chore: Assets 디렉토리 구조 정리 및 네이밍 컨벤션 적용

- Assets/_Game/ 하위로 게임 에셋 통합
- External/ 패키지 벤더별 분류 (Synty, Animations, UI)
- 에셋 네이밍 컨벤션 확립 및 적용
  (Data_Skill_, Data_SkillEffect_, Prefab_, Anim_, Model_, BT_ 등)
- pre-commit hook으로 네이밍 컨벤션 자동 검사 추가
- RESTRUCTURE_CHECKLIST.md 작성

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

Assets/External/UI/InterfaceFantasyWarriorHUD/Samples/Scripts/SampleURL.cs

@@ -0,0 +1,27 @@
+// Copyright (c) 2024 Synty Studios Limited. All rights reserved.
+//
+// Use of this software is subject to the terms and conditions of the End User Licence Agreement (EULA) 
+// of the store at which you purchased this asset. 
+//
+// Synty assets are available at:
+// https://www.syntystore.com
+// https://assetstore.unity.com/publishers/5217
+// https://www.fab.com/sellers/Synty%20Studios
+//
+// Sample scripts are included only as examples and are not intended as production-ready.
+
+using UnityEngine;
+
+namespace Synty.Interface.FantasyWarriorHUD.Samples
+{
+    /// <summary>
+    ///     Opens a URL in the default browser.
+    /// </summary>
+    public class SampleURL : MonoBehaviour
+    {
+        public void OpenURL(string url)
+        {
+            Application.OpenURL(url);
+        }
+    }
+}