docs: cut v0.20.0 — Terminal design system + Android persistence

Promotes the [Unreleased] section to [0.20.0] dated 2026-05-07
and opens a fresh empty [Unreleased]. The cycle's two through-
lines:

- **Terminal visual-identity port.** ui_theme token system
  (0d477ac) is load-bearing; downstream chrome migrations cover
  the modal scaffold, gameplay-feedback layer (ceec4fc), toasts
  with a new ToastVariant enum (a137607), table chrome (651f406),
  card chrome (d752870), splash cursor (cdcadda), and final
  hint-source / dest pairing (9891ae4). Card-face / suit / card-
  back palette intentionally NOT migrated — those track PNG
  artwork that hasn't been regenerated yet. The 24 Stitch-rendered
  mockups and design-system.md spec landed in fa7f98a.
- **Android persistence shim.** solitaire_data::data_dir
  routes through a per-platform shim (4b51e50) closing the
  CLAUDE.md §10 dirs::data_dir() = None pitfall on Android.
  Settings, stats, achievements, replays, game-state, time-attack
  sessions, and user themes now persist on a real APK.

Also closes three v0.19.0 punch-list candidates that landed
earlier in the cycle (pull_failure flake at 67c150b, smart-window-
size opt-out at e1b8766, Shareable badge at 9b065e5).

Tests: 1176 passing / 0 failing (six new this cycle: ui_theme
invariant guards, toast-variant-border-mapping, palette-tracking
guards on MARKER_VALID / HINT_PILE_HIGHLIGHT_COLOUR /
RIGHT_CLICK_HIGHLIGHT_COLOUR / toast-border distinctness).

SESSION_HANDOFF.md refreshed: HEAD pointer, test count, the
v0.20.0 changelog summary, the open punch list (Phase Android
runtime gaps, visual-identity follow-ups including the artwork
regeneration item), the updated design-direction box (was
Midnight Purple + Balatro yellow; now base16-eighties Terminal),
and a refreshed Resume Prompt offering A–F next-step options.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.gitignore

@@ -1,4 +1,5 @@
 /target
+/.sccache-cache
 *.db
 *.db-shm
 *.db-wal

.sqlx/query-3a9bd2e51b2389da5b7e85f26806fcffa896748e0b589d216cf60827fc3857a9.json

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

.sqlx/query-5bc1984044bc792c2e9577a159ca22789469df14cb25144451f37e8cdad8165c.json

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

.sqlx/query-6a36a96faa9d9b423aae3b72b0c049a1489b67ca2361581b2300bb4ee0bc9e2f.json

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

ARCHITECTURE.md

@@ -47,11 +47,11 @@ Solitaire Quest is a cross-platform Klondike Solitaire game written in Rust, tar
 ### Design Principles
 
 - **Offline first.** The local file is always the source of truth. Sync is additive, never destructive.
-- **Pure core.** All game logic lives in a dependency-free Rust crate with no Bevy, no network, and no I/O. This keeps it fully unit-testable and portable.
-- **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.
 
+Pure-core, no-panics-in-game-logic, and UI-first-interaction constraints are enforced by CLAUDE.md §2.1, §2.3, and §3.3 respectively — those are the canonical statements; this file describes the design that motivates them.
+
 ---
 
 ## 2. Workspace Structure
@@ -67,11 +67,11 @@ solitaire_quest/
 ├── Dockerfile                  # Multi-stage server build
 ├── docker-compose.yml          # Server + Caddy reverse proxy
 │
-├── assets/                     # Assets embedded at compile time via include_bytes!()
+├── assets/                     # Loaded at runtime via AssetServer (audio is embedded via include_bytes!())
 │   ├── cards/
-│   │   ├── faces/{rank}_{suit}.png  # 52 individual card faces (120×168, generated by solitaire_assetgen)
+│   │   ├── faces/{RANK}{SUIT}.png   # 52 card faces — rendered from hayeah/playing-cards-assets SVGs (MIT)
-│   │   └── backs/back_0.png – back_4.png    # placeholder patterns
+│   │   └── 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      # placeholder textures
+│   ├── backgrounds/bg_0.png – bg_4.png      # generated textures
 │   ├── fonts/main.ttf          # FiraMono-Medium (170K, OFL)
 │   └── audio/
 │       ├── card_deal.wav
@@ -132,7 +132,7 @@ Owns:
 - `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.
 
@@ -144,7 +144,7 @@ Owns:
 - All Bevy UI screens (Home, Stats, Achievements, Settings, Profile)
 - Audio playback systems
 - Sync status display
-- Card, background, and font asset loading (embedded via `include_bytes!()` — no `AssetServer` dependency)
+- 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`.
@@ -235,20 +235,22 @@ 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` | — | Embeds FiraMono-Medium font at compile time; exposes `FontResource` handle |
+| `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 |
@@ -296,7 +298,7 @@ struct CardImageSet {
     backs: [Handle<Image>; 5],       // indexed by selected_card_back setting
 }
 
-// Project-wide font handle (FiraMono-Medium embedded at compile time)
+// Project-wide font handle (FiraMono-Medium loaded via AssetServer at startup)
 struct FontResource(Handle<Font>);
 
 // Pre-loaded background PNG handles
@@ -713,11 +715,14 @@ pub struct AchievementDef {
 | `speed_and_skill` | ??? | Win < 90s without undo | Yes | Card back #4 |
 | `comeback` | ??? | Win after 3+ stock recycles | Yes | Background #4 |
 | `zen_winner` | ??? | Win in Zen Mode | Yes | Badge |
+| `cinephile` | Cinephile | Watch a saved replay all the way through | No | — |
 
 ### Evaluation Timing
 
 Achievement conditions are evaluated by `AchievementPlugin` on every `GameWonEvent` and `StateChangedEvent`. The plugin calls `solitaire_core::check_achievements()` which returns a `Vec<AchievementDef>` of newly unlocked achievements. The plugin then fires `AchievementUnlockedEvent` for each, which the toast and persistence systems handle independently.
 
+A small number of achievements are *event-driven* rather than condition-driven: their `AchievementDef::condition` always returns `false` and their unlock is written from a dedicated observer system instead. `cinephile` is the canonical example — it unlocks when `ReplayPlaybackState` transitions from `Playing` to `Completed` (a saved replay watched to its natural end). The Stop button transitions `Playing → Inactive` directly without entering `Completed`, so manual aborts do not unlock the achievement.
+
 ---
 
 ## 12. Progression System
@@ -751,7 +756,7 @@ Levels 11+:   level = 10 + floor((total_xp - 5000) / 1000)
 
 ## 13. Audio System
 
-Audio uses `bevy_kira_audio`. All sound files are `.wav`.
+Audio uses `kira`. All sound files are `.wav`.
 
 | File | Trigger |
 |---|---|
@@ -762,7 +767,7 @@ Audio uses `bevy_kira_audio`. All sound files are `.wav`.
 | `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.
 
@@ -772,11 +777,13 @@ Audio systems listen for Bevy events and never block the game thread.
 
 ### Rendering approach
 
-Cards are Bevy `Sprite` entities with `Handle<Image>` from `CardImageSet`. Face-up cards use one of 52 individual face PNGs selected by `faces[suit][rank]` — rank and suit are baked into each image and no `Text2d` overlay is spawned. Face-down cards use `backs/back_N.png` indexed by `settings.selected_card_back`. `Text2d` labels are only used as a fallback when `CardImageSet` is absent (e.g. tests with `MinimalPlugins`). `CardImageSet` is populated at startup from `include_bytes!()` — no `AssetServer`.
+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()`.
 
-Backgrounds are Bevy `Sprite` entities with `Handle<Image>` from `BackgroundImageSet`. `BackgroundImageSet` is populated at startup from `include_bytes!()`.
+Backgrounds are Bevy `Sprite` entities with `Handle<Image>` from `BackgroundImageSet`. `BackgroundImageSet` is populated at startup by `table_plugin::load_background_images` via `AssetServer::load()`.
 
-The font `FiraMono-Medium` is embedded via `include_bytes!()` at startup by `FontPlugin` and exposed as `FontResource` for use by all UI and text systems.
+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.
+
+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.
 
