[UI] 스킬 퀵슬롯 UI 구현

- SkillSlotUI: 개별 슬롯 (아이콘, 쿨다운 오버레이, 텍스트)
- SkillQuickSlotUI: 6개 슬롯 관리 및 PlayerSkillInput 연동
- Animator 제어 문제 해결: 수동 SetActive로 쿨다운 표시
- UI_Bar에 PlayerHUD, StatBar 컴포넌트 추가

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Assets/Skills/DodgeRoll_Sword.asset

@@ -14,11 +14,11 @@ MonoBehaviour:
   m_EditorClassIdentifier: Colosseum.Game::Colosseum.Skills.SkillData
   skillName: "\uAD6C\uB974\uAE30"
   description: 
-  icon: {fileID: 0}
+  icon: {fileID: 21300000, guid: 2b3889a2bb9beb444adf6734821e1c02, type: 3}
   skillClip: {fileID: -14460799136228694, guid: d6d51384d6dd17a419c1d8e2a1c0c875, type: 3}
   endClip: {fileID: 0}
   useRootMotion: 1
   ignoreRootMotionY: 1
-  cooldown: 1
+  cooldown: 10
   manaCost: 0
   effects: []