg` | Game won |
-| `ambient_loop.ogg` | Looping background music (restarts seamlessly) |
+| `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 |

-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.
+Volume is controlled by two independent sliders in Settings (`sfx_volume`, `music_volume`), each stored in `Settings` and applied as `kira` channel volumes.

 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 by `card_plugin::load_card_images` via `AssetServer::load()`.

-Card faces can be either:
- 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
+Backgrounds are Bevy `Sprite` entities with `Handle<Image>` from `BackgroundImageSet`. `BackgroundImageSet` is populated at startup by `table_plugin::load_background_images` via `AssetServer::load()`.

-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 loaded via `AssetServer::load("fonts/main.ttf")` at startup by `FontPlugin` and exposed as `FontResource` for use by all UI and text systems.

-### Backgrounds
+All three loaders take `Option<Res<AssetServer>>` so they degrade cleanly under `MinimalPlugins` in tests: when the server is absent, `CardImageSet`/`BackgroundImageSet` are inserted with empty handle slots and the plugins fall back to `Text2d` rank+suit overlays and solid-colour board backgrounds. The `assets/` directory must ship alongside the binary.

-`assets/backgrounds/bg_0.png` through `bg_4.png`. Same unlock gating as card backs.
+The `assets/` directory layout:

-### Fonts
+```
+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
+```

-`assets/fonts/main.ttf` — used for card rank/suit text in Bevy UI.
+### Audio
+
+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 |
-| iOS | Stretch | Self-hosted server | `cargo-mobile2`, touch input; GPGS unavailable on iOS |
+| Android | Stretch | Self-hosted server | `cargo-mobile2`, touch input |
+| 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 +891,7 @@ Add `--features bevy/dynamic_linking` during development to dramatically reduce

 ---

-## 18. Deployment Guide
+## 17. Deployment Guide

 ### Docker Compose (Recommended)

@@ -1010,7 +936,7 @@ Migrations run automatically on startup via `sqlx::migrate!()`.

 ---

-## 19. Security Model
+## 18. Security Model

 | Concern | Mitigation |
 |---|---|
@@ -1026,7 +952,7 @@ Migrations run automatically on startup via `sqlx::migrate!()`.

 ---

-## 20. Testing Strategy
+## 19. Testing Strategy

 ### Unit Tests (`solitaire_core`)

@@ -1065,12 +991,10 @@ 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 +1006,10 @@ 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 |
-| 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 |
+| `SyncProvider` trait, not `SyncBackend` match arms | `SyncPlugin` stays backend-agnostic and testable; new backends can be added without touching the plugin | 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 |
+| Card, background, and font assets loaded via `AssetServer` | Reverses the earlier embed-via-`include_bytes!()` decision: PNGs and TTFs are loaded at runtime so artwork can be swapped (e.g. alternate card backs, themed backgrounds) without a recompile, and binary size stays small. Loaders take `Option<Res<AssetServer>>` and fall back gracefully under `MinimalPlugins`. The `assets/` directory must ship alongside the binary. | 2026-04-29 |
+| Audio assets remain embedded via `include_bytes!()` | Audio files are small, change rarely, and the embedded path eliminates a class of runtime-load errors during gameplay; the asset-pipeline reversal does not extend to audio | 2026-04-29 |
+| Card art swapped from xCards (LGPL-3.0) to hayeah/playing-cards-assets (MIT) | Public-release readiness. The previous xCards art carried LGPL relinking obligations that complicate a single-binary distribution; hayeah's set derives from the public-domain `vector-playing-cards` line-art and is permissively MIT-licensed. CREDITS.md license summary collapsed to MIT + OFL-1.1. The default card back is original work in this project's midnight-purple palette. | 2026-05-01 |
+| Runtime SVG card-theme system (`CARD_PLAN.md`) | User-supplied themes need to ship SVG sources so they can rasterise at any resolution on the player's hardware; baking PNGs at build time only would lock theme installation to the developer. The pipeline (usvg → resvg → tiny-skia) rasterises once per (theme, target size) at load time and caches the resulting `Image`, so the runtime cost is paid once, not per frame. The bundled default theme ships via `embedded://`; user themes via `themes://` rooted at `user_theme_dir()`. | 2026-05-01 |
@@ -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 +47,13 @@ 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`.
+- Card faces (52 PNGs in `assets/cards/faces/`), card backs (`assets/cards/backs/back_N.png`), board backgrounds (`assets/backgrounds/bg_N.png`), and the UI font (`assets/fonts/main.ttf`) are loaded at runtime via `AssetServer::load()` and stored as `Handle<Image>`/`Handle<Font>` in the `CardImageSet`, `BackgroundImageSet`, and `FontResource` resources. The `assets/` directory must ship alongside the binary.
+- Asset-loading systems take `Option<Res<AssetServer>>` so they degrade cleanly under `MinimalPlugins` (tests). When `CardImageSet` is absent, `card_plugin` falls back to a `Text2d` rank+suit overlay; when `BackgroundImageSet` is absent, the board falls back to a solid colour.
 - 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.

@@ -77,6 +77,7 @@ cargo clippy -p solitaire_core -- -D warnings
 - Resources own shared state. Events communicate between systems. Components own per-entity data.
 - All UI screens are built with Bevy UI (`bevy::ui`). Never mix UI layout and game logic in the same system.
 - Layout is recomputed on `WindowResized` — never assume a fixed window size.
+- **UI-first.** Every player-triggered action (new game, undo, draw, pause, open stats / settings / help / profile / leaderboard, switch mode, etc.) must be reachable from a visible UI control. Keyboard shortcuts are optional accelerators — never the sole entry point. New gameplay features ship with the UI control alongside the system that backs it; do not merge a feature that is keyboard-only.