 The `assets/` directory layout:
 
@@ -1004,5 +1011,7 @@ Using `axum::test` and an in-memory SQLite database:
 | `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 |
 | Dropped GPGS backend | Redundant with the self-hosted server; adds JNI complexity for no user-visible benefit on the target platforms | 2026-04-28 |
-| PNG assets embedded via `include_bytes!()` | Using `Image::from_buffer()` in startup systems rather than `AssetServer::load()` keeps the binary self-contained and eliminates runtime file-not-found errors | 2026-04-29 |
+| 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 |
-| FiraMono-Medium font embedded via `include_bytes!()` | Exposed through `FontResource`; avoids runtime font loading errors on headless systems and ensures consistent text rendering across all platforms | 2026-04-29 |
+| 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 |

CLAUDE.md

@@ -1,111 +1,571 @@
-# Solitaire Quest — Claude Code Instructions
+# CLAUDE.md
 
-See @ARCHITECTURE.md for full project design, crate responsibilities, data models, and API reference.
+version: unified-3.0
 
 ---
 
-## Project Layout
+# 0. Role of This File
 
-```text
+This document defines:
-solitaire_core/    # Pure Rust game logic — NO Bevy, NO network, NO I/O
+
-solitaire_sync/    # Shared API types — NO Bevy, serde/uuid/chrono only
+* **Execution rules (what Claude must do)**
-solitaire_data/    # Persistence + SyncProvider trait + server client
+* **System constraints (what Claude must never violate)**
-solitaire_engine/  # Bevy ECS systems, components, plugins
+* **Operational architecture (how code is structured)**
-solitaire_server/  # Axum sync server binary
+
-solitaire_app/     # Thin binary entry point
+For full system design details:
-assets/            # Source assets — embedded at compile time via include_bytes!()
+→ `ARCHITECTURE.md` (authoritative source of truth)
+
+This file overrides all conversational assumptions.
+
+---
+
+# 1. System Architecture (Authoritative Mapping)
+
+## 1.1 Crates
+
+```text id="crate_map"
+solitaire_core/    # PURE logic (no IO, no Bevy, deterministic)
+solitaire_sync/    # Shared API + merge logic
+solitaire_data/    # Persistence + sync client
+solitaire_engine/  # Bevy ECS + UI + gameplay orchestration
+solitaire_server/  # Axum backend (optional sync layer)
+solitaire_app/     # Entry binary
+assets/            # Runtime assets (except audio)
 ```
 
 ---
 
-## Build & Test Commands
+## 1.2 Architecture Source of Truth
 
-```bash
+* Full system design: `ARCHITECTURE.md`
-# Dev run (fast compile via dynamic linking)
+* This file NEVER redefines system design
-cargo run -p solitaire_app --features bevy/dynamic_linking
+* This file ONLY enforces behavior
 
-# Release build
+---
-cargo build --workspace --release
 
-# All tests — MUST pass before any commit
+# 2. Hard Global Constraints (NON-NEGOTIABLE)
+
+These override all other instructions.
+
+## 2.1 Core Determinism
+
+* `solitaire_core` MUST:
+
+  * be deterministic
+  * be side-effect free
+  * never depend on Bevy / IO / async
+
+---
+
+## 2.2 Sync Isolation
+
+* `solitaire_sync`:
+
+  * no Bevy
+  * no IO
+  * no engine dependencies
+* merge logic must be pure functions only
+
+---
+
+## 2.3 Error Policy
+
+* NO `unwrap()`
+* NO `panic!()` in runtime/game logic
+* All state transitions:
+
+```rust id="err_model"
+Result<T, MoveError>
+```
+
+---
+
+## 2.4 Threading Rules
+
+* Sync must run on `AsyncComputeTaskPool`
+* NEVER block Bevy main thread
+
+---
+
+## 2.5 Persistence Rules
+
+* atomic writes only:
+
+  * write `.tmp`
+  * rename atomically
+* no partial state writes allowed
+
+---
+
+## 2.6 Security Rules
+
+* credentials ONLY via `keyring`
+* NEVER store secrets in:
+
+  * files
+  * logs
+  * source code
+
+---
+
+## 2.7 Sync System Rules
+
+* All sync backends implement:
+
+```rust id="sync_trait"
+trait SyncProvider
+```
+
+* `SyncPlugin` MUST be backend-agnostic
+* NEVER match on backend inside ECS systems
+
+---
+
+# 3. Engine Rules (Bevy Layer)
+
+## 3.1 ECS Design
+
+* systems = single responsibility
+* communication = Events only
+* shared state = Resources only
+* per-entity state = Components only
+
+---
+
+## 3.2 Game State Authority
+
+* ONLY `GameStateResource` can mutate game state
+* UI systems MUST NOT directly modify core logic
+
+---
+
+## 3.3 UI-First Constraint (CRITICAL)
+
+Every player action MUST:
+
+* have a visible UI control
+* NOT rely solely on keyboard shortcuts
+
+Keyboard shortcuts are:
+→ optional accelerators only
+
+---
+
+## 3.4 Layout System
+
+* recompute on `WindowResized`
+* no fixed resolution assumptions
+
+---
+
+# 4. Asset System Rules
+
+## 4.1 Runtime Assets (AssetServer)
+
+Loaded via:
+
+* `CardImageSet`
+* `BackgroundImageSet`
+* `FontResource`
+
+Includes:
+
+* cards
+* backgrounds
+* fonts
+
+---
+
+## 4.2 Embedded Assets
+
+Only audio:
+
+```text id="audio_rule"
+include_bytes!()
+```
+
+---
+
+## 4.3 Test Compatibility Rule
+
+All asset loaders MUST accept:
+
+```rust id="asset_fallback"
+Option<Res<AssetServer>>
+```
+
+Must degrade gracefully under `MinimalPlugins`.
+
+---
+
+# 5. Code Standards
+
+## 5.1 Error Handling
+
+* use `thiserror`
+* no `Box<dyn Error>` in libraries
+
+---
+
+## 5.2 Public API Rules
+
+* prefer `Into<T>` over concrete types
+* all public items require doc comments
+
+---
+
+## 5.3 Derive Order
+
+```rust id="derive_order"
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+```
+
+---
+
+## 5.4 Performance Rules
+
+* NO `clone()` in hot paths
+* profile before optimizing
+
+---
+
+## 5.5 SQL Rules
+
+* ONLY `sqlx::query!`
+* NO raw SQL strings
+
+---
+
+# 6. Build & Verification Rules
+
+These are mandatory before ANY commit.
+
+```bash id="build_rules"
 cargo test --workspace
-
-# Lint — MUST pass clean (zero warnings)
 cargo clippy --workspace -- -D warnings
-
-# Run sync server locally
-cargo run -p solitaire_server
-
-# Check a single crate
-cargo test -p solitaire_core
-cargo clippy -p solitaire_core -- -D warnings
 ```
 
 ---
 
-## Hard Rules
+# 7. Git Workflow Rules
 
-- `solitaire_core` and `solitaire_sync` must never gain Bevy or network dependencies.
+## Commit format
-- No `unwrap()` or `panic!()` in game logic. All state transitions return `Result<_, MoveError>`.
+
-- Audio assets are embedded at compile time using `include_bytes!()` in `audio_plugin.rs`. Cards and backgrounds are rendered procedurally (colored `Sprite` entities + text) — no image files are used and no `AssetServer` is needed.
+```text id="commit_fmt"
-- Atomic file writes only: write to `filename.json.tmp`, then `rename()`.
+type(scope): description
-- 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.
+Examples:
-- `cargo clippy --workspace -- -D warnings` must pass clean after every change.
+
-- `cargo test --workspace` must pass after every change.
+* feat(core): add draw-three rules
+* fix(engine): correct drag z-order
+* test(core): undo boundary cases
 
 ---
 
-## Code Style
+## Commit conditions
 
-- Use `thiserror` for error types. Never `Box<dyn Error>` in library crates.
+* tests must pass
-- Prefer `Into<T>` over concrete types in public API function parameters.
+* clippy must be clean
-- All public items must have doc comments (`///`). Private items: comment only when non-obvious.
+
-- Derive order convention: `#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]`
+NEVER commit otherwise
-- Bevy systems: one responsibility per system. Use `Events` for cross-system communication, never shared mutable state.
-- SQL queries: use `sqlx::query!` macros (compile-time checked), not raw string queries.
-- No `clone()` calls in hot paths (game loop systems). Profile before optimising elsewhere.
 
