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/Conditions/IsInAttackRangeCondition.cs

@@ -0,0 +1,37 @@
+using System;
+using UnityEngine;
+using Unity.Behavior;
+using Unity.Properties;
+using Condition = Unity.Behavior.Condition;
+
+namespace Colosseum.AI.BehaviorActions.Conditions
+{
+    /// <summary>
+    /// 타겟이 공격 사거리 내에 있는지 확인합니다.
+    /// </summary>
+    [Serializable, GeneratePropertyBag]
+    [NodeDescription(name: "Is In Attack Range", story: "Is [Target] within [Range]", category: "Combat")]
+    public partial class IsInAttackRangeCondition : Condition
+    {
+        [SerializeReference]
+        public BlackboardVariable<GameObject> Target;
+        
+        [SerializeReference]
+        public BlackboardVariable<float> Range = new BlackboardVariable<float>(2f);
+
+        public override bool IsTrue()
+        {
+            if (Target.Value == null)
+            {
+                return false;
+            }
+
+            float distance = Vector3.Distance(
+                GameObject.transform.position,
+                Target.Value.transform.position
+            );
+
+            return distance <= Range.Value;
+        }
+    }
+}