feat(engine): wire AnimSpeed to animation, new achievements, leaderboard opt-in, daily goal display

- AnimSpeed setting now drives card slide duration (Normal=0.15s, Fast=0.07s, Instant=snap);
  EffectiveSlideDuration resource updated on SettingsChangedEvent; AnimSpeed row added to Settings panel
- GameState.recycle_count tracks waste recycles; perfectionist/comeback/zen_winner achievements added
  with full unit tests
- SyncProvider gains opt_in_leaderboard(); SolitaireServerClient implements POST /api/leaderboard/opt-in;
  Opt In button added to leaderboard panel
- DailyChallengeResource stores goal_description/target_score/max_time_secs from server;
  pressing C shows goal description as toast (DailyGoalAnnouncementEvent)

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

solitaire_engine/src/achievement_plugin.rs

@@ -114,6 +114,8 @@ fn evaluate_on_win(
         last_win_time_seconds: ev.time_seconds,
         last_win_used_undo: game.0.undo_count > 0,
         wall_clock_hour: Some(Local::now().hour()),
+        last_win_recycle_count: game.0.recycle_count,
+        last_win_is_zen: game.0.mode == solitaire_core::game_state::GameMode::Zen,
     };
 
     let hits = check_achievements(&ctx);