 ---
 
-## Bevy Conventions
+# 8. Change Control (ASK BEFORE DOING)
 
-- One `Plugin` per major feature: `CardPlugin`, `AudioPlugin`, `AchievementPlugin`, `UIPlugin`, `SyncPlugin`.
+Claude must request confirmation before:
-- 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.
+* adding dependencies
-- Layout is recomputed on `WindowResized` — never assume a fixed window size.
+* modifying `solitaire_sync`
+* changing DB schema
+* introducing `unsafe`
+* changing merge strategy
 
 ---
 
-## Git Workflow
+# 9. System Mental Model (IMPORTANT)
 
-- Commit after each passing phase, not after every file change.
+```text id="mental_model"
-- Commit message format: `type(scope): description`
+Core (rules + deterministic logic)
-  - `feat(core): add draw-three mode validation`
+    ↓
-  - `fix(engine): card z-order during drag`
+Engine (Bevy orchestration)
-  - `test(core): undo stack boundary conditions`
+    ↓
-  - `chore(server): add sqlx migration 002`
+Data layer (persistence + sync)
-- Never commit with failing tests or clippy warnings.
+    ↓
-- Never commit secrets, `.env` files, or `*.db` files.
+Server (optional external system)
+```
+
+Core is always the source of truth.
 
 ---
 
-## Ask Before Doing
+# 10. Known Platform Pitfalls
 
-- Adding a new crate dependency (discuss alternatives first).
+Must always be handled explicitly:
-- Changing a type in `solitaire_sync` (breaking change on both client and server).
+
-- Altering the database schema (requires a new sqlx migration).
+* Bevy `Time` uses `f32`
-- Introducing `unsafe` code anywhere.
+* `sqlx::migrate!()` path is crate-relative
-- Changing the merge strategy in `solitaire_sync::merge()`.
+* `dirs::data_dir()` may return `None`
+* Linux may lack keyring backend
 
 ---
 
-## Lessons Learned
+# 11. Forbidden Patterns
 
-> Add entries here when Claude makes a mistake so it isn't repeated.
+* game logic inside Bevy systems
+* duplication across crates
+* blocking async calls in ECS
+* insecure credential storage
+* bypassing core logic layer
 
-- Bevy's `Time` resource uses `f32` seconds; convert to `u64` only when writing to `StatsSnapshot`.
+---
-- `sqlx::migrate!()` macro path is relative to the crate root, not the workspace root.
+
-- `keyring` on Linux requires a running secret service (e.g. GNOME Keyring or KWallet) — handle `Error::NoStorageAccess` gracefully and fall back to prompting the user.
+# 12. Execution Rules for Claude
-- `dirs::data_dir()` returns `None` on some minimal Linux environments — always handle the `None` case explicitly, do not unwrap.
+
+When generating code:
+
+1. respect crate boundaries
+2. minimize diff size
+3. do not expand scope
+4. follow existing patterns
+5. preserve invariants
+
+If unclear:
+→ ask before acting
+
+---
+
+# 13. Relationship to ARCHITECTURE.md
+
+| File            | Role                      |
+| --------------- | ------------------------- |
+| CLAUDE.md       | execution + constraints   |
+| ARCHITECTURE.md | system design truth       |
+| Both combined   | full system understanding |
+
+---
+# 14. Context Injection System (AUTOMATIC SCOPE FILTER)
+
+## 14.1 Purpose
+
+Before generating any response, Claude MUST construct a **minimal relevant context set**.
+
+This prevents:
+
+* architectural drift
+* irrelevant spec loading
+* over-engineering
+* cross-crate confusion
+
+---
+
+## 14.2 Input Classification Step (MANDATORY)
+
+Every request MUST be classified into exactly one task type:
+
+```text id="task_types"
+feature
+bugfix
+refactor
+system_design
+bevy_system
+core_logic
+sync
+optimization
+test
+debug
+```
+
+If uncertain → ask clarification.
+
+---
+
+## 14.3 Context Selection Engine
+
+After classification, Claude MUST include ONLY the relevant sections below.
+
+---
+
+## 14.4 Context Map (CORE RULESET)
+
+### feature
+
+Include:
+
+* §2 Hard Global Constraints
+* §3 Engine Rules
+* ARCHITECTURE.md (crate of target feature only)
+* relevant data models (GameState, SyncPayload if needed)
+
+---
+
+### bugfix
+
+Include:
+
+* §2 Hard Global Constraints
+* §5 Code Standards
+* affected crate boundaries
+* relevant system (engine/core/sync only)
+
+---
+
+### refactor
+
+Include:
+
+* §3 Engine Rules
+* §5 Code Standards
+* §11 Forbidden Patterns
+* target crate boundaries
+
+---
+
+### system_design
+
+Include:
+
+* ARCHITECTURE.md (FULL)
+* §9 Mental Model
+* §1 System Architecture Mapping
+
+---
+
+### core_logic
+
+Include:
+
+* solitaire_core rules only
+* GameState model
+* MoveError model
+* §2.1–2.3 constraints
+
+---
+
+### bevy_system
+
+Include:
+
+* §3 Engine Rules
+* ECS rules (Events/Resources/Components)
+* UI-first constraint
+* relevant plugin system only
+
+---
+
+### sync
+
+Include:
+
+* SyncProvider trait
+* merge strategy rules
+* solitaire_sync models
+* §2.6 Sync Rules
+
+---
+
+### optimization
+
+Include:
+
+* target crate only
+* §5.4 Performance Rules
+* hot path constraints
+
+---
+
+### test
+
+Include:
+
+* §6 Build Rules
+* relevant module
+* expected invariants
+
+---
+
+### debug
+
+Include:
+
+* target file/module only
+* §2.3 Error Policy
+* runtime assumptions relevant to failure
+
+---
+
+## 14.5 Context Compression Rules
+
+Claude MUST obey:
+
+* never include full ARCHITECTURE.md unless system_design
+* max 2 crates per response unless explicitly required
+* prefer function-level context over file-level context
+* exclude unrelated plugins/systems
+
+---
+
+## 14.6 Context Priority Order
+
+When space is limited:
+
+1. Hard Constraints (§2)
+2. Target crate rules
+3. Data models
+4. Only then: architecture snippets
+
+---
+
+## 14.7 “No Context Pollution” Rule
+
+Claude must NOT include:
+
+* unrelated crates
+* unrelated plugins
+* unused data models
+* full architecture dumps
+* speculative systems
+
+---
+
+## 14.8 Self-Check Before Execution
+
+Before writing code, Claude MUST verify:
+
+* [ ] Is only relevant context included?
+* [ ] Is at least one hard constraint present?
+* [ ] Am I touching more than one crate unnecessarily?
+* [ ] Am I duplicating ARCHITECTURE.md content?
+
+If any fail → revise context selection.
+
+---
+
+## 14.9 Injection Output Format (Internal Model)
+
+Claude should behave as if it constructed:
+
+```text id="ctx_format"
+[SELECTED TASK TYPE]
+
+[MINIMAL REQUIRED RULES]
+
+[MINIMAL ARCHITECTURE SLICES]
+
+[RELEVANT MODELS]
+
+[REQUEST]
+```
+
+---
+
+## 14.10 Relationship to ARCHITECTURE.md
+
+* ARCHITECTURE.md = source of truth
+* CLAUDE.md = execution constraints
+* THIS SECTION = filtering layer between them
+
+---
+
+# END CONTEXT INJECTION SYSTEM

