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/Skills/Effects/HealEffect.cs

@@ -0,0 +1,49 @@
+using UnityEngine;
+
+using Colosseum.Stats;
+using Colosseum.Combat;
+
+namespace Colosseum.Skills.Effects
+{
+    /// <summary>
+    /// 치료 효과
+    /// </summary>
+    [CreateAssetMenu(fileName = "HealEffect", menuName = "Colosseum/Skills/Effects/Heal")]
+    public class HealEffect : SkillEffect
+    {
+        [Header("Heal Settings")]
+        [Min(0f)] [SerializeField] private float baseHeal = 10f;
+        [Tooltip("회복력 계수 (1.0 = 100%)")]
+        [Min(0f)] [SerializeField] private float healScaling = 1f;
+
+        protected override void ApplyEffect(GameObject caster, GameObject target)
+        {
+            if (target == null) return;
+
+            // 회복량 계산
+            float totalHeal = CalculateHeal(caster);
+
+            // 타겟에 회복 적용 (IDamageable 인터페이스 사용)
+            var damageable = target.GetComponent<IDamageable>();
+            if (damageable != null)
+            {
+                damageable.Heal(totalHeal);
+            }
+        }
+
+        /// <summary>
+        /// 시전자 스탯 기반 회복량 계산
+        /// 공식: baseHeal + (healPower * healScaling)
+        /// </summary>
+        private float CalculateHeal(GameObject caster)
+        {
+            var stats = caster.GetComponent<CharacterStats>();
+            if (stats == null)
+            {
+                return baseHeal;
+            }
+
+            return baseHeal + (stats.HealPower * healScaling);
+        }
+    }
+}