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/equipment_stats_panel.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 
+import 'package:askiineverdie/data/game_text_l10n.dart' as l10n;
 import 'package:askiineverdie/src/core/engine/item_service.dart';
 import 'package:askiineverdie/src/core/model/equipment_item.dart';
 import 'package:askiineverdie/src/core/model/equipment_slot.dart';
@@ -135,7 +136,7 @@ class _EmptySlotTile extends StatelessWidget {
       contentPadding: const EdgeInsets.symmetric(horizontal: 8),
       leading: _SlotIcon(slot: slot, isEmpty: true),
       title: Text(
-        '[${_getSlotName(slot)}] (empty)',
+        '[${_getSlotName(slot)}] ${l10n.uiEmpty}',
         style: TextStyle(
           fontSize: 11,
           color: Colors.grey.shade600,
@@ -222,10 +223,7 @@ class _TotalScoreHeader extends StatelessWidget {
       padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 8),
       decoration: BoxDecoration(
         gradient: LinearGradient(
-          colors: [
-            Colors.blueGrey.shade700,
-            Colors.blueGrey.shade600,
-          ],
+          colors: [Colors.blueGrey.shade700, Colors.blueGrey.shade600],
         ),
         borderRadius: BorderRadius.circular(8),
         boxShadow: [
@@ -239,11 +237,7 @@ class _TotalScoreHeader extends StatelessWidget {
       child: Row(
         children: [
           // 장비 아이콘
-          const Icon(
-            Icons.shield,
-            size: 20,
-            color: Colors.white70,
-          ),
+          const Icon(Icons.shield, size: 20, color: Colors.white70),
           const SizedBox(width: 8),
 
           // 총합 점수
@@ -251,12 +245,9 @@ class _TotalScoreHeader extends StatelessWidget {
             child: Column(
               crossAxisAlignment: CrossAxisAlignment.start,
               children: [
-                const Text(
-                  'Equipment Score',
-                  style: TextStyle(
-                    fontSize: 10,
-                    color: Colors.white70,
-                  ),
+                Text(
+                  l10n.uiEquipmentScore,
+                  style: const TextStyle(fontSize: 10, color: Colors.white70),
                 ),
                 Text(
                   '$totalScore',
@@ -304,46 +295,80 @@ class _StatsGrid extends StatelessWidget {
     final entries = <_StatEntry>[];
 
     // 공격 스탯
-    if (stats.atk > 0) entries.add(_StatEntry('ATK', '+${stats.atk}'));
-    if (stats.magAtk > 0) entries.add(_StatEntry('MATK', '+${stats.magAtk}'));
+    if (stats.atk > 0) entries.add(_StatEntry(l10n.statAtk, '+${stats.atk}'));
+    if (stats.magAtk > 0) {
+      entries.add(_StatEntry(l10n.statMAtk, '+${stats.magAtk}'));
+    }
     if (stats.criRate > 0) {
-      entries.add(_StatEntry('CRI', '${(stats.criRate * 100).toStringAsFixed(1)}%'));
+      entries.add(
+        _StatEntry(l10n.statCri, '${(stats.criRate * 100).toStringAsFixed(1)}%'),
+      );
     }
     if (stats.parryRate > 0) {
-      entries.add(_StatEntry('PARRY', '${(stats.parryRate * 100).toStringAsFixed(1)}%'));
+      entries.add(
+        _StatEntry(
+          l10n.statParry,
+          '${(stats.parryRate * 100).toStringAsFixed(1)}%',
+        ),
+      );
     }
 
     // 방어 스탯
-    if (stats.def > 0) entries.add(_StatEntry('DEF', '+${stats.def}'));
-    if (stats.magDef > 0) entries.add(_StatEntry('MDEF', '+${stats.magDef}'));
+    if (stats.def > 0) entries.add(_StatEntry(l10n.statDef, '+${stats.def}'));
+    if (stats.magDef > 0) {
+      entries.add(_StatEntry(l10n.statMDef, '+${stats.magDef}'));
+    }
     if (stats.blockRate > 0) {
-      entries.add(_StatEntry('BLOCK', '${(stats.blockRate * 100).toStringAsFixed(1)}%'));
+      entries.add(
+        _StatEntry(
+          l10n.statBlock,
+          '${(stats.blockRate * 100).toStringAsFixed(1)}%',
+        ),
+      );
     }
     if (stats.evasion > 0) {
-      entries.add(_StatEntry('EVA', '${(stats.evasion * 100).toStringAsFixed(1)}%'));
+      entries.add(
+        _StatEntry(l10n.statEva, '${(stats.evasion * 100).toStringAsFixed(1)}%'),
+      );
     }
 
