refactor(ui): 물약 글로벌 쿨타임 적용 UI 정리

- usedPotionTypes/usedInBattle 파라미터 제거
- 전투당 타입별 제한 → 시간 기반 쿨타임 전환
- PotionInventoryPanel 불투명도 로직 제거

lib/src/core/engine/combat_tick_service.dart

@@ -7,6 +7,7 @@ import 'package:asciineverdie/src/core/model/combat_state.dart';
 import 'package:asciineverdie/src/core/model/combat_stats.dart';
 import 'package:asciineverdie/src/core/model/game_state.dart';
 import 'package:asciineverdie/src/core/model/monster_combat_stats.dart';
+import 'package:asciineverdie/src/core/model/potion.dart';
 import 'package:asciineverdie/src/core/model/skill.dart';
 import 'package:asciineverdie/src/core/util/deterministic_random.dart';