 ---

@@ -0,0 +1,112 @@
+# Credits
+
+Solitaire Quest is MIT-licensed (see [LICENSE](LICENSE)). It is built on top of
+the work of many open-source projects and a small handful of third-party
+assets. This file lists every component that ships in the binary or in the
+`assets/` directory.
+
+---
+
+## Code & Framework
+
+| Component | License | Role |
+|---|---|---|
+| [Bevy 0.18](https://bevyengine.org/) | MIT OR Apache-2.0 | Game engine, ECS, rendering, UI |
+| [kira 0.12](https://crates.io/crates/kira) | MIT OR Apache-2.0 | Audio playback (mixer, sub-tracks, looping ambient) |
+| [serde](https://crates.io/crates/serde) / [serde_json](https://crates.io/crates/serde_json) | MIT OR Apache-2.0 | Serialization for save files and the sync API |
+| [tokio](https://crates.io/crates/tokio) | MIT | Async runtime for the sync client and server |
+| [axum 0.8](https://crates.io/crates/axum) | MIT | HTTP framework for the self-hosted sync server |
+| [sqlx 0.8](https://crates.io/crates/sqlx) | MIT OR Apache-2.0 | Compile-time-checked SQLite access on the server |
+| [reqwest 0.13](https://crates.io/crates/reqwest) | MIT OR Apache-2.0 | HTTP client for the sync provider |
+| [jsonwebtoken 10](https://crates.io/crates/jsonwebtoken) | MIT | JWT issuance and validation |
+| [bcrypt 0.19](https://crates.io/crates/bcrypt) | MIT | Password hashing on the server |
+| [keyring 4](https://crates.io/crates/keyring) | MIT OR Apache-2.0 | OS keychain integration for credential storage |
+| [tower-governor 0.8](https://crates.io/crates/tower-governor) | MIT | Rate limiting on `/api/auth/*` |
+| [chrono](https://crates.io/crates/chrono) | MIT OR Apache-2.0 | Date / time handling |
+| [uuid](https://crates.io/crates/uuid) | MIT OR Apache-2.0 | User and session identifiers |
+| [thiserror](https://crates.io/crates/thiserror) | MIT OR Apache-2.0 | Error type derive |
+| [rand 0.9](https://crates.io/crates/rand) | MIT OR Apache-2.0 | Seeded shuffler in `solitaire_core` |
+| [png 0.17](https://crates.io/crates/png) | MIT OR Apache-2.0 | PNG encoder used by `solitaire_assetgen` |
+| [ab_glyph 0.2](https://crates.io/crates/ab_glyph) | Apache-2.0 | Glyph rasterization for generated card art |
+
+The full transitive dependency tree (several hundred crates) is captured in
+`Cargo.lock` and reachable via `cargo tree`. Every crate brought in is
+MIT, Apache-2.0, BSD-style, or a dual-licensed combination thereof — no
+copyleft code is statically linked into the game binary.
+
+---
+
+## Assets
+
+### Card artwork
+
+| File(s) | Source | License |
+|---|---|---|
+| `solitaire_engine/assets/themes/default/{suit}_{rank}.svg` (52 SVGs) | [hayeah/playing-cards-assets](https://github.com/hayeah/playing-cards-assets) | MIT |
+| `solitaire_engine/assets/themes/default/back.svg` | Original — Solitaire Quest | MIT (this project) |
+| `assets/cards/faces/{RANK}{SUIT}.png` (52 PNGs) | Pre-rendered from the same `playing-cards-assets` SVGs | MIT (passed through from hayeah) |
+| `assets/cards/backs/back_0.png` – `back_4.png` | Original — generated by `solitaire_assetgen::gen_art` | MIT (this project) |
+
+The face SVGs come from Howard Yeh's `playing-cards-assets` repository, which
+is itself derived from the public-domain `vector-playing-cards` Google Code
+project. The art is redistributed under the MIT license — see the upstream
+repository for the full notice. The files ship unmodified in the bundled
+default theme; user-supplied themes can override them per-installation
+through the runtime SVG theming system documented in `CARD_PLAN.md`.
+
+The default card back is original work by this project, midnight-purple
+themed to match the rest of the UI palette.
+
+### Backgrounds
+
+| File(s) | Source | License |
+|---|---|---|
+| `assets/backgrounds/bg_0.png` – `bg_4.png` | Original — generated by `solitaire_assetgen::gen_art` | MIT (this project) |
+
+### Typography
+
+| File | Source | License |
+|---|---|---|
+| `assets/fonts/main.ttf` (FiraMono-Medium) | [mozilla/Fira](https://github.com/mozilla/Fira) | SIL Open Font License 1.1 |
+
+The OFL permits redistribution and embedding in software so long as the font
+file itself is not sold standalone. The file ships unmodified.
+
+### Audio
+
+All six WAV files in `assets/audio/` are **original work** — there are no
+third-party audio samples in this project. They are synthesized
+programmatically by `solitaire_assetgen/src/bin/gen_sfx.rs`, which writes
+44.1 kHz mono 16-bit PCM WAVs using a hand-rolled WAV writer (no `hound` or
+`dasp` dependency). The synthesis stack is entirely additive: sine /
+square waves, layered harmonics, deterministic LCG noise, AR envelopes,
+and a slow LFO for the ambient track.
+
+| File | Synthesis approach |
+|---|---|
+| `card_deal.wav` | Filtered LCG noise with a sweeping low-pass cutoff for a "whoosh" |
+| `card_flip.wav` | High-passed LCG noise under a fast AR envelope |
+| `card_place.wav` | 120 Hz sine body + filtered noise click |
+| `card_invalid.wav` | Two dissonant square tones (196 Hz + 207.65 Hz) beating against each other |
+| `win_fanfare.wav` | C-major arpeggio (C5 / E5 / G5 / C6) with sine + 2nd harmonic |
+| `ambient_loop.wav` | 55 Hz fundamental with 2nd and 3rd harmonics, modulated by a 0.2 Hz LFO; loop length is chosen so the tone and LFO both complete an integer number of cycles for seamless looping |
+
+Audio files are MIT-licensed alongside the rest of this project.
+
+---
+
+## License Summary
+
+- **Project code:** MIT — see [LICENSE](LICENSE).
+- **Card face artwork (52 SVGs from hayeah/playing-cards-assets, plus the
+  pre-rendered PNGs in `assets/cards/faces/`):** MIT, redistributed
+  unmodified. The original `vector-playing-cards` line art is itself
+  public domain.
+- **FiraMono-Medium font:** SIL Open Font License 1.1, redistributed unmodified.
+- **All other assets** (backgrounds, the default `back.svg`, generated card
+  backs, every audio file) are original work covered by this project's MIT
+  license.
+
+If you redistribute Solitaire Quest, you must ship this `CREDITS.md` and the
+`LICENSE` file alongside the binary so the MIT (project + hayeah card art)
+and OFL (FiraMono) notices remain visible to end users.
@@ -5,42 +5,68 @@ 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"
-rand        = "0.8"
+thiserror   = "2"
+rand        = "0.9"
 async-trait = "0.1"
 tokio       = { version = "1", features = ["full"] }
-dirs        = "5"
-keyring     = "2"
-reqwest     = { version = "0.12", features = ["json", "rustls-tls"], default-features = false }
+dirs        = "6"
+keyring     = "4"
+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"
-kira = "0.9"
+bevy = "0.18"
+kira = "0.12"