     // 자원 스탯
-    if (stats.hpBonus > 0) entries.add(_StatEntry('HP', '+${stats.hpBonus}'));
-    if (stats.mpBonus > 0) entries.add(_StatEntry('MP', '+${stats.mpBonus}'));
+    if (stats.hpBonus > 0) {
+      entries.add(_StatEntry(l10n.statHp, '+${stats.hpBonus}'));
+    }
+    if (stats.mpBonus > 0) {
+      entries.add(_StatEntry(l10n.statMp, '+${stats.mpBonus}'));
+    }
 
     // 능력치 보너스
-    if (stats.strBonus > 0) entries.add(_StatEntry('STR', '+${stats.strBonus}'));
-    if (stats.conBonus > 0) entries.add(_StatEntry('CON', '+${stats.conBonus}'));
-    if (stats.dexBonus > 0) entries.add(_StatEntry('DEX', '+${stats.dexBonus}'));
-    if (stats.intBonus > 0) entries.add(_StatEntry('INT', '+${stats.intBonus}'));
-    if (stats.wisBonus > 0) entries.add(_StatEntry('WIS', '+${stats.wisBonus}'));
-    if (stats.chaBonus > 0) entries.add(_StatEntry('CHA', '+${stats.chaBonus}'));
+    if (stats.strBonus > 0) {
+      entries.add(_StatEntry(l10n.statStr, '+${stats.strBonus}'));
+    }
+    if (stats.conBonus > 0) {
+      entries.add(_StatEntry(l10n.statCon, '+${stats.conBonus}'));
+    }
+    if (stats.dexBonus > 0) {
+      entries.add(_StatEntry(l10n.statDex, '+${stats.dexBonus}'));
+    }
+    if (stats.intBonus > 0) {
+      entries.add(_StatEntry(l10n.statInt, '+${stats.intBonus}'));
+    }
+    if (stats.wisBonus > 0) {
+      entries.add(_StatEntry(l10n.statWis, '+${stats.wisBonus}'));
+    }
+    if (stats.chaBonus > 0) {
+      entries.add(_StatEntry(l10n.statCha, '+${stats.chaBonus}'));
+    }
 
     // 무기 공속
     if (slot == EquipmentSlot.weapon && stats.attackSpeed > 0) {
-      entries.add(_StatEntry('SPEED', '${stats.attackSpeed}ms'));
+      entries.add(_StatEntry(l10n.statSpeed, '${stats.attackSpeed}ms'));
     }
 
     if (entries.isEmpty) {
-      return const Text(
-        'No bonus stats',
-        style: TextStyle(fontSize: 10, color: Colors.grey),
+      return Text(
+        l10n.uiNoBonusStats,
+        style: const TextStyle(fontSize: 10, color: Colors.grey),
       );
     }
 
@@ -406,7 +431,7 @@ class _ItemMetaRow extends StatelessWidget {
     return Row(
       children: [
         Text(
-          'Lv.${item.level}',
+          l10n.uiLevel(item.level),
           style: const TextStyle(fontSize: 9, color: Colors.grey),
         ),
         const SizedBox(width: 8),
@@ -420,7 +445,7 @@ class _ItemMetaRow extends StatelessWidget {
         ),
         const SizedBox(width: 8),
         Text(
-          'Wt.${item.weight}',
+          l10n.uiWeight(item.weight),
           style: const TextStyle(fontSize: 9, color: Colors.grey),
         ),
       ],
@@ -441,16 +466,16 @@ class _ItemMetaRow extends StatelessWidget {
 /// 슬롯 이름 반환
 String _getSlotName(EquipmentSlot slot) {
   return switch (slot) {
-    EquipmentSlot.weapon => 'Weapon',
-    EquipmentSlot.shield => 'Shield',
-    EquipmentSlot.helm => 'Helm',
-    EquipmentSlot.hauberk => 'Hauberk',
-    EquipmentSlot.brassairts => 'Brassairts',
-    EquipmentSlot.vambraces => 'Vambraces',
-    EquipmentSlot.gauntlets => 'Gauntlets',
-    EquipmentSlot.gambeson => 'Gambeson',
-    EquipmentSlot.cuisses => 'Cuisses',
-    EquipmentSlot.greaves => 'Greaves',
-    EquipmentSlot.sollerets => 'Sollerets',
+    EquipmentSlot.weapon => l10n.slotWeapon,
+    EquipmentSlot.shield => l10n.slotShield,
+    EquipmentSlot.helm => l10n.slotHelm,
+    EquipmentSlot.hauberk => l10n.slotHauberk,
+    EquipmentSlot.brassairts => l10n.slotBrassairts,
+    EquipmentSlot.vambraces => l10n.slotVambraces,
+    EquipmentSlot.gauntlets => l10n.slotGauntlets,
+    EquipmentSlot.gambeson => l10n.slotGambeson,
+    EquipmentSlot.cuisses => l10n.slotCuisses,
+    EquipmentSlot.greaves => l10n.slotGreaves,
+    EquipmentSlot.sollerets => l10n.slotSollerets,
   };
 }