feat(workspace): full server + sync implementation, all tests green

- solitaire_server: Axum auth, sync push/pull, leaderboard, daily
  challenge, account deletion, JWT middleware, rate limiting via
  tower_governor, SQLite migrations, health endpoint
- solitaire_server: expose build_test_router (no rate limiting) so
  integration tests work without a peer IP in oneshot requests
- solitaire_sync: SyncPayload, merge logic, shared API types
- solitaire_data: SyncProvider trait, LocalOnlyProvider,
  SolitaireServerClient, auth_tokens keyring integration, blanket
  Box<dyn SyncProvider> impl
- solitaire_data/settings: derive Default on SyncBackend (clippy fix)
- .sqlx/: offline query cache so server compiles without a live DB
- sqlx: removed non-existent "offline" feature flag
- keyring v2: fixed Entry::new() returning Result<Entry>
- sqlx 0.8: all SQLite TEXT columns wrapped in Option<T>
- Integration tests: max_connections(1) on in-memory pool so all
  connections share the same schema

All 191 tests pass; cargo clippy -D warnings clean.

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

solitaire_engine/src/events.rs

@@ -3,6 +3,7 @@
 use bevy::prelude::Event;
 use solitaire_core::game_state::GameMode;
 use solitaire_core::pile::PileType;
+use solitaire_data::AchievementRecord;
 
 /// Request to move `count` cards from `from` to `to`. Fired by input systems,
 /// consumed by `GamePlugin`.
@@ -55,8 +56,8 @@ pub struct GameWonEvent {
 #[derive(Event, Debug, Clone, Copy)]
 pub struct CardFlippedEvent(pub u32);
 
-/// Achievement unlocked notification — name of the achievement.
-///
-/// Uses `String` as a placeholder; replaced with `AchievementRecord` in Phase 5.
+/// Achievement unlocked notification carrying the full `AchievementRecord` for
+/// the newly unlocked achievement. Consumed by the toast renderer and any
+/// persistence/UI systems that need unlock metadata.
 #[derive(Event, Debug, Clone)]
-pub struct AchievementUnlockedEvent(pub String);
+pub struct AchievementUnlockedEvent(pub AchievementRecord);