-axum               = "0.7"
+# SVG rasterisation pipeline for the runtime card-theme system.
+# usvg parses + simplifies; resvg renders to a tiny-skia Pixmap;
+# tiny-skia provides the CPU rasteriser. All three are maintained
+# together by the resvg-rs project and version in lockstep.
+usvg      = "0.47"
+resvg     = "0.47"
+tiny-skia = "0.12"
+
+# Theme manifest format. RON keeps the file human-editable while
+# preserving Rust-style structures the importer can validate.
+ron = "0.12"
+
+# Importer-only: reads user-supplied theme zip archives, validates
+# their contents, and unpacks them into the user themes directory.
+# Default features are disabled to keep the dependency footprint small;
+# only `deflate` is needed because the importer rejects other
+# compression methods anyway (see Phase 7 spec).
+zip = { version = "8.6", default-features = false, features = ["deflate"] }
+
+# Importer-only test dependency: tests build zip archives in a
+# scratch directory so they don't pollute the real user themes path
+# on the developer's machine.
+tempfile = "3.27"
+
+axum               = "0.8"
 sqlx               = { version = "0.8", features = ["runtime-tokio-rustls", "sqlite", "macros", "migrate"] }
-jsonwebtoken       = "9"
-bcrypt             = "0.15"
-tower_governor     = "0.4"
+jsonwebtoken       = { version = "10", default-features = false, features = ["rust_crypto"] }
+bcrypt             = "0.19"
+tower_governor     = "0.8"
 tracing            = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 dotenvy            = "0.15"
@@ -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"]
@@ -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.
@@ -0,0 +1,83 @@
+# 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
+```
+
+## Credits
+
+Built on [Bevy](https://bevyengine.org/) and the wider Rust ecosystem (Tokio,
+Axum, sqlx, Serde, kira, and many more). Card faces come from
+[hayeah/playing-cards-assets](https://github.com/hayeah/playing-cards-assets)
+(MIT, derived from the public-domain `vector-playing-cards` library); the
+default card back is original work; the UI font is FiraMono-Medium (OFL).
+All audio is synthesized programmatically by this project. See
+[CREDITS.md](CREDITS.md) for the full list and license details.
+
+## License
+
+MIT — see [LICENSE](LICENSE).
@@ -0,0 +1,110 @@
+# Solitaire Quest — UX Overhaul Session Handoff
+
+**Last updated:** 2026-05-02 (session 7) — UX iteration round complete: every item from session 6's UX punch list has shipped, plus a font-fallback fix surfaced by a second-machine smoke test. Six commits on top of session 6's `c4970b1`. Direction now opens for the next round — release prep or another UX pass, the player's call.
+
+## Status at pause
+
+- **HEAD:** `655dfde`. Local master is **3 commits ahead** of `origin/master` (`f6c9166`, `f712b89`, `655dfde` unpushed; `fdb6c2e` and `95df542` already pushed).
+- **Working tree:** clean. (`CARD_PLAN.md` is untracked but intentionally so — it's a plan doc, not source.)
+- **Build:** `cargo clippy --workspace --all-targets -- -D warnings` clean.
+- **Tests:** **982 passed / 0 failed** across the workspace (+20 from session 6's 962 baseline).
+- **Tags on origin:** `v0.9.0`, `v0.10.0`. Stale local-only `v0.1.0` is still safe to `git tag -d v0.1.0`.
+
+## Where we are
+
+Session 6's UX punch list was four items. All four shipped today, plus an unrelated font-fallback fix from a second-machine smoke test.
+
+The card-theme system, HUD restructure, modal scaffold, and the four big UX feel items (foundations, drop shadows, drop highlights, stock badge) are all in. Direction is open — the deferred release-prep items (`v0.11.0` cut, README/CHANGELOG refresh, desktop packaging) are still on the table, and a fresh round of UX iteration is also available.
+
+### Design direction (unchanged)
+
+- **Tone:** Balatro — chunky readable type, theatrical hierarchy, satisfying micro-interactions.
+- **Palette:** Midnight Purple base + Balatro yellow primary + warm magenta secondary.
+- See `~/.claude/projects/-home-manage-Rusty-Solitare/memory/project_ux_overhaul_2026-04.md` (auto-memory; on a different machine, recreate this fresh from the README + ARCHITECTURE.md).
+
+### Canonical remote
+
+`github.com/funman300/Rusty_Solitaire` is the canonical repo. Always push there. (Earlier sessions used `Rusty_Solitare` — single-i typo — as the repo name; the rename to `Rusty_Solitaire` happened in session 7. Local clone directories may still be named `Rusty_Solitare`; that's just a directory name and works fine.)
+
+## Session 7 (shipped 2026-05-02)
+
+| Area | Commit | What landed |
+|---|---|---|
+| Font fallback | `fdb6c2e` | `shared_fontdb` now `include_bytes!()`s `assets/fonts/main.ttf` (FiraMono) and pins every CSS generic to `"Fira Mono"` so unmatched named families on minimal Linux installs / fresh Wayland sessions / chroots don't drop card rank/suit text. Surfaced when a second-machine pull rendered cards without glyphs. |
+| Unlock foundations | `95df542` | `PileType::Foundation(Suit)` → `Foundation(u8)` (slot 0..3). `Pile::claimed_suit()` derives the claim from the bottom card — no separate field, no claim-stuck-after-undo class of bugs. `can_place_on_foundation` drops its suit parameter. `next_auto_complete_move` prefers a slot whose claimed suit matches the candidate before falling back to the first empty slot for an Ace. Empty foundation markers render as plain placeholders (no "C/D/H/S"). HUD selection label and hint toast read `claimed_suit()` and fall through to "Foundation N" / "move to foundation" when the slot is empty. Save-format invalidation: `GameState.schema_version` bumped 1 → 2; old `game_state.json` files silently fall through to "fresh game on launch." Stats / progress / achievements / settings live in separate files and are unaffected. 9 new tests. |
+| Drop overlay | `f6c9166` | The pre-existing `update_drop_highlights` system tinted `PileMarker` sprites green for valid drops, but markers were occluded by stacked cards — invisible during real play. New `update_drop_target_overlays` spawns a soft-fill + 3 px outlined box ABOVE cards for every legal target (full fanned column for tableaux, card-sized for foundations / empty tableaux). `Z_DROP_OVERLAY = 50` sits above static cards but below `DRAG_Z = 500` so the dragged card never gets occluded. Reuses `STATE_SUCCESS` hue. The original marker-tint system is untouched. 3 new tests. |
+| Drop shadows | `f712b89` | Each `CardEntity` spawns a `CardShadow` child sprite — neutral black at 25 % alpha, sized `card_size + 4 px`, offset `(2, -3)`, local z `-0.05`. `update_card_shadows_on_drag` snaps shadows in `DragState.cards` to a lifted state (40 % alpha, `(4, -6)` offset, `(8, 8)` padding). `resize_cards_in_place` extended to keep shadows cheap on window resize. `update_card_entity`'s `despawn_related` is followed by a fresh `add_card_shadow_child` so flips / theme swaps re-attach shadows. Pure `card_shadow_params(is_dragged)` helper unit-tested. 4 new tests. |
+| Stock badge | `655dfde` | A small `·N` chip at the top-right corner of the stock pile shows the remaining count. `update_stock_count_badge` spawns a top-level world entity whose `Transform.translation` is recomputed each tick from `LayoutResource`, so window resize / theme swap don't strand it. Hides via `Visibility::Hidden` when the stock empties — the existing `↺` `StockEmptyLabel` takes over and they never co-render. `Z_STOCK_BADGE = 30` sits between cards and `Z_DROP_OVERLAY`. 4 new tests. |
+
+## Open punch list — release prep (still deferred unless player chooses now)
+
+1. **Cut `v0.11.0`** — meaningful slice since `v0.10.0`: full card-theme system (CARD_PLAN phases 1–7 + theme picker + hayeah art), HUD overhaul (band + fade), session 6's four bug fixes, and session 7's font fallback + four UX feel wins. (`git tag -d v0.1.0` first to clean up the stale local tag.)
+2. **README + CHANGELOG refresh** — README was last touched at `a6b8348` before the Settings picker shipped; doesn't mention card themes, the auto-fade, or any of session 7's UX work.
+3. **Desktop packaging** per `ARCHITECTURE.md §17`. The Arch PKGBUILD exists in `/home/manage/solitaire-quest-pkgbuild/` (separate repo, no remote yet). Pending: app icon, macOS `.icns` + notarisation cert, Windows `.ico` + Authenticode cert, AppImage recipe.
+
+## Open punch list — UX iteration (next-round candidates)
+
+The session-6 list is exhausted. Candidates for a next round, none formally requested by the player:
+
+- **Animated focus ring** (currently a static overlay; could pulse on focus change).
+- **Achievement onboarding pass** — show first-time players the achievement panel after their first win.
+- **Mode-switch keyboard shortcut** from inside the Mode Launcher (today only mouse opens it).
+- **Runtime aspect-ratio fidelity** — hayeah SVGs are ~1.45 h/w; engine layout assumes 1.4. Cards render ~3 % squashed vertically. Cosmetic.
+- **Foundation completion celebration** — when a foundation reaches its King, do a small flourish (sparkle, lift, sound). The auto-complete cascade already covers the win moment, but per-foundation closure is currently silent.
+- **Drag-cancel return animation** — illegal drops snap cards back instantly. A short ease-back tween ("springs back to where it came from") would feel more forgiving.
+
+## Card-theme system (CARD_PLAN.md, fully shipped)
+
+Seven phases landed across `b8fb3fb` → `924a1e2`. End-to-end:
+
+- **Bundled default theme** ships in the binary via `embedded://` — 52 hayeah/playing-cards-assets SVGs (MIT) + a midnight-purple `back.svg` (original work).
+- **User themes** live under `themes://` rooted at `solitaire_engine::assets::user_theme_dir()`. Drop a directory containing `theme.ron` + 53 SVG files; appears in the registry on next launch.
+- **Importer** at `solitaire_engine::theme::import_theme(zip)` validates an archive (20 MB cap, zip-slip rejection, manifest validation, every SVG round-tripped through the rasteriser) and atomically unpacks.
+- **Picker UI** in Settings → Cosmetic — one chip per registered theme; selection persists to `settings.json` as `selected_theme_id` and propagates to live sprites via `react_to_settings_theme_change` → `sync_card_image_set_with_active_theme` → `StateChangedEvent`.
+
+## Resume prompt
+
+```
+You are a senior Rust + Bevy developer working on Solitaire Quest.
+Working directory: <Rusty_Solitaire clone path on this machine — local
+directory may still be named Rusty_Solitare from earlier; that's fine>.
+Branch: master. Direction is OPEN — the session-6 UX punch list is
+fully shipped. The player will choose between cutting v0.11.0, doing
+release prep (README/CHANGELOG/packaging), or starting a new UX
+iteration round.
+
+State: HEAD=655dfde. Local master is 3 commits ahead of origin
+(f6c9166, f712b89, 655dfde unpushed; fdb6c2e and 95df542 already
+pushed). Working tree clean apart from untracked CARD_PLAN.md
+(intentional).
+Build: cargo clippy --workspace --all-targets -- -D warnings clean.
+Tests: 982 passed / 0 failed.
+
+READ FIRST (in order, before doing anything):
+  1. SESSION_HANDOFF.md  — full state, session 7 changelog, punch list
+  2. CLAUDE.md           — hard rules (UI-first, no panics, etc.)
+  3. ARCHITECTURE.md     — crate responsibilities + data flow
+  4. ~/.claude/projects/<this-project>/memory/MEMORY.md
+                         — saved feedback / project context (machine-local;
+                           may be missing on a fresh machine)
+
+DECISION TO ASK THE PLAYER FIRST:
+  A. Push the 3 unpushed commits and cut v0.11.0?
+  B. Skip the tag for now, refresh README + CHANGELOG, then tag?
+  C. Skip release prep entirely and start a new UX iteration round?
+     If C, see the session-7 next-round candidates list (animated
+     focus ring, achievement onboarding, mode-switch keyboard
+     shortcut, aspect-ratio fidelity, foundation completion flourish,
+     drag-cancel return tween).
+
+WORKFLOW NOTES:
+  - Commits use:
+      git -c user.name=funman300 -c user.email=root@vscode.infinity \
+          commit -m "..."
+  - Sub-agents stage + verify only; orchestrator commits.
+  - Every commit must pass build / clippy / test before pushing.
+  - Push to GitHub (origin) — that is the canonical remote.
+
+OPEN AT THE START: ask which of A / B / C. Don't pick unilaterally —
+this is a directional choice, not a tactical one.
+```
@@ -1,7 +1,7 @@
 # Solitaire Quest — Session Handoff

