feat(death): 사망/부활 시스템 개선

- DeathInfo에 lostItem 필드 추가 (광고 부활 시 복구용)
- 세이브 데이터 v4: MonetizationState 포함
- 사망 오버레이 UI 개선
- 부활 서비스 광고 연동

lib/src/core/engine/resurrection_service.dart

@@ -240,6 +240,129 @@ class ResurrectionService {
     return state.inventory.gold >= cost;
   }
 
+  // ============================================================================
+  // 광고 부활 (HP 100% + 아이템 복구)
+  // ============================================================================
+
+  /// 광고 부활 처리
+  ///
+  /// 1. 상실한 아이템 복구 (있는 경우)
+  /// 2. HP/MP 100% 회복
+  /// 3. 사망 상태 해제
+  /// 4. 안전 지역으로 이동 태스크 설정
+  ///
+  /// Note: 10분 자동부활 버프는 GameSessionController에서 처리
+  GameState processAdRevive(GameState state) {
+    if (!state.isDead) return state;
+
+    var nextState = state;
+
+    // 1. 상실한 아이템 복구 (있는 경우)
+    if (canRecoverLostItem(state)) {
+      nextState = processItemRecovery(nextState);
+    }
+
+    // 2. 전체 HP/MP 계산 (장비 + 종족 + 클래스 보너스 포함)
+    final totalHpMax = _calculateTotalHpMax(nextState);
+    final totalMpMax = _calculateTotalMpMax(nextState);
+
+    // HP/MP 100% 회복 (장비 구매 없이)
+    nextState = nextState.copyWith(
+      stats: nextState.stats.copyWith(
+        hpCurrent: totalHpMax,
+        mpCurrent: totalMpMax,
+      ),
+      clearDeathInfo: true, // 사망 상태 해제
+    );
+
+    // 스킬 쿨타임 초기화
+    nextState = nextState.copyWith(
+      skillSystem: SkillSystemState.empty().copyWith(
+        elapsedMs: nextState.skillSystem.elapsedMs,
+      ),
+    );
+
+    // 4. 부활 후 태스크 시퀀스 설정
+    final resurrectionQueue = <QueueEntry>[
+      QueueEntry(
+        kind: QueueKind.task,
+        durationMillis: 3000,
+        caption: l10n.taskReturningToTown,
+        taskType: TaskType.neutral,
+      ),
+      QueueEntry(
+        kind: QueueKind.task,
+        durationMillis: 3000,
+        caption: l10n.taskRestockingAtShop,
+        taskType: TaskType.market,
+      ),
+      QueueEntry(
+        kind: QueueKind.task,
+        durationMillis: 2000,
+        caption: l10n.taskHeadingToHuntingGrounds,
+        taskType: TaskType.neutral,
+      ),
+    ];
+
+    final firstTask = resurrectionQueue.removeAt(0);
+    nextState = nextState.copyWith(
+      queue: QueueState(entries: resurrectionQueue),
+      progress: nextState.progress.copyWith(
+        currentTask: TaskInfo(
+          caption: firstTask.caption,
+          type: firstTask.taskType,
+        ),
+        task: ProgressBarState(position: 0, max: firstTask.durationMillis),
+        currentCombat: null,
+      ),
+    );
+
+    return nextState;
+  }
+
+  // ============================================================================
+  // 아이템 복구 (Phase 5)
+  // ============================================================================
+
+  /// 상실한 아이템 복구 가능 여부 확인
+  ///
+  /// 사망 상태이고 상실한 아이템이 있을 때만 true
+  bool canRecoverLostItem(GameState state) {
+    if (!state.isDead) return false;
+    if (state.deathInfo == null) return false;
+    return state.deathInfo!.lostItem != null;
+  }
+
+  /// 상실한 아이템 복구 처리
+  ///
+  /// 광고 시청 후 호출되며 상실한 아이템을 장비에 복원합니다.
+  /// Returns: 복구된 상태 (복구 불가 시 원본 상태 반환)
+  GameState processItemRecovery(GameState state) {
+    if (!canRecoverLostItem(state)) return state;
+
+    final deathInfo = state.deathInfo!;
+    final lostItem = deathInfo.lostItem!;
+    final lostSlot = deathInfo.lostItemSlot!;
+
+    // 해당 슬롯에 아이템 복원
+    final slotIndex = lostSlot.index;
+    final updatedEquipment = state.equipment.setItemByIndex(slotIndex, lostItem);
+
+    // DeathInfo에서 상실 아이템 정보 제거 (복구 완료)
+    final updatedDeathInfo = deathInfo.copyWith(
+      lostEquipmentCount: 0,
+      lostItemName: null,
+      lostItemSlot: null,
+      lostItemRarity: null,
+      lostItem: null,
+    );
+
+    return state.copyWith(
+      equipment: updatedEquipment,
+      deathInfo: updatedDeathInfo,
+    );
+  }
+
   /// 장비 보존 아이템 적용 (향후 확장용)
   ///
   /// [protectedSlots] 보존할 슬롯 인덱스 목록

