refactor(core): 코어 엔진 및 모델 개선

- 애니메이션 시스템 개선
- 오디오 서비스 개선
- 전투/스킬/포션 서비스 개선
- 스토리지 및 저장 시스템 개선
- 모델 클래스 타입 안정성 강화

lib/src/core/engine/progress_loop.dart

@@ -1,8 +1,8 @@
 import 'dart:async';
 
-import 'package:askiineverdie/src/core/model/game_state.dart';
-import 'package:askiineverdie/src/core/storage/save_manager.dart';
-import 'package:askiineverdie/src/core/engine/progress_service.dart';
+import 'package:asciineverdie/src/core/model/game_state.dart';
+import 'package:asciineverdie/src/core/storage/save_manager.dart';
+import 'package:asciineverdie/src/core/engine/progress_service.dart';
 
 class AutoSaveConfig {
   const AutoSaveConfig({
@@ -40,11 +40,13 @@ class ProgressLoop {
     DateTime Function()? now,
     this.cheatsEnabled = false,
     this.onPlayerDied,
+    List<int> availableSpeeds = const [1, 5],
   }) : _state = initialState,
        _tickInterval = tickInterval,
        _autoSaveConfig = autoSaveConfig,
        _now = now ?? DateTime.now,
-       _stateController = StreamController<GameState>.broadcast();
+       _stateController = StreamController<GameState>.broadcast(),
+       _availableSpeeds = availableSpeeds.isNotEmpty ? availableSpeeds : [1];
 
   final ProgressService progressService;
   final SaveManager? saveManager;
@@ -60,21 +62,35 @@ class ProgressLoop {
   Timer? _timer;
   int? _lastTickMs;
   int _speedMultiplier = 1;
+  List<int> _availableSpeeds;
 
   GameState get current => _state;
   Stream<GameState> get stream => _stateController.stream;
   GameState _state;
 
-  /// 현재 배속 (1x, 3x, 10x)
+  /// 가용 배속 목록
+  List<int> get availableSpeeds => List.unmodifiable(_availableSpeeds);
+
+  /// 현재 배속 (1x, 2x, 5x)
   int get speedMultiplier => _speedMultiplier;
 
-  /// 배속 순환: 1 -> 3 -> 10 -> 1
+  /// 배속 순환: 가용 배속 목록 순환
+  /// 명예의 전당에 캐릭터 없으면: 1 -> 5 -> 1
+  /// 명예의 전당에 캐릭터 있으면: 1 -> 2 -> 5 -> 1
   void cycleSpeed() {
-    _speedMultiplier = switch (_speedMultiplier) {
-      1 => 3,
-      3 => 10,
-      _ => 1,
-    };
+    final currentIndex = _availableSpeeds.indexOf(_speedMultiplier);
+    final nextIndex = (currentIndex + 1) % _availableSpeeds.length;
+    _speedMultiplier = _availableSpeeds[nextIndex];
+  }
+
+  /// 가용 배속 목록 업데이트 (명예의 전당 상태 변경 시)
+  void updateAvailableSpeeds(List<int> speeds) {
+    if (speeds.isEmpty) return;
+    _availableSpeeds = speeds;
+    // 현재 배속이 새 목록에 없으면 첫 번째로 리셋
+    if (!_availableSpeeds.contains(_speedMultiplier)) {
+      _speedMultiplier = _availableSpeeds.first;
+    }
   }
 
   void start() {