 > Last updated: 2026-04-25
-> Branch: `master` — pushed to https://git.aleshym.co/funman300/Rusty_Solitare.git
+> Branch: `master` — pushed to https://github.com/funman300/Rusty_Solitaire.git
 > Test count: **242 passing** (83 core + 60 data + 99 engine), `cargo clippy --workspace -- -D warnings` clean

 ---
@@ -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.
@@ -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.
@@ -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"
+}
@@ -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
@@ -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
@@ -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"
+}
@@ -0,0 +1,2 @@
+[toolchain]
+channel = "stable"
@@ -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 }
@@ -1,14 +1,38 @@
+use std::fs::OpenOptions;
+use std::io::Write;
+use std::time::{SystemTime, UNIX_EPOCH};
+
 use bevy::prelude::*;
+use bevy::window::{MonitorSelection, PresentMode, WindowPosition};
 use solitaire_data::{load_settings_from, provider_for_backend, settings_file_path, Settings};
 use solitaire_engine::{
-    AchievementPlugin, AnimationPlugin, AudioPlugin, AutoCompletePlugin, CardPlugin,
-    ChallengePlugin, CursorPlugin, DailyChallengePlugin, FeedbackAnimPlugin, GamePlugin,
-    HelpPlugin, HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin, OnboardingPlugin,
-    PausePlugin, ProfilePlugin, ProgressPlugin, SettingsPlugin, StatsPlugin, SyncPlugin,
-    TablePlugin, TimeAttackPlugin, WeeklyGoalsPlugin,
+    register_theme_asset_sources, AchievementPlugin, AnimationPlugin, AssetSourcesPlugin,
+    AudioPlugin, AutoCompletePlugin, CardAnimationPlugin, CardPlugin, ChallengePlugin,
+    CursorPlugin, DailyChallengePlugin, FeedbackAnimPlugin, FontPlugin, GamePlugin, HelpPlugin,
+    HomePlugin, HudPlugin, InputPlugin, LeaderboardPlugin, OnboardingPlugin, PausePlugin,
+    ProfilePlugin, ProgressPlugin, SelectionPlugin, SettingsPlugin, SplashPlugin, StatsPlugin,
+    SyncPlugin, TablePlugin, ThemePlugin, ThemeRegistryPlugin, TimeAttackPlugin, UiFocusPlugin,
+    UiModalPlugin, UiTooltipPlugin, WeeklyGoalsPlugin, WinSummaryPlugin,
 };

 fn main() {
+    // Install a panic hook that writes a crash log next to the save files
+    // before re-running the default hook (so stderr still gets the message
+    // and any debugger attached still sees the panic).
+    install_crash_log_hook();
+
+    // 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()
@@ -16,24 +40,81 @@ fn main() {
        .unwrap_or_default();
    let sync_provider = provider_for_backend(&settings.sync_backend);

