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/_Game/Scripts/AI/BehaviorActions/Actions/StopMovementAction.cs

@@ -0,0 +1,24 @@
+using System;
+using Unity.Behavior;
+using UnityEngine;
+using Action = Unity.Behavior.Action;
+using Unity.Properties;
+
+[Serializable, GeneratePropertyBag]
+[NodeDescription(name: "StopMovement", story: "이동 정지", category: "Action", id: "1a0e2eb87421ed94502031790df56f37")]
+public partial class StopMovementAction : Action
+{
+
+    protected override Status OnStart()
+    {
+        UnityEngine.AI.NavMeshAgent agent = GameObject.GetComponent<UnityEngine.AI.NavMeshAgent>();
+        
+        if (agent != null)
+        {
+            agent.isStopped = true;
+        }
+
+        return Status.Success;
+    }
+}
+