CLAUDE_PROMPT_PACK.md

@@ -0,0 +1,497 @@
+# CLAUDE_PROMPT_PACK.md
+
+version: 1.0
+
+---
+
+# 0. GLOBAL INSTRUCTION (prepend to every prompt)
+
+```
+You must follow CLAUDE_SPEC.md strictly.
+
+Rules:
+- Do not expand scope beyond what is defined
+- Do not refactor unrelated code
+- Do not introduce new dependencies
+- Prefer minimal, surgical changes
+- Use existing patterns in the codebase
+- Return minimal diffs or changed functions only
+
+Before writing code:
+1. List relevant constraints from CLAUDE_SPEC.md
+2. Identify risks
+3. Then implement
+```
+
+---
+
+# 1. FEATURE IMPLEMENTATION
+
+```
+# TASK: Feature Implementation
+
+feature: "<name>"
+
+goal:
+"<clear outcome>"
+
+scope:
+crates: []
+systems: []
+files: []
+
+non_goals:
+- ""
+
+constraints:
+- must follow CLAUDE_SPEC.md
+- event-driven architecture required
+- no blocking operations
+- no cross-crate leakage
+
+acceptance_criteria:
+- ""
+- ""
+
+edge_cases:
+- ""
+
+---
+
+## Required Patterns
+
+Use this pattern for systems:
+<PASTE EXISTING SYSTEM SNIPPET HERE>
+
+---
+
+## Output Format
+
+intent:
+plan:
+constraints_used:
+risks:
+
+code_changes:
+(minimal diffs only)
+
+notes:
+```
+
+---
+
+# 2. BUGFIX
+
+```
+# TASK: Bug Fix
+
+bug_description:
+"<what is broken>"
+
+expected_behavior:
+"<correct behavior>"
+
+root_cause_hint (optional):
+""
+
+scope:
+crates: []
+files: []
+
+constraints:
+- minimal fix only
+- no refactors unless required
+- must add regression protection if applicable
+
+---
+
+## Requirements
+
+1. Identify root cause
+2. Fix it minimally
+3. Preserve all invariants
+4. Do not change unrelated logic
+
+---
+
+## Output Format
+
+analysis:
+root_cause:
+fix_strategy:
+
+code_changes:
+(minimal diff)
+
+regression_test (only if high-value):
+
+notes:
+```
+
+---
+
+# 3. REFACTOR
+
+```
+# TASK: Refactor
+
+target:
+"<what is being improved>"
+
+goal:
+"<what improves>"
+
+scope:
+crates: []
+files: []
+
+non_goals:
+- no behavior changes
+- no new features
+
+constraints:
+- must preserve behavior exactly
+- must respect crate boundaries
+- must not duplicate logic
+
+---
+
+## Refactor Type
+
+- [ ] simplify logic
+- [ ] reduce duplication
+- [ ] improve readability
+- [ ] performance (non-invasive)
+
+---
+
+## Output Format
+
+analysis:
+issues_found:
+
+refactor_plan:
+
+code_changes:
+(diff only)
+
+verification:
+- behavior unchanged: yes/no
+- invariants preserved: yes/no
+
+notes:
+```
+
+---
+
+# 4. SYSTEM DESIGN (NEW FEATURE)
+
+```
+# TASK: System Design
+
+feature:
+"<name>"
+
+goal:
+"<what problem it solves>"
+
+constraints:
+- must fit existing architecture
+- must follow plugin + event model
+- must not violate crate boundaries
+
+---
+
+## Required Output
+
+design:
+
+components:
+- plugins:
+- systems:
+- events:
+- resources:
+
+data_flow:
+(step-by-step)
+
+integration_points:
+- where it connects to existing systems
+
+risks:
+- ""
+
+tradeoffs:
+- ""
+
+---
+
+## DO NOT
+
+- write full implementation
+- modify unrelated systems
+```
+
+---
+
+# 5. NEW BEVY SYSTEM
+
+```
+# TASK: Add Bevy System
+
+system_name:
+""
+
+trigger:
+(event or condition)
+
+reads:
+[Resources]
+
+writes:
+[Resources]
+
+emits:
+[Events]
+
+constraints:
+- must be event-driven
+- must not directly mutate unrelated state
+- must be single responsibility
+
+---
+
+## Output Format
+
+system_signature:
+
+implementation:
+(code only)
+
+notes:
+```
+
+---
+
+# 6. CORE LOGIC FUNCTION (solitaire_core)
+
+```
+# TASK: Core Logic Implementation
+
+function:
+"<name>"
+
+goal:
+"<what it does>"
+
+rules:
+- no IO
+- no async
+- no Bevy
+- deterministic
+
+invariants:
+- ""
+- ""
+
+errors:
+- ""
+
+---
+
+## Output Format
+
+constraints_checked:
+
+implementation:
+(code only)
+
+edge_case_handling:
+
+notes:
+```
+
+---
+
+# 7. SYNC / MERGE LOGIC
+
+```
+# TASK: Sync Logic
+
+goal:
+"<what is being merged or synced>"
+
+constraints:
+- must be deterministic
+- must be idempotent
+- must be lossless
+- must not delete data
+
+rules:
+- counters → max
+- times → min
+- collections → union
+
+---
+
+## Output Format
+
+analysis:
+
+merge_logic:
+
+code_changes:
+
+invariants_verified:
+- deterministic
+- idempotent
+- lossless
+
+notes:
+```
+
+---
+
+# 8. PERFORMANCE OPTIMIZATION
+
+```
+# TASK: Optimization
+
+target:
+"<what is slow>"
+
+constraints:CLAUDE_WORKFLOW.md
+- no behavior change
+- no architecture change
+- minimal code changes
+
+---
+
+## Output Format
+
+analysis:
+bottleneck:
+
+optimization_strategy:
+
+code_changes:
+
+impact_estimate:
+
+notes:
+```
+
+---
+
+# 9. TEST GENERATION (STRICT MODE)
+
+```
+# TASK: Test Generation
+
+target:
+"<function/system>"
+
+reason:
+- bugfix | complex logic | invariant protection
+
+constraints:
+- no redundant tests
+- must test real behavior
+- must fail if logic breaks
+
+---
+
+## Output Format
+
+test_cases:
+- ""
+
+test_code:
+
+notes:
+```
+
+---
+
+# 10. DEBUGGING / INVESTIGATION
+
+```
+# TASK: Debug
+
+problem:
+"<symptom>"
+
+context:
+"<relevant code or system>"
+
+---
+
+## Required Steps
+
+1. List possible causes
+2. Narrow down most likely
+3. Suggest verification steps
+4. Provide minimal fix
+
+---
+
+## Output Format
+
+hypotheses:
+
+most_likely:
+
+verification_steps:
+
+fix:
+
+notes:
+```
+
+---
+
+# 11. HARD CONSTRAINT OVERRIDE (RARE)
+
+```
+# TASK: Exception Handling
+
+reason:
+"<why constraints must be bent>"
+
+requested_exception:
+"<rule being broken>"
+
+justification:
+"<why unavoidable>"
+
+---
+
+## Output Format
+
+analysis:
+
+alternatives_considered:
+
+final_decision:
+
+risk:
+```
+
+---
+
+# 12. STOP CONDITIONS (always append)
+
+```
+Stop when:
+- acceptance criteria are met
+- code is minimal and correct
+
+Do NOT:
+- expand scope
+- refactor unrelated code
+- optimize prematurely
+```
+
+---
+
+# END

