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/stats_plugin.rs

@@ -11,7 +11,8 @@ use std::path::PathBuf;
 use bevy::input::ButtonInput;
 use bevy::prelude::*;
 use solitaire_data::{
-    load_stats_from, save_stats_to, stats_file_path, PlayerProgress, StatsSnapshot, WEEKLY_GOALS,
+    load_stats_from, save_stats_to, stats_file_path, PlayerProgress, StatsExt, StatsSnapshot,
+    WEEKLY_GOALS,
 };
 
 use crate::events::{GameWonEvent, NewGameRequestEvent};