-    App::new()
+    // Restore the previous window geometry if the player has one saved.
+    // Otherwise open at the platform default (1280×800, centred on the
+    // primary monitor). The window_geometry field is None on first run
+    // and after upgrading from a build that didn't persist geometry.
+    let (window_resolution, window_position) = match settings.window_geometry {
+        Some(geom) => (
+            (geom.width, geom.height).into(),
+            WindowPosition::At(IVec2::new(geom.x, geom.y)),
+        ),
+        None => (
+            (1280u32, 800u32).into(),
+            WindowPosition::Centered(MonitorSelection::Primary),
+        ),
+    };
+
+    let mut app = App::new();
+
+    // The card-theme system's `themes://` asset source must be
+    // registered *before* `DefaultPlugins` builds `AssetPlugin`,
+    // because that plugin freezes the asset-source list at build
+    // time. The matching `AssetSourcesPlugin` (added below) finishes
+    // the wiring after `DefaultPlugins` by populating the embedded
+    // default theme into Bevy's `EmbeddedAssetRegistry`.
+    register_theme_asset_sources(&mut app);
+
+    app
        .add_plugins(
-            DefaultPlugins.set(WindowPlugin {
-                primary_window: Some(Window {
-                    title: "Solitaire Quest".into(),
-                    resolution: (1280.0, 800.0).into(),
+            DefaultPlugins
+                .set(WindowPlugin {
+                    primary_window: Some(Window {
+                        title: "Solitaire Quest".into(),
+                        // X11/Wayland WM_CLASS so taskbar managers group
+                        // multiple windows of this app correctly.
+                        name: Some("solitaire-quest".into()),
+                        resolution: window_resolution,
+                        position: window_position,
+                        // AutoNoVsync prefers Mailbox (triple-buffered) and
+                        // falls back to Immediate, eliminating the vsync stall
+                        // that AutoVsync produces during continuous window
+                        // resize on X11 / Wayland. The game's frame budget is
+                        // small enough that a few stray dropped frames from
+                        // disabling vsync are imperceptible.
+                        present_mode: PresentMode::AutoNoVsync,
+                        resize_constraints: bevy::window::WindowResizeConstraints {
+                            min_width: 800.0,
+                            min_height: 600.0,
+                            ..default()
+                        },
+                        ..default()
+                    }),
+                    ..default()
+                })
+                // The `assets/` directory lives at the workspace root, but
+                // Bevy resolves `AssetPlugin::file_path` relative to the
+                // binary package's `CARGO_MANIFEST_DIR` (`solitaire_app/`).
+                // Point one level up so `cargo run -p solitaire_app` finds
+                // card faces, backs, backgrounds, and the UI font.
+                .set(bevy::asset::AssetPlugin {
+                    file_path: "../assets".to_string(),
                    ..default()
                }),
-                ..default()
-            }),
        )
+        .add_plugins(AssetSourcesPlugin)
+        .add_plugins(ThemePlugin)
+        .add_plugins(ThemeRegistryPlugin)
+        .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 +133,39 @@ fn main() {
        .add_plugins(OnboardingPlugin)
        .add_plugins(SyncPlugin::new(sync_provider))
        .add_plugins(LeaderboardPlugin)
+        .add_plugins(WinSummaryPlugin)
+        .add_plugins(UiModalPlugin)
+        .add_plugins(UiFocusPlugin)
+        .add_plugins(UiTooltipPlugin)
+        .add_plugins(SplashPlugin)
        .run();
 }
+
+/// Wraps the default panic hook with one that also appends a crash log
+/// to `<data_dir>/crash.log` (next to `settings.json`). The default hook
+/// still runs afterwards, so stderr output and debugger integration are
+/// unchanged. If the data directory is unavailable, the wrapper silently
+/// falls through — the default hook handles output either way.
+fn install_crash_log_hook() {
+    let crash_log_path = settings_file_path().and_then(|p| {
+        p.parent()
+            .map(|parent| parent.join("crash.log"))
+    });
+    let default_hook = std::panic::take_hook();
+    std::panic::set_hook(Box::new(move |info| {
+        if let Some(path) = crash_log_path.as_ref()
+            && let Ok(mut file) = OpenOptions::new()
+                .create(true)
+                .append(true)
+                .open(path)
+        {
+            // Plain unix-seconds timestamp keeps the format trivially
+            // parseable and avoids pulling in chrono just for this.
+            let secs = SystemTime::now()
+                .duration_since(UNIX_EPOCH)
+                .map_or(0, |d| d.as_secs());
+            let _ = writeln!(file, "----- t={secs} -----\n{info}\n");
+        }
+        default_hook(info);
+    }));
+}
@@ -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"
@@ -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.");
+}
@@ -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 {
-        let samples = gen();
+    for (name, make) in &effects {
+        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)
 // ---------------------------------------------------------------------------
@@ -1,10 +1,10 @@
 [package]
 name    = "solitaire_core"
 version.workspace = true
+license.workspace = true
 edition.workspace = true

 [dependencies]
 serde     = { workspace = true }
-chrono    = { workspace = true }
 thiserror = { workspace = true }
 rand      = { workspace = true }
@@ -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();
@@ -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,
 }

@@ -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>,
 }

@@ -1,6 +1,6 @@
 use std::collections::{HashMap, VecDeque};
 use serde::{Deserialize, Serialize};
-use crate::card::{Card, Suit};
+use crate::card::Card;
 use crate::deck::{deal_klondike, Deck};
 use crate::error::MoveError;
 use crate::pile::{Pile, PileType};
@@ -9,6 +9,20 @@ use crate::scoring::{compute_time_bonus as scoring_time_bonus, score_move, score

 const MAX_UNDO_STACK: usize = 64;

+/// Save-file schema version for `GameState`. Increment when the on-disk
+/// representation changes incompatibly so `load_game_state_from` can refuse
+/// older formats and start the player on a fresh game.
+///
+/// History:
+/// - v1: `Foundation(Suit)` keys.
+/// - v2 (current): `Foundation(u8)` slot keys; claimed suit derived from the
+///   bottom card of the pile.
+pub const GAME_STATE_SCHEMA_VERSION: u32 = 2;
+
+/// Default value for `GameState::schema_version` when deserialising older
+/// save files that pre-date the field.
+fn schema_v1() -> u32 { 1 }
+
 /// Serialize `HashMap<PileType, Pile>` as a `Vec` of `(key, value)` pairs so
 /// that JSON (which requires string map keys) round-trips correctly.
 mod pile_map_serde {
@@ -30,7 +44,9 @@ 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 +62,13 @@ 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 +84,26 @@ 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`.
@@ -84,6 +112,11 @@ pub struct GameState {
    /// Used by the `comeback` achievement condition.
    #[serde(default)]
    pub recycle_count: u32,
+    /// Save-file schema version. Defaults to `1` for older files that pre-date
+    /// the field. The loader refuses any value other than
+    /// [`GAME_STATE_SCHEMA_VERSION`].
+    #[serde(default = "schema_v1")]
+    pub schema_version: u32,
    undo_stack: VecDeque<StateSnapshot>,
 }

@@ -102,8 +135,8 @@ impl GameState {
        let mut piles: HashMap<PileType, Pile> = HashMap::new();
        piles.insert(PileType::Stock, stock);
        piles.insert(PileType::Waste, Pile::new(PileType::Waste));
-        for suit in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades] {
-            piles.insert(PileType::Foundation(suit), Pile::new(PileType::Foundation(suit)));
+        for slot in 0..4_u8 {
+            piles.insert(PileType::Foundation(slot), Pile::new(PileType::Foundation(slot)));
        }
        for (i, pile) in tableau.into_iter().enumerate() {
            piles.insert(PileType::Tableau(i), pile);
@@ -121,6 +154,7 @@ impl GameState {
            is_auto_completable: false,
            undo_count: 0,
            recycle_count: 0,
+            schema_version: GAME_STATE_SCHEMA_VERSION,
            undo_stack: VecDeque::new(),
        }
    }
@@ -173,6 +207,7 @@ impl GameState {
                stock.cards.push(card);
            }
            self.recycle_count = self.recycle_count.saturating_add(1);
+            self.move_count += 1;
            return Ok(());
        }