CLAUDE_SPEC.md

@@ -0,0 +1,292 @@
+# CLAUDE_SPEC.md
+
+version: 1.0
+
+---
+
+## 0. Global Rules
+
+(Core determinism, panic policy, and event-driven engine constraints live in CLAUDE.md §2.1, §2.3, §3.1. Listed here only when they add information CLAUDE.md doesn't carry.)
+
+rules:
+
+* id: single_source_of_truth
+  description: "GameStateResource is the only mutable game state in runtime"
+
+* id: sync_is_additive
+  description: "Remote data must never destructively overwrite local data"
+
+---
+
+## 1. Crate Graph
+
+crates:
+solitaire_core:
+depends_on: [rand, serde, chrono]
+forbidden_deps: [bevy, reqwest, tokio, std::fs]
+
+solitaire_sync:
+depends_on: [serde, serde_json, uuid, chrono]
+role: "shared_types"
+
+solitaire_data:
+depends_on: [solitaire_core, solitaire_sync, reqwest, tokio, keyring]
+role: "persistence_and_sync"
+
+solitaire_engine:
+depends_on: [bevy, kira, solitaire_core, solitaire_data]
+role: "runtime_engine"
+
+solitaire_server:
+depends_on: [solitaire_sync, axum, sqlx, jsonwebtoken]
+role: "backend"
+
+solitaire_app:
+depends_on: [solitaire_engine]
+role: "entrypoint"
+
+---
+
+## 2. Data Ownership
+
+ownership:
+GameState:
+owner: solitaire_core
+mutable_in: solitaire_engine
+access_pattern: "via GameStateResource only"
+
+StatsSnapshot:
+owner: solitaire_data
+
+PlayerProgress:
+owner: solitaire_data
+
+AchievementRecord:
+owner: solitaire_data
+
+SyncPayload:
+owner: solitaire_sync
+
+---
+
+## 3. State Transitions
+
+state_machine:
+GameState:
+transitions:
+- action: move_cards
+returns: Result<GameState, MoveError>
+
+```
+  - action: draw
+    returns: Result<GameState, MoveError>
+
+  - action: undo
+    returns: Result<GameState, MoveError>
+
+invariants:
+  - "52 cards always exist"
+  - "no duplicate card IDs"
+  - "all cards belong to exactly one pile"
+```
+
+---
+
+## 4. Event System
+
+events:
+
+input:
+- MoveRequestEvent
+- DrawRequestEvent
+- UndoRequestEvent
+- NewGameRequestEvent
+
+state:
+- StateChangedEvent
+- GameWonEvent
+
+meta:
+- AchievementUnlockedEvent
+- SyncCompleteEvent
+
+rules:
+
+* "Input events trigger core logic"
+* "Core logic emits state events"
+* "UI reacts to state events only"
+
+---
+
+## 5. Sync Contract
+
+sync:
+
+provider_trait:
+methods:
+- pull() -> SyncPayload
+- push(payload) -> SyncResponse
+
+guarantees:
+- "non-blocking during gameplay"
+- "blocking allowed on exit only"
+
+merge:
+rules:
+counters: "max"
+best_times: "min"
+collections: "union"
+achievements: "never removed"
+
+```
+properties:
+  - deterministic
+  - idempotent
+  - lossless
+```
+
+---
+
+## 6. Persistence
+
+storage:
+
+format: json
+
+files:
+- stats.json
+- progress.json
+- achievements.json
+- settings.json
+- game_state.json
+
+guarantees:
+- atomic_write: true
+- crash_safe: true
+
+---
+
+## 7. Engine Rules
+
+engine:
+
+mutation_rules:
+- "Only GameLogicSystem mutates GameState"
+- "UI systems are read-only"
+
+threading:
+- "sync runs on AsyncComputeTaskPool"
+- "main thread must never block"
+
+plugins:
+pattern: "feature_isolation"
+communication: "events"
+
+---
+
+## 8. Server Contract
+
+server:
+
+auth:
+method: jwt
+access_expiry: 24h
+refresh_expiry: 30d
+
+endpoints:
+- POST /api/auth/register
+- POST /api/auth/login
+- GET /api/sync/pull
+- POST /api/sync/push
+
+limits:
+payload_max: 1MB
+rate_limit: "10 req/min auth routes"
+
+---
+
+## 9. Achievement System
+
+achievements:
+
+definition_location: solitaire_core
+state_location: solitaire_data
+
+types:
+- condition_based
+- event_driven
+
+rule:
+- "achievements cannot be revoked"
+
+---
+
+## 10. Testing Rules
+
+testing:
+
+philosophy:
+- "test real failures"
+- "avoid redundant tests"
+
+required_coverage:
+solitaire_core:
+- move_validation
+- undo_integrity
+- win_detection
+
+```
+solitaire_sync:
+  - merge_correctness
+  - idempotency
+```
+
+---
+
+## 11. Prohibited Patterns
+
+(See CLAUDE.md §11 for the canonical forbidden-patterns list.)
+
+---
+
+## 12. Extension Points
+
+extensibility:
+
+sync_backends:
+pattern: "implement SyncProvider"
+
+game_modes:
+location: solitaire_core::GameMode
+
+plugins:
+rule: "new feature = new plugin"
+
+---
+
+## 13. Validation Checklist (for Claude)
+
+validation:
+
+* check: "crate dependency rules respected"
+* check: "no panics in core"
+* check: "events used for cross-system communication"
+* check: "GameState mutations centralized"
+* check: "merge function properties preserved"
+* check: "no blocking operations in main loop"
+
+---
+
+## 14. Mental Model
+
+model:
+
+layers:
+- core
+- engine
+- data
+- server
+
+flow:
+- input -> engine -> core -> engine -> ui
+- data <-> sync <-> server

CLAUDE_WORKFLOW.md

@@ -0,0 +1,335 @@
+# CLAUDE_WORKFLOW.md
+
+version: 1.0
+
+---
+
+## 0. Overview
+
+This workflow defines a **two-agent system**:
+
+* **Builder Agent** → writes and modifies code
+* **Guardian Agent** → enforces architecture + rejects invalid changes
+
+No code is considered valid unless it passes Guardian validation.
+
+---
+
+## 1. Agent Roles
+
+### 1.1 Builder Agent
+
+role: "code_generation"
+
+responsibilities:
+
+* implement features
+* refactor code
+* generate tests (only when justified)
+* follow CLAUDE_SPEC.md
+
+constraints:
+
+* cannot bypass validation
+* must declare intent before writing code
+
+output_contract:
+must_produce:
+- change_summary
+- files_modified
+- reasoning (short)
+- code_diff
+
+---
+
+### 1.2 Guardian Agent
+
+role: "architecture_enforcement"
+
+responsibilities:
+
+* validate against CLAUDE_SPEC.md
+* detect violations
+* reject or approve changes
+* suggest minimal fixes (not full rewrites)
+
+constraints:
+
+* no feature implementation
+* no large rewrites
+* must be deterministic
+
+output_contract:
+must_produce:
+- status: APPROVED | REJECTED
+- violations[]
+- required_fixes[]
+- optional_improvements[]
+
+---
+
+## 2. Workflow Pipeline
+
+```text
+User Request
+    ↓
+Builder Agent (proposal + code)
+    ↓
+Guardian Agent (validation)
+    ↓
+IF approved → commit
+IF rejected → feedback → Builder retry
+```
+
+---
+
+## 3. Builder Protocol
+
+### Step 1 — Intent Declaration
+
+Builder MUST start with:
+
+```yaml
+intent:
+  feature: "<name>"
+  crates_touched: []
+  systems_affected: []
+  risk_level: low|medium|high
+```
+
+---
+
+### Step 2 — Plan
+
+```yaml
+plan:
+  - step: "..."
+  - step: "..."
+```
+
+---
+
+### Step 3 — Implementation
+
+* Only modify declared crates
+* Follow ownership rules
+* Use events for cross-system communication
+
+---
+
+### Step 4 — Output
+
+```yaml
+change_summary: "..."
+
+files_modified:
+  - path: ...
+    change: "..."
+
+violations_self_check:
+  - none | list
+
+notes: "short reasoning"
+```
+
+---
+
+## 4. Guardian Protocol
+
+### Step 1 — Spec Validation
+
+Check against:
+
+* crate boundaries
+* mutation rules
+* event system usage
+* sync guarantees
+* forbidden patterns
+
+---
+
+### Step 2 — Invariant Validation
+
+Must verify:
+
+* GameState invariants preserved
+* no new panic paths
+* no blocking calls in engine
+* merge properties unchanged
+
+---
+
+### Step 3 — Output Decision
+
+#### APPROVED
+
+```yaml
+status: APPROVED
+
+notes:
+  - "no violations"
+```
+
+---
+
+#### REJECTED
+
+```yaml
+status: REJECTED
+
+violations:
+  - id: core_purity_violation
+    file: "solitaire_core/src/..."
+    reason: "uses std::fs"
+
+required_fixes:
+  - "move IO to solitaire_data"
+
+optional_improvements:
+  - "simplify event naming"
+```
+
+---
+
+## 5. Enforcement Rules
+
+### Hard Fail (automatic rejection)
+
+* core crate uses IO / Bevy / network
+* GameState mutated outside GameLogicSystem
+* blocking async on main thread
+* duplicate logic across crates
+* merge function altered incorrectly
+
+---
+
+### Soft Fail (allowed but flagged)
+
+* unnecessary complexity
+* redundant tests
+* minor architectural drift
+
+---
+
+## 6. Iteration Loop
+
+Max attempts per task: **3**
+
+```text
+Attempt 1 → Reject → Fix
+Attempt 2 → Reject → Fix
+Attempt 3 → Final decision
+```
+
+If still failing:
+→ escalate to user
+
+---
+
+## 7. Diff Strategy
+
+Builder MUST produce:
+
+* minimal diffs
+* no unrelated refactors
+* no formatting-only changes
+
+---
+
+## 8. Test Strategy Integration
+
+Builder rules:
+
+* only add tests if:
+
+  * fixing a bug
+  * protecting complex logic
+  * validating invariants
+
+Guardian rejects:
+
+* redundant tests
+* no-op tests
+
+---
+
+## 9. Optional Extensions
+
+### 9.1 Third Agent (Optimizer)
+
+role: performance + cleanup
+
+runs AFTER approval:
+
+* reduce allocations
+* simplify logic
+* improve ECS scheduling
+
+---
+
+### 9.2 CI Integration
+
+Pipeline:
+
+```text
+Builder → Guardian → cargo check → clippy → tests
+```
+
+Guardian runs BEFORE compilation to catch structural issues early.
+
+---
+
+## 10. Example Interaction
+
+### Builder
+
+```yaml
+intent:
+  feature: "undo stack limit fix"
+  crates_touched: [solitaire_core]
+  risk_level: low
+```
+
+```yaml
+change_summary: "limit undo stack to 64 entries"
+
+files_modified:
+  - solitaire_core/src/game_state.rs
+
+notes: "prevents unbounded memory growth"
+```
+
+---
+
+### Guardian
+
+```yaml
+status: APPROVED
+
+notes:
+  - "respects core constraints"
+  - "no invariant violations"
+```
+
+---
+
+## 11. Mental Model
+
+* Builder = **creative**
+* Guardian = **strict**
+
+Builder explores
+Guardian enforces
+
+Neither replaces the other.
+
+---
+
+## 12. Success Criteria
+
+System is working if:
+
+* architectural violations go to ~0
+* code stays consistent across features
+* refactors become safe
+* complexity grows sub-linearly