lib/src/core/model/game_state.dart

@@ -133,6 +133,7 @@ class DeathInfo {
     this.lostItemName,
     this.lostItemSlot,
     this.lostItemRarity,
+    this.lostItem,
     this.lastCombatEvents = const [],
   });
 
@@ -154,6 +155,9 @@ class DeathInfo {
   /// 제물로 바친 아이템 희귀도 (null이면 없음)
   final ItemRarity? lostItemRarity;
 
+  /// 상실한 장비 전체 정보 (광고 부활 시 복구용)
+  final EquipmentItem? lostItem;
+
   /// 사망 시점 골드
   final int goldAtDeath;
 
@@ -173,6 +177,7 @@ class DeathInfo {
     String? lostItemName,
     EquipmentSlot? lostItemSlot,
     ItemRarity? lostItemRarity,
+    EquipmentItem? lostItem,
     int? goldAtDeath,
     int? levelAtDeath,
     int? timestamp,
@@ -185,6 +190,7 @@ class DeathInfo {
       lostItemName: lostItemName ?? this.lostItemName,
       lostItemSlot: lostItemSlot ?? this.lostItemSlot,
       lostItemRarity: lostItemRarity ?? this.lostItemRarity,
+      lostItem: lostItem ?? this.lostItem,
       goldAtDeath: goldAtDeath ?? this.goldAtDeath,
       levelAtDeath: levelAtDeath ?? this.levelAtDeath,
       timestamp: timestamp ?? this.timestamp,

lib/src/core/model/save_data.dart

@@ -2,6 +2,7 @@ import 'dart:collection';
 
 import 'package:asciineverdie/src/core/model/equipment_item.dart';
 import 'package:asciineverdie/src/core/model/equipment_slot.dart';
+import 'package:asciineverdie/src/core/model/monetization_state.dart';
 import 'package:asciineverdie/src/core/model/monster_grade.dart';
 import 'package:asciineverdie/src/core/util/deterministic_random.dart';
 import 'package:asciineverdie/src/core/model/game_state.dart';
@@ -9,7 +10,8 @@ import 'package:asciineverdie/src/core/model/game_state.dart';
 /// 세이브 파일 버전
 /// - v2: 장비 이름만 저장 (레거시)
 /// - v3: 장비 전체 정보 저장 (level, rarity, stats 포함)
-const int kSaveVersion = 3;
+/// - v4: MonetizationState 추가, DeathInfo.lostItem 추가
+const int kSaveVersion = 4;
 
 class GameSave {
   GameSave({
@@ -23,9 +25,14 @@ class GameSave {
     required this.progress,
     required this.queue,
     this.cheatsEnabled = false,
+    this.monetization,
   });
 