@@ -232,14 +267,14 @@ impl GameState {
            let bottom_card = from_pile.cards[start].clone();

            match &to {
-                PileType::Foundation(suit) => {
+                PileType::Foundation(_) => {
                    if count != 1 {
                        return Err(MoveError::RuleViolation(
                            "only one card can move to foundation at a time".into(),
                        ));
                    }
                    let dest = self.piles.get(&to).ok_or(MoveError::InvalidDestination)?;
-                    if !can_place_on_foundation(&bottom_card, dest, *suit) {
+                    if !can_place_on_foundation(&bottom_card, dest) {
                        return Err(MoveError::RuleViolation("invalid foundation placement".into()));
                    }
                }
@@ -274,10 +309,9 @@ 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);
@@ -318,15 +352,13 @@ impl GameState {
        Ok(())
    }

-    /// Returns `true` when all four foundations each contain 13 cards.
+    /// Returns `true` when all four foundation slots each contain 13 cards.
    pub fn check_win(&self) -> bool {
-        [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades]
-            .iter()
-            .all(|&suit| {
-                self.piles
-                    .get(&PileType::Foundation(suit))
-                    .is_some_and(|p| p.cards.len() == 13)
-            })
+        (0..4_u8).all(|slot| {
+            self.piles
+                .get(&PileType::Foundation(slot))
+                .is_some_and(|p| p.cards.len() == 13)
+        })
    }

    /// Returns `true` when stock and waste are empty and all tableau cards are face-up.
@@ -352,17 +384,47 @@ 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;
        }
-        let suits = [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades];
        for i in 0..7 {
            let tableau = PileType::Tableau(i);
            if let Some(card) = self.piles[&tableau].cards.last() {
-                for &suit in &suits {
-                    let foundation = PileType::Foundation(suit);
-                    if can_place_on_foundation(card, &self.piles[&foundation], suit) {
+                // Prefer the slot that already claims this card's suit so
+                // Aces don't sometimes land in slot 0 and then leave the
+                // matching suit-claimed slot empty.
+                let mut candidate: Option<u8> = None;
+                let mut empty_slot: Option<u8> = None;
+                for slot in 0..4_u8 {
+                    let foundation = PileType::Foundation(slot);
+                    let pile = &self.piles[&foundation];
+                    if pile.cards.is_empty() {
+                        if empty_slot.is_none() {
+                            empty_slot = Some(slot);
+                        }
+                    } else if pile.claimed_suit() == Some(card.suit) {
+                        candidate = Some(slot);
+                        break;
+                    }
+                }
+                let target_slot = candidate.or_else(|| {
+                    // Only fall back to an empty slot if the card is an Ace,
+                    // which is the only rank that can claim an empty slot.
+                    if card.rank.value() == 1 { empty_slot } else { None }
+                });
+                if let Some(slot) = target_slot {
+                    let foundation = PileType::Foundation(slot);
+                    if can_place_on_foundation(card, &self.piles[&foundation]) {
                        return Some((tableau, foundation));
                    }
                }
@@ -380,7 +442,7 @@ impl GameState {
 #[cfg(test)]
 mod tests {
    use super::*;
-    use crate::card::{Card, Rank};
+    use crate::card::{Card, Rank, Suit};

    fn new_game() -> GameState {
        GameState::new(42, DrawMode::DrawOne)
@@ -411,8 +473,8 @@ mod tests {
    #[test]
    fn new_game_foundations_are_empty() {
        let g = new_game();
-        for suit in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades] {
-            assert!(g.piles[&PileType::Foundation(suit)].cards.is_empty());
+        for slot in 0..4_u8 {
+            assert!(g.piles[&PileType::Foundation(slot)].cards.is_empty());
        }
    }

@@ -562,6 +624,24 @@ 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
@@ -621,7 +701,7 @@ mod tests {
        ];
        let result = g.move_cards(
            PileType::Tableau(0),
-            PileType::Foundation(Suit::Clubs),
+            PileType::Foundation(0),
            2,
        );
        assert!(
@@ -665,8 +745,9 @@ mod tests {
    #[test]
    fn win_detection_all_foundations_complete() {
        let mut g = new_game();
-        for suit in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades] {
-            let f = g.piles.get_mut(&PileType::Foundation(suit)).unwrap();
+        let suits = [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades];
+        for (slot, suit) in suits.into_iter().enumerate() {
+            let f = g.piles.get_mut(&PileType::Foundation(slot as u8)).unwrap();
            f.cards.clear();
            for rank in [
                Rank::Ace, Rank::Two, Rank::Three, Rank::Four, Rank::Five,
@@ -949,6 +1030,24 @@ 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]
@@ -980,7 +1079,8 @@ mod tests {

        let mv = g.next_auto_complete_move().expect("should find a move");
        assert_eq!(mv.0, PileType::Tableau(0));
-        assert_eq!(mv.1, PileType::Foundation(Suit::Clubs));
+        // Slot 0 is the first empty foundation; the Ace lands there.
+        assert_eq!(mv.1, PileType::Foundation(0));
    }