CREDITS.md

@@ -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.

Cargo.toml

@@ -7,6 +7,7 @@ members = [
     "solitaire_server",
     "solitaire_app",
     "solitaire_assetgen",
+    "solitaire_wasm",
 ]
 resolver = "2"
 
@@ -29,15 +30,91 @@ dirs        = "6"
 keyring     = "4"
 keyring-core = "1"
 reqwest     = { version = "0.13", features = ["json", "rustls", "rustls-native-certs"], default-features = false }
+arboard     = { version = "3", default-features = false }
 
 solitaire_core   = { path = "solitaire_core" }
 solitaire_sync   = { path = "solitaire_sync" }
 solitaire_data   = { path = "solitaire_data" }
 solitaire_engine = { path = "solitaire_engine" }
 
-bevy = "0.18"
+# Bevy with `default-features = false` to avoid the unused
+# `bevy_audio → rodio + symphonia + cpal 0.15 + alsa 0.9` chain.
+# Audio is handled directly by `kira` in `audio_plugin.rs`, so the
+# `bevy_audio` feature is intentionally omitted. The features below
+# enumerate every leaf of the standard `2d` + `ui` meta-features that
+# we actually use; new features should only be added with a
+# corresponding use site.
+bevy = { version = "0.18", default-features = false, features = [
+    # default_app
+    "async_executor",
+    "bevy_asset",
+    "bevy_input_focus",
+    "bevy_log",
+    "bevy_state",
+    "bevy_window",
+    "custom_cursor",
+    "reflect_auto_register",
+    # default_platform (desktop subset)
+    "std",
+    "bevy_winit",
+    "default_font",
+    "multi_threaded",
+    # winit prefers Wayland when WAYLAND_DISPLAY is set on the
+    # session and falls through to X11 otherwise. Without `wayland`,
+    # winit-on-Wayland-session falls back to XWayland which renders
+    # the game in an X11 frame inside the Wayland compositor.
+    "wayland",
+    "x11",
+    # Android: NativeActivity glue. The feature is target-gated inside
+    # bevy_internal — desktop builds compile it out, so leaving it on
+    # the always-on list is harmless on Linux/macOS/Windows. Pairs with
+    # cargo-apk's NativeActivity wrapper (cargo-apk 0.10+ uses this by
+    # default). Switch to `android-game-activity` later if we want
+    # AndroidX GameActivity for Google Play Games integration.
+    "android-native-activity",
+    # common_api
+    "bevy_color",
+    "bevy_image",
+    "bevy_mesh",
+    "bevy_shader",
+    "bevy_text",
+    "png",
+    # 2d rendering
+    "bevy_camera",
+    "bevy_render",
+    "bevy_core_pipeline",
+    "bevy_sprite",
+    "bevy_sprite_render",
+    # UI rendering
+    "bevy_ui",
+    "bevy_ui_render",
+] }
 kira = "0.12"
 
+# SVG rasterisation pipeline for the runtime card-theme system.
+# 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       = { version = "10", default-features = false, features = ["rust_crypto"] }

README.md

@@ -1,17 +1,35 @@
 # 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.
+A cross-platform Klondike Solitaire game written in Rust, with a card-theme
+system, full progression (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
+- **Klondike Solitaire** — Draw One and Draw Three modes; foundations are
+  unlocked (any Ace lands in any empty slot, the slot then claims that suit)
+- **Card themes** — bundled hayeah/playing-cards-assets default plus
+  user-installable themes (drop a directory under the data dir or import a
+  zip from Settings → Cosmetic)
+- **Modern HUD** — reserved top band keeps cards from crowding the score
+  readout; the action bar auto-fades when the cursor leaves it so it can't
+  compete with the play surface
+- **Drag feel** — every legal drop target is highlighted in green during
+  drag; cards cast a soft drop shadow that lifts when picked up; the stock
+  pile shows a remaining-count chip so you can see how close you are to a
+  recycle
+- **Keyboard navigation** — Tab cycles focus through buttons, arrow keys
+  move within picker rows, Enter activates; works across every modal and
+  the HUD action bar
 - **Progression** — XP, levels, unlockable card backs and backgrounds
-- **18 Achievements** — including secret ones
+- **19 Achievements** — including secret ones
-- **Daily Challenge** — server-seeded so every player worldwide gets the same deal
+- **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
+- **Color-blind mode** — blue tint on red-suit cards alongside the suit
+  glyph
 
 ## Building
 
@@ -32,42 +50,73 @@ cargo build -p solitaire_app --release
 
 ## Controls
 
+Every action also has a visible UI button — keyboard shortcuts are optional
+accelerators.
+
 | Key | Action |
 |---|---|
 | Left click / drag | Move cards |
+| Double click | Auto-move card to its best legal destination |
 | Right click | Highlight legal moves for a card |
 | Space / D | Draw from stock |
-| Z / Ctrl+Z | Undo |
+| U | Undo |
+| H | Hint (highlight a legal move) |
 | N | New game |
-| S | Stats overlay |
+| Z | Zen mode |
-| A | Achievements overlay |
+| G | Forfeit (during pause) |
-| P | Profile overlay |
+| Tab / Shift+Tab | Cycle keyboard focus |
-| O | Settings |
+| Enter | Activate focused button / auto-complete (when badge is lit) |
-| L | Leaderboard |
+| Esc | Pause / dismiss modal |
-| H | Help / controls |
+| F1 | Help / controls |
-| Enter | Auto-complete (when badge is lit) |
+| F11 | Toggle fullscreen |
-| Escape | Pause / clear selection |
+| S / A / P / O / L / M | Stats / Achievements / Profile / Settings / Leaderboard / Menu |
-| Arrow keys | Navigate card selection |
+
+## Card themes
+
+The default theme ships embedded in the binary, so the game runs
+self-contained with no external assets. To install another theme, drop a
+directory containing a `theme.ron` manifest plus 53 SVG files (52 faces +
+1 back) under the platform data dir's `themes/` folder, or import a zip
+from **Settings → Cosmetic**. The picker chip lights up the moment a new
+theme is registered. Themes are SVG-based, so they rasterise cleanly at
+whatever resolution the window happens to be.
 
