feat(game): 포션 시스템 및 UI 패널 추가

- 포션 시스템 구현 (PotionService, Potion 모델)
- 포션 인벤토리 패널 위젯
- 활성 버프 패널 위젯
- 장비 스탯 패널 위젯
- 스킬 시스템 확장
- 일본어 번역 추가
- 전투 이벤트/상태 모델 개선

lib/src/features/game/game_play_screen.dart

@@ -20,7 +20,10 @@ import 'package:askiineverdie/src/features/game/widgets/hp_mp_bar.dart';
 import 'package:askiineverdie/src/features/game/widgets/notification_overlay.dart';
 import 'package:askiineverdie/src/features/game/widgets/skill_panel.dart';
 import 'package:askiineverdie/src/features/game/widgets/stats_panel.dart';
+import 'package:askiineverdie/src/features/game/widgets/equipment_stats_panel.dart';
+import 'package:askiineverdie/src/features/game/widgets/potion_inventory_panel.dart';
 import 'package:askiineverdie/src/features/game/widgets/task_progress_panel.dart';
+import 'package:askiineverdie/src/features/game/widgets/active_buff_panel.dart';
 
 /// 게임 진행 화면 (Main.dfm 기반 3패널 레이아웃)
 ///
@@ -199,6 +202,18 @@ class _GamePlayScreenState extends State<GamePlayScreen>
           '${event.skillName} activated!',
           CombatLogType.buff,
         ),
+      CombatEventType.dotTick => (
+          '${event.skillName} ticks for ${event.damage} damage',
+          CombatLogType.dotTick,
+        ),
+      CombatEventType.playerPotion => (
+          '${event.skillName}: +${event.healAmount} ${event.targetName}',
+          CombatLogType.potion,
+        ),
+      CombatEventType.potionDrop => (
+          'Dropped: ${event.skillName}',
+          CombatLogType.potionDrop,
+        ),
     };
   }
 
@@ -534,6 +549,15 @@ class _GamePlayScreenState extends State<GamePlayScreen>
           // Phase 8: 스킬 (Skills with cooldown glow)
           _buildSectionHeader('Skills'),
           Expanded(flex: 2, child: SkillPanel(skillSystem: state.skillSystem)),
+
+          // 활성 버프 (Active Buffs)
+          _buildSectionHeader('Buffs'),
+          Expanded(
+            child: ActiveBuffPanel(
+              activeBuffs: state.skillSystem.activeBuffs,
+              currentMs: state.skillSystem.elapsedMs,
+            ),
+          ),
         ],
       ),
     );
@@ -549,12 +573,25 @@ class _GamePlayScreenState extends State<GamePlayScreen>
         children: [
           _buildPanelHeader(l10n.equipment),
 
-          // Equipment 목록
-          Expanded(flex: 2, child: _buildEquipmentList(state)),
+          // Equipment 목록 (확장 가능 스탯 패널)
+          Expanded(
+            flex: 2,
+            child: EquipmentStatsPanel(equipment: state.equipment),
+          ),
 
           // Inventory
           _buildPanelHeader(l10n.inventory),
-          Expanded(flex: 2, child: _buildInventoryList(state)),
+          Expanded(child: _buildInventoryList(state)),
+
+          // Potions (물약 인벤토리)
+          _buildSectionHeader('Potions'),
+          Expanded(
+            child: PotionInventoryPanel(
+              inventory: state.potionInventory,
+              usedInBattle:
+                  state.progress.currentCombat?.usedPotionTypes ?? const {},
+            ),
+          ),
 
           // Encumbrance 바
           _buildSectionHeader(l10n.encumbrance),
@@ -729,58 +766,6 @@ class _GamePlayScreenState extends State<GamePlayScreen>
     );
   }
 
-  Widget _buildEquipmentList(GameState state) {
-    // 원본 Main.dfm Equips ListView - 11개 슬롯
-    // (슬롯 레이블, 장비 이름, 슬롯 인덱스) 튜플
-    final l10n = L10n.of(context);
-    final equipment = [
-      (l10n.equipWeapon, state.equipment.weapon, 0),
-      (l10n.equipShield, state.equipment.shield, 1),
-      (l10n.equipHelm, state.equipment.helm, 2),
-      (l10n.equipHauberk, state.equipment.hauberk, 3),
-      (l10n.equipBrassairts, state.equipment.brassairts, 4),
-      (l10n.equipVambraces, state.equipment.vambraces, 5),
-      (l10n.equipGauntlets, state.equipment.gauntlets, 6),
-      (l10n.equipGambeson, state.equipment.gambeson, 7),
-      (l10n.equipCuisses, state.equipment.cuisses, 8),
-      (l10n.equipGreaves, state.equipment.greaves, 9),
-      (l10n.equipSollerets, state.equipment.sollerets, 10),
-    ];
-
-    return ListView.builder(
-      itemCount: equipment.length,
-      padding: const EdgeInsets.symmetric(horizontal: 8),
-      itemBuilder: (context, index) {
-        final equip = equipment[index];
-        // 장비 이름 번역 (슬롯 인덱스 사용)
-        final translatedName = equip.$2.isNotEmpty
-            ? GameDataL10n.translateEquipString(context, equip.$2, equip.$3)
-            : '-';
-        return Padding(
-          padding: const EdgeInsets.symmetric(vertical: 2),
-          child: Row(
-            children: [
-              SizedBox(
-                width: 60,
-                child: Text(equip.$1, style: const TextStyle(fontSize: 11)),
-              ),
-              Expanded(
-                child: Text(
-                  translatedName,
-                  style: const TextStyle(
-                    fontSize: 11,
-                    fontWeight: FontWeight.bold,
-                  ),
-                  overflow: TextOverflow.ellipsis,
-                ),
-              ),
-            ],
-          ),
-        );
-      },
-    );
-  }
-
   Widget _buildInventoryList(GameState state) {
     final l10n = L10n.of(context);
     if (state.inventory.items.isEmpty) {