refactor(core): 진행 루프, 저장 데이터, 저장 관리자 개선

- ProgressLoop 로직 정리
- SaveData 모델 확장
- SaveManager 개선

lib/src/core/engine/progress_loop.dart

@@ -108,7 +108,7 @@ class ProgressLoop {
     _timer?.cancel();
     _timer = null;
     if (saveOnStop && _autoSaveConfig.onStop && saveManager != null) {
-      await saveManager!.saveState(_state);
+      await saveManager!.saveState(_state, cheatsEnabled: cheatsEnabled);
     }
   }
 
@@ -131,7 +131,7 @@ class ProgressLoop {
     _stateController.add(_state);
 
     if (saveManager != null && _autoSaveConfig.shouldSave(result)) {
-      saveManager!.saveState(_state);
+      saveManager!.saveState(_state, cheatsEnabled: cheatsEnabled);
     }
 
     // 사망 시 루프 정지 및 콜백 호출 (Phase 4)

lib/src/core/model/save_data.dart

@@ -16,9 +16,10 @@ class GameSave {
     required this.skillBook,
     required this.progress,
     required this.queue,
+    this.cheatsEnabled = false,
   });
 
-  factory GameSave.fromState(GameState state) {
+  factory GameSave.fromState(GameState state, {bool cheatsEnabled = false}) {
     return GameSave(
       version: kSaveVersion,
       rngState: state.rng.state,
@@ -29,6 +30,7 @@ class GameSave {
       skillBook: state.skillBook,
       progress: state.progress,
       queue: state.queue,
+      cheatsEnabled: cheatsEnabled,
     );
   }
 
@@ -41,10 +43,12 @@ class GameSave {
   final SkillBook skillBook;
   final ProgressState progress;
   final QueueState queue;
+  final bool cheatsEnabled;
 
   Map<String, dynamic> toJson() {
     return {
       'version': version,
+      'cheatsEnabled': cheatsEnabled,
       'rng': rngState,
       'traits': {
         'name': traits.name,
@@ -144,6 +148,7 @@ class GameSave {
 
     return GameSave(
       version: json['version'] as int? ?? kSaveVersion,
+      cheatsEnabled: json['cheatsEnabled'] as bool? ?? false,
       rngState: json['rng'] as int? ?? 0,
       traits: Traits(
         name: traitsJson['name'] as String? ?? '',

lib/src/core/storage/save_manager.dart

@@ -13,19 +13,23 @@ class SaveManager {
 
   /// Save current game state to disk. [fileName] may be absolute or relative.
   /// Returns outcome with error on failure.
-  Future<SaveOutcome> saveState(GameState state, {String? fileName}) {
-    final save = GameSave.fromState(state);
+  Future<SaveOutcome> saveState(
+    GameState state, {
+    String? fileName,
+    bool cheatsEnabled = false,
+  }) {
+    final save = GameSave.fromState(state, cheatsEnabled: cheatsEnabled);
     return _repo.save(save, fileName ?? defaultFileName);
   }
 
   /// Load game state from disk. [fileName] may be absolute (e.g., file picker).
-  /// Returns outcome + optional state.
-  Future<(SaveOutcome, GameState?)> loadState({String? fileName}) async {
+  /// Returns outcome + optional state + cheatsEnabled flag.
+  Future<(SaveOutcome, GameState?, bool)> loadState({String? fileName}) async {
     final (outcome, save) = await _repo.load(fileName ?? defaultFileName);
     if (!outcome.success || save == null) {
-      return (outcome, null);
+      return (outcome, null, false);
     }
-    return (outcome, save.toState());
+    return (outcome, save.toState(), save.cheatsEnabled);
   }
 
   /// 저장 파일 목록 조회