 ## Sync Server (optional)
 
-To sync stats across machines, run the self-hosted server. See [README_SERVER.md](README_SERVER.md) for setup instructions.
+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.
+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
+# All tests (982 passing as of v0.11.0)
 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
+cargo clippy --workspace --all-targets -- -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.
+
+## Changelog
+
+See [CHANGELOG.md](CHANGELOG.md).
+
 ## License
 
 MIT — see [LICENSE](LICENSE).

SESSION_HANDOFF.md

@@ -0,0 +1,282 @@
+# Solitaire Quest — Session Handoff
+
+**Last updated:** 2026-05-07 — v0.20.0 cut. Two through-lines closed
+in this cycle: a full **Terminal visual-identity port** (token system
+in `ui_theme` plus downstream chrome migrations across modal scaffold,
+gameplay-feedback, toasts, and the table / card / splash surfaces)
+and the **Android persistence shim** that closes the
+`dirs::data_dir() = None` pitfall flagged in CLAUDE.md §10. The
+Android *build* target landed earlier in the cycle (`fb8b2ac`); this
+session paid down the persistence half so a real APK can survive a
+cold start. The 24 Stitch-rendered mockups are now in-tree under
+`docs/ui-mockups/`; future plugin work diffs against the matching
+mockup before touching pixels.
+
+## Status at pause
+
+- **HEAD on origin:** the v0.20.0 docs commit (the one that lands
+  this file + CHANGELOG cut). Tag not yet pushed; cut whenever
+  feels right.
+- **Working tree:** clean apart from the still-untracked `artwork/`
+  directory (intentional — the card PNGs there are mid-flight for
+  the Terminal aesthetic and committing now would freeze a
+  transitional state).
+- **Build:** `cargo clippy --workspace --all-targets -- -D warnings`
+  clean.
+- **Tests:** **1176 passing / 0 failing** across the workspace.
+  Six new tests this cycle: four `ui_theme` invariant guards
+  (type / spacing / z-index scales + `scaled_duration`), one
+  toast-variant-border-mapping pair, and four palette-tracking
+  guards on `MARKER_VALID` / `HINT_PILE_HIGHLIGHT_COLOUR` /
+  `RIGHT_CLICK_HIGHLIGHT_COLOUR` / toast-border distinctness. No
+  known flakes.
+- **Tags on origin:** `v0.9.0` through `v0.19.0`. v0.20.0 not yet
+  tagged.
+
+## What shipped in v0.20.0
+
+### Terminal visual-identity port
+
+Top-down stack — every commit downstream of the token system
+reads from it, so swapping the palette is now a one-file edit:
+
+- **`ui_theme` token system** (`0d477ac`). base16-eighties
+  palette, 5-rung type scale, 7-rung 4-multiple spacing scale,
+  3-step radius, 14-rung z-index hierarchy, full motion budget,
+  4 invariant-pinning unit tests. Card-shadow alphas pinned to 0
+  (Terminal achieves depth via 1px borders + tonal layering).
+- **Modal scaffold already on tokens** — `ui_modal` was ported
+  in the same commit's wake; three stale "loud yellow" /
+  "magenta secondary" doc comments fixed.
+- **Gameplay feedback → semantic state tokens** (`ceec4fc`).
+  Selection / valid-drop tints route through `ACCENT_PRIMARY` /
+  `STATE_WARNING` / `STATE_SUCCESS`.
+- **Toasts** (`a137607`). New `ToastVariant` enum
+  (Info / Warning / Error / Celebration); opaque `BG_ELEVATED`
+  + 1px accent border + bottom-anchor. All ten call sites pass
+  their semantic variant.
+- **`table_plugin` chrome** (`651f406`).
+  `PILE_MARKER_DEFAULT_COLOUR` promoted; `cursor_plugin` imports
+  it, replacing a "kept in sync" doc comment with a compile-
+  enforced invariant. `HINT_PILE_HIGHLIGHT_COLOUR` →
+  `STATE_WARNING`.
+- **`card_plugin` chrome** (`d752870`). Drag-elevation shadow
+  routes through `CARD_SHADOW_*` tokens. `RIGHT_CLICK_HIGHLIGHT_COLOUR`
+  → `STATE_SUCCESS`. Stock recycle "↺" text → `TEXT_PRIMARY @ 0.7α`.
+  Card-face / suit / card-back palette intentionally NOT migrated
+  (artwork dependency — see open-list item below).
+- **Splash cursor** (`cdcadda`). The signature `▌` cyan glyph
+  (96 px) added above the wordmark, matching the spec.
+- **Hint-source / dest pairing** (`9891ae4`). `input_plugin`'s
+  source-card tint now matches the destination pile's
+  `STATE_WARNING`.
+- **Design system + 24-mockup library** (`fa7f98a`).
+  `docs/ui-mockups/design-system.md` + 24 Stitch mockups (HTML +
+  PNG) covering every screen plus 9 missing-plugin surfaces.
+- **`card_shadow_params` test aligned** (`1d1543e`). Drag-vs-
+  idle shadow assertion loosened to `>=` to accept the Terminal
+  "no shadow" intent without losing the regression-guard.
+
+### Android persistence
+
+- **`solitaire_data::data_dir` shim** (`4b51e50`). New
+  `solitaire_data::platform::data_dir()` falls through to
+  `dirs::data_dir()` on desktop and returns the per-app sandbox
+  at `/data/data/com.solitairequest.app/files` on Android — no
+  JNI needed (package id pinned in `[package.metadata.android]`).
+  Six `solitaire_data` callsites + `solitaire_engine/assets/user_dir.rs`
+  migrated. Settings, stats, achievements, replays, game-state,
+  time-attack sessions, and user themes now persist on Android.
+
+### Inherited from earlier in the cycle (pre-session)
+
+- Android build target + APK (`fb8b2ac`), runbook (`59424a3`),
+  F3 FPS overlay (`690e1d2`), Smart Window Size opt-out
+  (`e1b8766`), Shareable badge (`9b065e5`), Help cheat-sheet
+  M/P/Enter rows (`35516d3`), `pull_failure_sets_error_status`
+  flake fix (`67c150b`).
+
+## Open punch list
+
+### Phase Android (build + persistence shipped; runtime gaps remain)
+
+- **APK launch verification on AVD / device.** `adb install` then
+  `adb logcat` against the `bevy_test` AVD or an x86_64 device.
+  The build works and persistence is wired, but no end-to-end
+  device run has been logged. Shakes out runtime bugs the build +
+  unit tests can't catch.
+- **JNI ClipboardManager bridge.** Replaces the Android stub for
+  the Stats "Copy share link" toast. `arboard` doesn't ship an
+  Android backend; small custom JNI call.
+- **Android Keystore for credentials.** `keyring` is target-gated
+  to a stub returning `KeychainUnavailable`; replace with Android
+  Keystore via JNI when sync auth ships on mobile.
+- **Google Play Games (gpgs) integration.** Listed as a
+  Phase-Android target since Phase 1; now unblocked by the build
+  target.
+- **Cosmetic `cargo apk build --lib` workaround.** Post-sign
+  panic doesn't affect the APK on disk but produces noisy stderr.
+  Either upstream a cargo-apk fix or document `--lib` as
+  canonical in the runbook.
+
+### Visual-identity follow-ups (opened by v0.20.0's port)
+
+- **Card-face / suit / card-back artwork regeneration.** The
+  Terminal spec calls for dark `#1a1a1a` cards with light suit
+  pips (pink for hearts/diamonds, foreground gray for spades/
+  clubs); the runtime path still renders the legacy white-card
+  PNG artwork. The fallback constants in `card_plugin`
+  (`CARD_FACE_COLOUR`, `RED_SUIT_COLOUR`, `BLACK_SUIT_COLOUR`,
+  `CARD_FACE_COLOUR_RED_CBM`, `card_back_colour` palette) are
+  intentionally unmigrated and should swap in lockstep with the
+  artwork. Largest visible payoff remaining in the visual-