-  factory GameSave.fromState(GameState state, {bool cheatsEnabled = false}) {
+  factory GameSave.fromState(
+    GameState state, {
+    bool cheatsEnabled = false,
+    MonetizationState? monetization,
+  }) {
     return GameSave(
       version: kSaveVersion,
       rngState: state.rng.state,
@@ -37,6 +44,7 @@ class GameSave {
       progress: state.progress,
       queue: state.queue,
       cheatsEnabled: cheatsEnabled,
+      monetization: monetization,
     );
   }
 
@@ -51,6 +59,9 @@ class GameSave {
   final QueueState queue;
   final bool cheatsEnabled;
 
+  /// 수익화 시스템 상태 (v4+)
+  final MonetizationState? monetization;
+
   Map<String, dynamic> toJson() {
     return {
       'version': version,
@@ -132,6 +143,7 @@ class GameSave {
             },
           )
           .toList(),
+      if (monetization != null) 'monetization': monetization!.toJson(),
     };
   }
 
@@ -244,6 +256,9 @@ class GameSave {
           }),
         ),
       ),
+      monetization: _monetizationFromJson(
+        json['monetization'] as Map<String, dynamic>?,
+      ),
     );
   }
 
@@ -355,3 +370,12 @@ Equipment _equipmentFromJson(Map<String, dynamic> json, int version) {
     bestIndex: json['bestIndex'] as int? ?? 0,
   );
 }
+
+/// MonetizationState 역직렬화 (v4+ 마이그레이션)
+///
+/// - v3 이하: null (기본값 사용)
+/// - v4 이상: 저장된 상태 로드
+MonetizationState? _monetizationFromJson(Map<String, dynamic>? json) {
+  if (json == null) return null;
+  return MonetizationState.fromJson(json);
+}

lib/src/core/storage/save_manager.dart

@@ -1,4 +1,5 @@
 import 'package:asciineverdie/src/core/model/game_state.dart';
+import 'package:asciineverdie/src/core/model/monetization_state.dart';
 import 'package:asciineverdie/src/core/model/save_data.dart';
 import 'package:asciineverdie/src/core/storage/save_repository.dart';
 import 'package:asciineverdie/src/core/storage/save_service.dart'
@@ -13,23 +14,36 @@ class SaveManager {
 
   /// Save current game state to disk. [fileName] may be absolute or relative.
   /// Returns outcome with error on failure.
+  ///
+  /// [monetization] 저장 시 lastPlayTime을 현재 시간으로 자동 업데이트
   Future<SaveOutcome> saveState(
     GameState state, {
     String? fileName,
     bool cheatsEnabled = false,
+    MonetizationState? monetization,
   }) {
-    final save = GameSave.fromState(state, cheatsEnabled: cheatsEnabled);
+    // lastPlayTime을 현재 시간으로 업데이트
+    final updatedMonetization = (monetization ?? MonetizationState.initial())
+        .copyWith(lastPlayTime: DateTime.now());
+
+    final save = GameSave.fromState(
+      state,
+      cheatsEnabled: cheatsEnabled,
+      monetization: updatedMonetization,
+    );
     return _repo.save(save, fileName ?? defaultFileName);
   }
 
   /// Load game state from disk. [fileName] may be absolute (e.g., file picker).
-  /// Returns outcome + optional state + cheatsEnabled flag.
-  Future<(SaveOutcome, GameState?, bool)> loadState({String? fileName}) async {
+  /// Returns outcome + optional state + cheatsEnabled flag + monetization state.
+  Future<(SaveOutcome, GameState?, bool, MonetizationState?)> loadState({
+    String? fileName,
+  }) async {
     final (outcome, save) = await _repo.load(fileName ?? defaultFileName);
     if (!outcome.success || save == null) {
-      return (outcome, null, false);
+      return (outcome, null, false, null);
     }
-    return (outcome, save.toState(), save.cheatsEnabled);
+    return (outcome, save.toState(), save.cheatsEnabled, save.monetization);
   }
 
   /// 저장 파일 목록 조회