    #[test]
@@ -990,4 +1090,143 @@ mod tests {
        g.is_won = true;
        assert!(g.next_auto_complete_move().is_none());
    }
+
+    // --- Slot-based foundation behaviour (refactor coverage) ---
+
+    /// Aces land in the first empty slot regardless of suit, and successive
+    /// Aces fan out across slots 0, 1, 2, 3 in deterministic order.
+    #[test]
+    fn any_ace_lands_in_first_empty_foundation() {
+        let mut g = new_game();
+        // Clear stock/waste/tableau so we can hand-construct moves directly.
+        g.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        g.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        for i in 0..7 {
+            g.piles.get_mut(&PileType::Tableau(i)).unwrap().cards.clear();
+        }
+        // Place an Ace of Clubs on tableau 0; move it to slot 0.
+        g.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.push(Card {
+            id: 1, suit: Suit::Clubs, rank: Rank::Ace, face_up: true,
+        });
+        g.move_cards(PileType::Tableau(0), PileType::Foundation(0), 1).unwrap();
+        // Now place an Ace of Spades on tableau 0 and move it to slot 1.
+        g.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.push(Card {
+            id: 2, suit: Suit::Spades, rank: Rank::Ace, face_up: true,
+        });
+        g.move_cards(PileType::Tableau(0), PileType::Foundation(1), 1).unwrap();
+
+        assert_eq!(g.piles[&PileType::Foundation(0)].claimed_suit(), Some(Suit::Clubs));
+        assert_eq!(g.piles[&PileType::Foundation(1)].claimed_suit(), Some(Suit::Spades));
+    }
+
+    /// `Pile::claimed_suit` reads the bottom card's suit on a populated
+    /// foundation slot, regardless of which slot index the pile occupies.
+    #[test]
+    fn claimed_suit_is_derived_from_bottom_card() {
+        let mut g = new_game();
+        g.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        g.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        for i in 0..7 {
+            g.piles.get_mut(&PileType::Tableau(i)).unwrap().cards.clear();
+        }
+        g.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.push(Card {
+            id: 50, suit: Suit::Hearts, rank: Rank::Ace, face_up: true,
+        });
+        g.move_cards(PileType::Tableau(0), PileType::Foundation(2), 1).unwrap();
+
+        assert_eq!(
+            g.piles[&PileType::Foundation(2)].claimed_suit(),
+            Some(Suit::Hearts)
+        );
+    }
+
+    /// Undoing the only card from a foundation slot drops the claimed suit;
+    /// the slot then accepts a different Ace.
+    #[test]
+    fn foundation_claim_drops_when_emptied_via_undo() {
+        let mut g = new_game();
+        g.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        g.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        for i in 0..7 {
+            g.piles.get_mut(&PileType::Tableau(i)).unwrap().cards.clear();
+        }
+        g.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.push(Card {
+            id: 1, suit: Suit::Hearts, rank: Rank::Ace, face_up: true,
+        });
+        g.move_cards(PileType::Tableau(0), PileType::Foundation(0), 1).unwrap();
+        assert_eq!(g.piles[&PileType::Foundation(0)].claimed_suit(), Some(Suit::Hearts));
+
+        g.undo().unwrap();
+        assert!(g.piles[&PileType::Foundation(0)].cards.is_empty());
+        assert!(g.piles[&PileType::Foundation(0)].claimed_suit().is_none());
+
+        // A different Ace can now claim slot 0.
+        let t0 = g.piles.get_mut(&PileType::Tableau(0)).unwrap();
+        t0.cards.clear();
+        t0.cards.push(Card { id: 2, suit: Suit::Spades, rank: Rank::Ace, face_up: true });
+        g.move_cards(PileType::Tableau(0), PileType::Foundation(0), 1).unwrap();
+        assert_eq!(g.piles[&PileType::Foundation(0)].claimed_suit(), Some(Suit::Spades));
+    }
+
+    /// Successive Aces from the waste pile distribute across slots 0..=3 in
+    /// order — the player picks the slot, but `move_cards` accepts any
+    /// empty-slot placement for an Ace.
+    #[test]
+    fn multiple_aces_distribute_across_slots() {
+        let mut g = new_game();
+        g.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        g.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        for i in 0..7 {
+            g.piles.get_mut(&PileType::Tableau(i)).unwrap().cards.clear();
+        }
+        let aces = [
+            (Suit::Clubs, 10),
+            (Suit::Diamonds, 11),
+            (Suit::Hearts, 12),
+            (Suit::Spades, 13),
+        ];
+        for (slot, (suit, id)) in aces.iter().enumerate() {
+            g.piles.get_mut(&PileType::Waste).unwrap().cards.push(Card {
+                id: *id, suit: *suit, rank: Rank::Ace, face_up: true,
+            });
+            g.move_cards(PileType::Waste, PileType::Foundation(slot as u8), 1).unwrap();
+        }
+        for (slot, (suit, _)) in aces.iter().enumerate() {
+            assert_eq!(
+                g.piles[&PileType::Foundation(slot as u8)].claimed_suit(),
+                Some(*suit),
+                "slot {slot} should claim {suit:?}",
+            );
+        }
+    }
+
+    /// Auto-complete prefers the foundation slot whose claimed suit matches
+    /// the candidate card's suit, even if an empty slot exists at a lower
+    /// index.
+    #[test]
+    fn next_auto_complete_move_picks_slot_with_matching_claim() {
+        let mut g = new_game();
+        g.piles.get_mut(&PileType::Stock).unwrap().cards.clear();
+        g.piles.get_mut(&PileType::Waste).unwrap().cards.clear();
+        for i in 0..7 {
+            g.piles.get_mut(&PileType::Tableau(i)).unwrap().cards.clear();
+        }
+        // Slot 0 is empty; slot 1 already claims Hearts via Ace of Hearts.
+        g.piles.get_mut(&PileType::Foundation(1)).unwrap().cards.push(Card {
+            id: 1, suit: Suit::Hearts, rank: Rank::Ace, face_up: true,
+        });
+        // Tableau 0 holds the 2 of Hearts to play.
+        g.piles.get_mut(&PileType::Tableau(0)).unwrap().cards.push(Card {
+            id: 2, suit: Suit::Hearts, rank: Rank::Two, face_up: true,
+        });
+        g.is_auto_completable = true;
+
+        let mv = g.next_auto_complete_move().expect("auto-complete must find slot 1");
+        assert_eq!(mv.0, PileType::Tableau(0));
+        assert_eq!(
+            mv.1,
+            PileType::Foundation(1),
+            "must target the Hearts-claimed slot, not the empty slot 0",
+        );
+    }
 }
@@ -8,8 +8,10 @@ pub enum PileType {
    Stock,
    /// The face-up discard pile drawn to.
    Waste,
-    /// One of the four suit-ordered foundation piles.
-    Foundation(Suit),
+    /// One of the four foundation slots (0..=3). The claimed suit, if any,
+    /// is derived from the bottom card of the pile (always an Ace by
+    /// construction).
+    Foundation(u8),
    /// One of the seven tableau columns (0–6).
    Tableau(usize),
 }
@@ -17,7 +19,9 @@ 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 slot, or Tableau column).
    pub pile_type: PileType,
+    /// Cards in the pile, bottom-to-top stacking order. Last element is the top card.
    pub cards: Vec<Card>,
 }

@@ -31,6 +35,16 @@ impl Pile {
    pub fn top(&self) -> Option<&Card> {
        self.cards.last()
    }
+
+    /// For foundation piles: returns `Some(suit)` once at least one card has
+    /// landed (the bottom card is always an Ace of the claimed suit).
+    /// Returns `None` for empty foundations or non-foundation piles.
+    pub fn claimed_suit(&self) -> Option<Suit> {
+        match self.pile_type {
+            PileType::Foundation(_) => self.cards.first().map(|c| c.suit),
+            _ => None,
+        }
+    }
 }

 #[cfg(test)]
@@ -59,12 +73,33 @@ mod tests {
    }

    #[test]
-    fn pile_type_foundation_uses_suit() {
-        assert_ne!(PileType::Foundation(Suit::Hearts), PileType::Foundation(Suit::Spades));
+    fn pile_type_foundation_uses_slot_index() {
+        assert_ne!(PileType::Foundation(0), PileType::Foundation(3));
    }

    #[test]
    fn pile_type_tableau_uses_index() {
        assert_ne!(PileType::Tableau(0), PileType::Tableau(6));
    }
+
+    #[test]
+    fn claimed_suit_is_none_for_empty_foundation() {
+        let pile = Pile::new(PileType::Foundation(0));
+        assert!(pile.claimed_suit().is_none());
+    }
+
+    #[test]
+    fn claimed_suit_is_none_for_non_foundation() {
+        let mut pile = Pile::new(PileType::Tableau(0));
+        pile.cards.push(Card { id: 0, suit: Suit::Hearts, rank: Rank::Ace, face_up: true });
+        assert!(pile.claimed_suit().is_none());
+    }
+
+    #[test]
+    fn claimed_suit_returns_bottom_card_suit() {
+        let mut pile = Pile::new(PileType::Foundation(2));
+        pile.cards.push(Card { id: 0, suit: Suit::Hearts, rank: Rank::Ace, face_up: true });
+        pile.cards.push(Card { id: 1, suit: Suit::Hearts, rank: Rank::Two, face_up: true });
+        assert_eq!(pile.claimed_suit(), Some(Suit::Hearts));
+    }
 }
@@ -1,16 +1,18 @@
-use crate::card::{Card, Suit};
+use crate::card::Card;
 use crate::pile::Pile;