+  identity arc.
+- **Splash boot-loader richness.** The mockup
+  (`docs/ui-mockups/splash-mobile.html`) calls for a scanline
+  overlay, ✓ lime check log lines, pulsing cursor, ROOT@SOLITAIRE
+  prompt, and a loading bar — none of which v0.20.0's
+  cursor-glyph-only port pulled in. Aesthetic feature, its own
+  commit.
+- **Replay-overlay redesign.** The mockup
+  (`docs/ui-mockups/replay-overlay-mobile.html`) envisions a
+  much richer surface (terminal `▌replay.tsx` header, move log
+  scroll, MOVE 47/87 chip, WIN MOVE callout, status bar) versus
+  the current top banner. Aesthetic feature.
+- **Toast Warning / Error variants.** The new `ToastVariant`
+  enum has slots for `Warning` (gold) and `Error` (pink) but no
+  in-engine event uses them yet (the four current toast events
+  all map to Info or Celebration). Wire when a warning- or
+  error-flavoured toast event materialises.
+
+### Carried forward from v0.19.0
+
+- **App icon round.** `Window::icon` not yet wired; no
+  `.icns` / `.ico` / Linux hicolor PNG hierarchy. The 11-size
+  icon export the v0.19 handoff referenced is *not* currently
+  in `artwork/` (current `artwork/` holds the reverted Rusty
+  Pixel card PNGs and is intentionally untracked); icon-export
+  needs to be re-run before this item can be picked up.
+  Half-day task once the PNGs are back in place. No cert
+  dependency.
+
+### Other small candidates
+
+- **Prev/Next selector chips spawn site.** v0.19.0's `9b065e5`
+  noted Prev/Next markers exist in `stats_plugin` but no spawn
+  site renders them today — the Shareable badge therefore lands
+  on the single-replay caption. If/when Prev/Next is plumbed,
+  the badge will need to follow.
+- **Toast queue / immediate unification.** The two toast paths
+  (`spawn_queued_toast` for `InfoToastEvent` queue; `spawn_toast`
+  for fire-and-forget) now share visual treatment but remain
+  separate functions because they serve different temporal
+  needs (sequential vs. parallel). If overlap becomes a UX
+  issue, merge into one queue with priority lanes.
+
+### Process notes
+
+- **Token-port pattern.** v0.20.0's chrome-migration commits
+  set a reusable shape for "centralized design system applied
+  across N plugins":
+  1. Constants module (`ui_theme.rs`) is the source of truth.
+  2. Const sites that can't call `Alpha::with_alpha` (not yet
+     `const` on stable) use a literal RGB matching the token,
+     with a unit test pinning the RGB to the token (e.g.
+     `MARKER_VALID`, `HINT_PILE_HIGHLIGHT_COLOUR`,
+     `RIGHT_CLICK_HIGHLIGHT_COLOUR`).
+  3. Cross-plugin duplication (e.g. `MARKER_DEFAULT` ↔
+     `PILE_MARKER_DEFAULT_COLOUR`) collapses to a single
+     promoted const re-exported from one plugin and imported
+     by the other — replaces "kept in sync" doc comments with a
+     compile-time invariant.
+  4. Domain colours (suit pips, card faces, lerp helpers) stay
+     as literals with a comment naming the rationale; only UI
+     chrome routes through tokens.
+- **Audit before migrating wide.** Before touching any plugin,
+  grep for the literal pattern (`Color::srgb\(|Color::srgba\(|
+  Color::WHITE|Color::BLACK`) and classify each hit as domain
+  vs. chrome. Most plugins after the modal scaffold port turned
+  out to be 100 % token-correct already; the audit prevents
+  wasted churn.
+
+### Canonical remote
+
+`github.com/funman300/Rusty_Solitaire` is the canonical repo.
+Always push there.
+
+### Design direction (now Terminal — base16-eighties)
+
+- **Tone:** retro-terminal / synthwave — flat depth (no box-shadows),
+  monospaced-forward typography (JetBrains Mono / FiraMono), tight
+  16 px edge margins, 8 px card radius.
+- **Palette:** near-black surface ramp (`#151515` / `#202020` / `#2a2a2a`
+  / `#353535`), cyan primary CTA (`#6fc2ef`), lime success
+  (`#acc267`), gold warning (`#ddb26f`), pink error / suit-red
+  (`#fb9fb1`), lavender celebration (`#e1a3ee`), teal info
+  (`#12cfc0`).
+- **Two-color suits.** Red = `#fb9fb1`, black = `#d0d0d0`. Outlined
+  glyphs for diamonds & clubs are *always on*; the Settings
+  "color-blind mode" toggle only swaps red → cyan.
+
+(Was: Midnight Purple base + Balatro yellow primary + warm magenta.
+Replaced this cycle.)
+
+## Resume prompt
+
+```
+You are a senior Rust + Bevy developer working on Solitaire Quest.
+Working directory: <Rusty_Solitaire clone path on this machine>.
+Branch: master. v0.20.0 just cut on 2026-05-07; CHANGELOG's new
+[Unreleased] section is empty pending the next cycle's threads.
+
+State: HEAD on the v0.20.0 docs commit. Tag not pushed yet — last
+pushed tag is v0.19.0. Working tree clean apart from the
+intentionally-untracked `artwork/`.
+
+READ FIRST (in order, before doing anything):
+  1. SESSION_HANDOFF.md  — this file
+  2. CHANGELOG.md        — [0.20.0] section is the most recent cut
+  3. CLAUDE.md           — unified-3.0 rule set
+  4. CLAUDE_SPEC.md      — formal architecture spec
+  5. ARCHITECTURE.md     — crate responsibilities + data flow
+  6. docs/ui-mockups/    — design system + 24-mockup library
+                           (Terminal aesthetic — landed in fa7f98a)
+  7. docs/android/*      — Android setup + build runbook
+  8. ~/.claude/projects/<this-project>/memory/MEMORY.md
+                         — saved feedback / project context
+                           (machine-local; may be missing on a
+                           fresh machine)
+
+DECISION TO ASK THE PLAYER FIRST:
+  A. Push v0.20.0 tag — `git tag v0.20.0 && git push --tags`. If
+     the player wants the cut formalised before any new work.
+  B. APK launch verification — `adb install` + `adb logcat` on
+     bevy_test AVD or an x86_64 device. Now that persistence is
+     wired (4b51e50), shake out remaining runtime bugs.
+  C. Card-face artwork regeneration — generate Terminal-aesthetic
+     card PNGs (dark face, light suit pips), then migrate
+     CARD_FACE_COLOUR / RED_SUIT_COLOUR / BLACK_SUIT_COLOUR /
+     CARD_FACE_COLOUR_RED_CBM in lockstep. Largest visible
+     payoff remaining in the visual-identity arc.
+  D. Splash boot-loader richness — port the scanline overlay,
+     ✓ check log, pulsing cursor, ROOT@SOLITAIRE prompt, and
+     loading bar from docs/ui-mockups/splash-mobile.html. Pure
+     polish; no behavioural change.
+  E. App icon round — re-run artwork/Icon Export.html (the
+     export PNGs are not currently in `artwork/`), then wire
+     Window::icon + generate .icns / .ico. Half-day task. No
+     cert dependency.
+  F. JNI ClipboardManager / Keystore bridge — replaces the
+     Android stubs for Stats clipboard share + sync auth.
+
+WORKFLOW NOTES:
+  - Use the system git config (already correct).
+  - When attributing playtester feedback in commits/docs, use
+    "Quat" not "Rhys" (saved feedback memory).
+  - Sub-agents stage + verify only; orchestrator commits.
+  - Every commit must pass build / clippy / test before pushing.
+  - Push to GitHub (origin) — gh auth setup-git wired on
+    primary dev box; verify on laptop before first push.
+
+OPEN AT THE START: ask which of A–F. Don't pick unilaterally.
+```