feat(game): 게임 시스템 전면 개편 및 다국어 지원 확장

## 스킬 시스템 개선
- skill_data.dart: 스킬 데이터 구조 전면 개편 (+1176 라인)
- skill_service.dart: 스킬 발동 로직 확장 및 버프 시스템 연동
- skill.dart: 스킬 모델 개선, 쿨다운/효과 타입 추가

## Canvas 애니메이션 리팩토링
- battle_composer.dart 삭제 (레거시 위젯 기반 렌더러)
- monster_colors.dart 삭제 (AsciiCell 색상 시스템으로 통합)
- canvas_battle_composer.dart: z-index 정렬 (몬스터 z=1, 캐릭터 z=2, 이펙트 z=3)
- ascii_cell.dart, ascii_layer.dart: 코드 정리

## UI/UX 개선
- hp_mp_bar.dart: l10n 적용, 몬스터 HP 바 컴팩트화
- death_overlay.dart: 사망 화면 개선
- equipment_stats_panel.dart: 장비 스탯 표시 확장
- active_buff_panel.dart: 버프 패널 개선
- notification_overlay.dart: 알림 시스템 개선

## 다국어 지원 확장
- game_text_l10n.dart: 게임 텍스트 통합 (+758 라인)
- 한국어/일본어/영어/중국어 번역 업데이트
- ARB 파일 동기화

## 게임 로직 개선
- progress_service.dart: 진행 로직 리팩토링
- combat_calculator.dart: 전투 계산 로직 개선
- stat_calculator.dart: 스탯 계산 시스템 개선
- story_service.dart: 스토리 진행 로직 개선

## 기타
- theme_preferences.dart 삭제 (미사용)
- 테스트 파일 업데이트
- class_data.dart: 클래스 데이터 정리

lib/src/features/game/widgets/death_overlay.dart

@@ -1,5 +1,7 @@
 import 'package:flutter/material.dart';
 
+import 'package:askiineverdie/data/game_text_l10n.dart' as l10n;
+import 'package:askiineverdie/src/core/l10n/game_data_l10n.dart';
 import 'package:askiineverdie/src/core/model/combat_event.dart';
 import 'package:askiineverdie/src/core/model/game_state.dart';
 
@@ -109,7 +111,7 @@ class DeathOverlay extends StatelessWidget {
         ),
         const SizedBox(height: 16),
         Text(
-          'YOU DIED',
+          l10n.deathYouDied,
           style: TextStyle(
             fontSize: 32,
             fontWeight: FontWeight.bold,
@@ -133,7 +135,7 @@ class DeathOverlay extends StatelessWidget {
         ),
         const SizedBox(height: 4),
         Text(
-          'Level ${deathInfo.levelAtDeath} ${traits.klass}',
+          'Level ${deathInfo.levelAtDeath} ${GameDataL10n.getKlassName(context, traits.klass)}',
           style: theme.textTheme.bodyLarge?.copyWith(
             color: theme.colorScheme.onSurfaceVariant,
           ),
@@ -174,9 +176,9 @@ class DeathOverlay extends StatelessWidget {
 
   String _getDeathCauseText() {
     return switch (deathInfo.cause) {
-      DeathCause.monster => 'Killed by ${deathInfo.killerName}',
-      DeathCause.selfDamage => 'Self-inflicted damage',
-      DeathCause.environment => 'Environmental hazard',
+      DeathCause.monster => l10n.deathKilledBy(deathInfo.killerName),
+      DeathCause.selfDamage => l10n.deathSelfInflicted,
+      DeathCause.environment => l10n.deathEnvironmentalHazard,
     };
   }
 
@@ -210,7 +212,7 @@ class DeathOverlay extends StatelessWidget {
                     crossAxisAlignment: CrossAxisAlignment.start,
                     children: [
                       Text(
-                        'Sacrificed to Resurrect',
+                        l10n.deathSacrificedToResurrect,
                         style: theme.textTheme.labelSmall?.copyWith(
                           color: theme.colorScheme.onSurfaceVariant,
                         ),
@@ -234,8 +236,8 @@ class DeathOverlay extends StatelessWidget {
           _buildInfoRow(
             context,
             icon: Icons.check_circle_outline,
-            label: 'Equipment',
-            value: 'No sacrifice needed',
+            label: l10n.deathEquipment,
+            value: l10n.deathNoSacrificeNeeded,
             isNegative: false,
           ),
           const SizedBox(height: 8),
@@ -243,7 +245,7 @@ class DeathOverlay extends StatelessWidget {
         _buildInfoRow(
           context,
           icon: Icons.monetization_on_outlined,
-          label: 'Gold Remaining',
+          label: l10n.deathGoldRemaining,
           value: _formatGold(deathInfo.goldAtDeath),
           isNegative: false,
         ),
@@ -306,7 +308,7 @@ class DeathOverlay extends StatelessWidget {
       child: FilledButton.icon(
         onPressed: onResurrect,
         icon: const Icon(Icons.replay),
-        label: const Text('Resurrect'),
+        label: Text(l10n.deathResurrect),
         style: FilledButton.styleFrom(
           backgroundColor: theme.colorScheme.primary,
           padding: const EdgeInsets.symmetric(vertical: 16),
@@ -324,7 +326,7 @@ class DeathOverlay extends StatelessWidget {
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
         Text(
-          'Combat Log',
+          l10n.deathCombatLog,
           style: theme.textTheme.labelMedium?.copyWith(
             color: theme.colorScheme.onSurfaceVariant,
             fontWeight: FontWeight.bold,
@@ -378,69 +380,70 @@ class DeathOverlay extends StatelessWidget {
 