-/// Returns `true` if `card` can be placed on `pile` as the next card in the foundation for `suit`.
+/// Returns `true` if `card` can be placed on the foundation `pile`.
 ///
-/// Foundation rules: same suit, Ace starts, each subsequent card is one rank higher.
-pub fn can_place_on_foundation(card: &Card, pile: &Pile, suit: Suit) -> bool {
-    if card.suit != suit {
-        return false;
-    }
+/// Foundation rules:
+/// - When the pile is empty, any Ace is accepted; the placed Ace's suit
+///   becomes the pile's claimed suit (derived from the bottom card via
+///   [`Pile::claimed_suit`](crate::pile::Pile::claimed_suit)).
+/// - When the pile is non-empty, the next card must match the top card's
+///   suit and be exactly one rank higher.
+pub fn can_place_on_foundation(card: &Card, pile: &Pile) -> bool {
    match pile.cards.last() {
        None => card.rank.value() == 1,
-        Some(top) => card.rank.value() == top.rank.value() + 1,
+        Some(top) => card.suit == top.suit && card.rank.value() == top.rank.value() + 1,
    }
 }

@@ -45,37 +47,46 @@ mod tests {
    // Foundation tests
    #[test]
    fn foundation_ace_on_empty_is_valid() {
-        let c = card(Suit::Hearts, Rank::Ace);
-        let p = Pile::new(PileType::Foundation(Suit::Hearts));
-        assert!(can_place_on_foundation(&c, &p, Suit::Hearts));
+        // Every suit's Ace must land on an empty foundation slot regardless of
+        // its slot index; the slot claims the suit only after the Ace lands.
+        for suit in [Suit::Clubs, Suit::Diamonds, Suit::Hearts, Suit::Spades] {
+            let c = card(suit, Rank::Ace);
+            let p = Pile::new(PileType::Foundation(0));
+            assert!(
+                can_place_on_foundation(&c, &p),
+                "Ace of {suit:?} must land on empty slot 0",
+            );
+        }
    }

    #[test]
    fn foundation_non_ace_on_empty_is_invalid() {
        let c = card(Suit::Hearts, Rank::Two);
-        let p = Pile::new(PileType::Foundation(Suit::Hearts));
-        assert!(!can_place_on_foundation(&c, &p, Suit::Hearts));
+        let p = Pile::new(PileType::Foundation(0));
+        assert!(!can_place_on_foundation(&c, &p));
    }

    #[test]
    fn foundation_two_on_ace_same_suit_is_valid() {
        let c = card(Suit::Clubs, Rank::Two);
-        let p = pile_with(PileType::Foundation(Suit::Clubs), vec![card(Suit::Clubs, Rank::Ace)]);
-        assert!(can_place_on_foundation(&c, &p, Suit::Clubs));
+        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Clubs, Rank::Ace)]);
+        assert!(can_place_on_foundation(&c, &p));
    }

    #[test]
-    fn foundation_wrong_suit_is_invalid() {
-        let c = card(Suit::Hearts, Rank::Ace);
-        let p = Pile::new(PileType::Foundation(Suit::Spades));
-        assert!(!can_place_on_foundation(&c, &p, Suit::Spades));
+    fn foundation_second_card_must_match_claimed_suit() {
+        // Place Ace of Hearts on slot 0, then attempt 2 of Spades — rejected
+        // because the slot's claimed suit is Hearts after the Ace lands.
+        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Hearts, Rank::Ace)]);
+        let c = card(Suit::Spades, Rank::Two);
+        assert!(!can_place_on_foundation(&c, &p));
    }

    #[test]
    fn foundation_skipping_rank_is_invalid() {
        let c = card(Suit::Diamonds, Rank::Three);
-        let p = pile_with(PileType::Foundation(Suit::Diamonds), vec![card(Suit::Diamonds, Rank::Ace)]);
-        assert!(!can_place_on_foundation(&c, &p, Suit::Diamonds));
+        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Diamonds, Rank::Ace)]);
+        assert!(!can_place_on_foundation(&c, &p));
    }

    // Tableau tests
@@ -125,16 +136,16 @@ mod tests {
    fn foundation_king_on_queen_completes_suit() {
        // The last card placed to complete a foundation is always King on Queen.
        let c = card(Suit::Spades, Rank::King);
-        let p = pile_with(PileType::Foundation(Suit::Spades), vec![card(Suit::Spades, Rank::Queen)]);
-        assert!(can_place_on_foundation(&c, &p, Suit::Spades));
+        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Spades, Rank::Queen)]);
+        assert!(can_place_on_foundation(&c, &p));
    }

    #[test]
    fn foundation_king_wrong_suit_is_invalid() {
-        // King of Hearts cannot go on a Spades foundation even if rank matches.
+        // King of Hearts cannot go on a Spades-claimed foundation even if rank matches.
        let c = card(Suit::Hearts, Rank::King);
-        let p = pile_with(PileType::Foundation(Suit::Spades), vec![card(Suit::Spades, Rank::Queen)]);
-        assert!(!can_place_on_foundation(&c, &p, Suit::Spades));
+        let p = pile_with(PileType::Foundation(0), vec![card(Suit::Spades, Rank::Queen)]);
+        assert!(!can_place_on_foundation(&c, &p));
    }

    #[test]
@@ -33,12 +33,11 @@ pub fn compute_time_bonus(elapsed_seconds: u64) -> i32 {
 #[cfg(test)]
 mod tests {
    use super::*;
-    use crate::card::Suit;

    #[test]
    fn move_to_foundation_scores_ten() {
-        assert_eq!(score_move(&PileType::Waste, &PileType::Foundation(Suit::Hearts)), 10);
-        assert_eq!(score_move(&PileType::Tableau(0), &PileType::Foundation(Suit::Clubs)), 10);
+        assert_eq!(score_move(&PileType::Waste, &PileType::Foundation(2)), 10);
+        assert_eq!(score_move(&PileType::Tableau(0), &PileType::Foundation(0)), 10);
    }

    #[test]
@@ -74,7 +73,7 @@ mod tests {
    #[test]
    fn non_waste_to_tableau_scores_zero() {
        // Foundation → Tableau is impossible in practice but must score 0.
-        assert_eq!(score_move(&PileType::Foundation(Suit::Clubs), &PileType::Tableau(0)), 0);
+        assert_eq!(score_move(&PileType::Foundation(0), &PileType::Tableau(0)), 0);
        // Tableau → Tableau (restack) scores 0.
        assert_eq!(score_move(&PileType::Tableau(1), &PileType::Tableau(2)), 0);
    }
@@ -91,6 +90,6 @@ 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");
    }
 }
@@ -1,6 +1,7 @@
 [package]
 name    = "solitaire_data"
 version.workspace = true
+license.workspace = true
 edition.workspace = true

 [dependencies]
@@ -12,6 +13,15 @@ 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 }
+
+[dev-dependencies]
+solitaire_server = { path = "../solitaire_server" }
+solitaire_sync   = { workspace = true }
+axum             = { workspace = true }
+sqlx             = { workspace = true }
+jsonwebtoken     = { workspace = true }
+uuid             = { workspace = true }
+chrono           = { workspace = true }
@@ -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 +36,14 @@ 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`.
-fn map_keyring_err(err: keyring::Error, username: &str) -> TokenError {
+/// Map a `keyring_core::Error` to the appropriate `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::Error::NoEntry => TokenError::NotFound(username.to_string()),
+        keyring_core::Error::NoStorageAccess(_) | keyring_core::Error::NoDefaultStore => {
+            TokenError::KeychainUnavailable(msg)
+        }
+        keyring_core::Error::NoEntry => TokenError::NotFound(username.to_string()),
        _ => TokenError::Keyring(msg),
    }
 }
@@ -88,17 +96,17 @@ 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)),
    }

--- a/Show More
+++ b/Show More