feat(workspace): initialize all seven crates with stubs and blank Bevy window

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

CLAUDE.md

@@ -0,0 +1,113 @@
+# Solitaire Quest — Claude Code Instructions
+
+See @ARCHITECTURE.md for full project design, crate responsibilities, data models, and API reference.
+
+---
+
+## Project Layout
+
+```
+solitaire_core/    # Pure Rust game logic — NO Bevy, NO network, NO I/O
+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/            # Loaded at runtime via Bevy AssetServer only
+```
+
+---
+
+## Build & Test Commands
+
+```bash
+# Dev run (fast compile via dynamic linking)
+cargo run -p solitaire_app --features bevy/dynamic_linking
+
+# Release build
+cargo build --workspace --release
+
+# All tests — MUST pass before any commit
+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
+
+- `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>`.
+- No hardcoded bytes in source. All assets go through Bevy's `AssetServer`.
+- 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.
+
+---
+
+## Code Style
+
+- Use `thiserror` for error types. Never `Box<dyn Error>` in library crates.
+- Prefer `Into<T>` over concrete types in public API function parameters.
+- All public items must have doc comments (`///`). Private items: comment only when non-obvious.
+- Derive order convention: `#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]`
+- 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
+
+- One `Plugin` per major feature: `CardPlugin`, `AudioPlugin`, `AchievementPlugin`, `UIPlugin`, `SyncPlugin`.
+- Resources own shared state. Events communicate between systems. Components own per-entity data.
+- All egui screens live in `solitaire_engine::ui`. Never mix egui and Bevy spawn logic in the same system.
+- Layout is recomputed on `WindowResized` — never assume a fixed window size.
+
+---
+
+## Git Workflow
+
+- Commit after each passing phase, not after every file change.
+- Commit message format: `type(scope): description`
+  - `feat(core): add draw-three mode validation`
+  - `fix(engine): card z-order during drag`
+  - `test(core): undo stack boundary conditions`
+  - `chore(server): add sqlx migration 002`
+- Never commit with failing tests or clippy warnings.
+- Never commit secrets, `.env` files, or `*.db` files.
+
+---
+
+## Ask Before Doing
+
+- Adding a new crate dependency (discuss alternatives first).
+- Changing a type in `solitaire_sync` (breaking change on both client and server).
+- Altering the database schema (requires a new sqlx migration).
+- Introducing `unsafe` code anywhere.
+- Changing the merge strategy in `solitaire_sync::merge()`.
+
+---
+
+## Lessons Learned
+
+> Add entries here when Claude makes a mistake so it isn't repeated.
+
+- 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.
+- `dirs::data_dir()` returns `None` on some minimal Linux environments — always handle the `None` case explicitly, do not unwrap.