   /// 전투 이벤트를 아이콘, 색상, 메시지로 포맷
   (IconData, Color, String) _formatCombatEvent(CombatEvent event) {
+    final target = event.targetName ?? '';
     return switch (event.type) {
       CombatEventType.playerAttack => (
-          event.isCritical ? Icons.flash_on : Icons.local_fire_department,
-          event.isCritical ? Colors.yellow.shade300 : Colors.green.shade300,
-          event.isCritical
-              ? 'CRITICAL! ${event.damage} damage to ${event.targetName}'
-              : 'Hit ${event.targetName} for ${event.damage} damage',
-        ),
+        event.isCritical ? Icons.flash_on : Icons.local_fire_department,
+        event.isCritical ? Colors.yellow.shade300 : Colors.green.shade300,
+        event.isCritical
+            ? l10n.combatCritical(event.damage, target)
+            : l10n.combatYouHit(target, event.damage),
+      ),
       CombatEventType.monsterAttack => (
-          Icons.dangerous,
-          Colors.red.shade300,
-          '${event.targetName} hits you for ${event.damage} damage',
-        ),
+        Icons.dangerous,
+        Colors.red.shade300,
+        l10n.combatMonsterHitsYou(target, event.damage),
+      ),
       CombatEventType.playerEvade => (
-          Icons.directions_run,
-          Colors.cyan.shade300,
-          'Evaded attack from ${event.targetName}',
-        ),
+        Icons.directions_run,
+        Colors.cyan.shade300,
+        l10n.combatEvadedAttackFrom(target),
+      ),
       CombatEventType.monsterEvade => (
-          Icons.directions_run,
-          Colors.orange.shade300,
-          '${event.targetName} evaded your attack',
-        ),
+        Icons.directions_run,
+        Colors.orange.shade300,
+        l10n.combatMonsterEvaded(target),
+      ),
       CombatEventType.playerBlock => (
-          Icons.shield,
-          Colors.blueGrey.shade300,
-          'Blocked ${event.targetName}\'s attack (${event.damage} reduced)',
-        ),
+        Icons.shield,
+        Colors.blueGrey.shade300,
+        l10n.combatBlockedAttack(target, event.damage),
+      ),
       CombatEventType.playerParry => (
-          Icons.sports_kabaddi,
-          Colors.teal.shade300,
-          'Parried ${event.targetName}\'s attack (${event.damage} reduced)',
-        ),
+        Icons.sports_kabaddi,
+        Colors.teal.shade300,
+        l10n.combatParriedAttack(target, event.damage),
+      ),
       CombatEventType.playerSkill => (
-          Icons.auto_fix_high,
-          Colors.purple.shade300,
-          '${event.skillName} deals ${event.damage} damage',
-        ),
+        Icons.auto_fix_high,
+        Colors.purple.shade300,
+        l10n.combatSkillDamage(event.skillName ?? '', event.damage),
+      ),
       CombatEventType.playerHeal => (
-          Icons.healing,
-          Colors.green.shade300,
-          'Healed for ${event.healAmount} HP',
-        ),
+        Icons.healing,
+        Colors.green.shade300,
+        l10n.combatHealedFor(event.healAmount),
+      ),
       CombatEventType.playerBuff => (
-          Icons.trending_up,
-          Colors.lightBlue.shade300,
-          '${event.skillName} activated',
-        ),
+        Icons.trending_up,
+        Colors.lightBlue.shade300,
+        l10n.combatBuffActivated(event.skillName ?? ''),
+      ),
       CombatEventType.dotTick => (
-          Icons.whatshot,
-          Colors.deepOrange.shade300,
-          '${event.skillName} ticks for ${event.damage} damage',
-        ),
+        Icons.whatshot,
+        Colors.deepOrange.shade300,
+        l10n.combatDotTick(event.skillName ?? '', event.damage),
+      ),
       CombatEventType.playerPotion => (
-          Icons.local_drink,
-          Colors.lightGreen.shade300,
-          '${event.skillName}: +${event.healAmount} ${event.targetName}',
-        ),
+        Icons.local_drink,
+        Colors.lightGreen.shade300,
+        l10n.combatPotionUsed(event.skillName ?? '', event.healAmount, target),
+      ),
       CombatEventType.potionDrop => (
-          Icons.card_giftcard,
-          Colors.lime.shade300,
-          'Dropped: ${event.skillName}',
-        ),
+        Icons.card_giftcard,
+        Colors.lime.shade300,
+        l10n.combatPotionDrop(event.skillName ?? ''),
+      ),
     };
   }
 }