feat: 플레이어 다운 및 넉백 피격 반응 추가

- HitReactionController로 다운과 넉백 전용 로직을 분리
- 다운 시작, 루프, 회복 애니메이션과 DownEffect를 연결
- 행동 상태와 스킬 취소가 피격 반응과 연동되도록 정리
- 자동 검증 러너에 다운 및 넉백 검증을 추가

Assets/_Game/Scripts/Skills/Effects/DownEffect.cs

@@ -0,0 +1,42 @@
+using UnityEngine;
+
+using Colosseum.Player;
+
+namespace Colosseum.Skills.Effects
+{
+    /// <summary>
+    /// 대상에게 다운 상태를 적용하는 스킬 효과입니다.
+    /// </summary>
+    [CreateAssetMenu(fileName = "DownEffect", menuName = "Colosseum/Skills/Effects/Down")]
+    public class DownEffect : SkillEffect
+    {
+        [Header("Settings")]
+        [Tooltip("다운 지속 시간")]
+        [Min(0f)] [SerializeField] private float duration = 1f;
+
+        /// <summary>
+        /// 다운 지속 시간
+        /// </summary>
+        public float Duration => duration;
+
+        /// <summary>
+        /// 다운 효과를 적용합니다.
+        /// </summary>
+        protected override void ApplyEffect(GameObject source, GameObject target)
+        {
+            if (target == null)
+            {
+                Debug.LogWarning("[DownEffect] Target is null.");
+                return;
+            }
+
+            if (!target.TryGetComponent(out HitReactionController hitReactionController))
+            {
+                Debug.LogWarning($"[DownEffect] HitReactionController not found on target: {target.name}");
+                return;
+            }
+
+            hitReactionController.ApplyDown(duration);
+        }
+    }
+}

Assets/_Game/Scripts/Skills/Effects/DownEffect.cs.meta

@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 41c96b54a96cdb84c9bda774775b0a1a

Assets/_Game/Scripts/Skills/Effects/KnockbackEffect.cs

@@ -1,5 +1,7 @@
 using UnityEngine;
 
+using Colosseum.Player;
+
 namespace Colosseum.Skills.Effects
 {
     /// <summary>
@@ -11,6 +13,7 @@ namespace Colosseum.Skills.Effects
         [Header("Knockback Settings")]
         [Min(0f)] [SerializeField] private float force = 5f;
         [SerializeField] private float upwardForce = 2f;
+        [Min(0.05f)] [SerializeField] private float duration = 0.2f;
 
         protected override void ApplyEffect(GameObject caster, GameObject target)
         {
@@ -18,13 +21,23 @@ namespace Colosseum.Skills.Effects
 
             Vector3 direction = target.transform.position - caster.transform.position;
             direction.y = 0f;
-            direction.Normalize();
+            if (direction.sqrMagnitude <= 0.0001f)
+                direction = caster.transform.forward;
+            else
+                direction.Normalize();
 
-            Vector3 knockback = direction * force + Vector3.up * upwardForce;
+            Vector3 knockbackVelocity = direction * force + Vector3.up * upwardForce;
 
-            // TODO: 실제 물리 시스템 연동
-            // if (target.TryGetComponent<Rigidbody>(out var rb))
-            //     rb.AddForce(knockback, ForceMode.Impulse);
+            if (target.TryGetComponent<HitReactionController>(out var hitReactionController))
+            {
+                hitReactionController.ApplyKnockback(knockbackVelocity, duration);
+                return;
+            }
+
+            if (target.TryGetComponent<PlayerMovement>(out var playerMovement))
+            {
+                playerMovement.ApplyForcedMovement(knockbackVelocity, duration);
+            }
         }
     }
 }

Assets/_Game/Scripts/Skills/SkillController.cs

@@ -4,6 +4,19 @@ using Unity.Netcode;
 
 namespace Colosseum.Skills
 {
+    /// <summary>
+    /// 스킬 강제 취소 이유
+    /// </summary>
+    public enum SkillCancelReason
+    {
+        None,
+        Manual,
+        Death,
+        Stun,
+        HitReaction,
+        Respawn,
+    }
+
     /// <summary>
     /// 스킬 실행을 관리하는 컴포넌트.
     /// 애니메이션 이벤트 기반으로 효과가 발동됩니다.
@@ -31,6 +44,12 @@ namespace Colosseum.Skills
         [Tooltip("범위 표시 지속 시간")]
         [Min(0.1f)] [SerializeField] private float debugDrawDuration = 1f;
 
+        [Header("디버그")]
+        [Tooltip("마지막으로 강제 취소된 스킬 이름")]
+        [SerializeField] private string lastCancelledSkillName = string.Empty;
+        [Tooltip("마지막 강제 취소 이유")]
+        [SerializeField] private SkillCancelReason lastCancelReason = SkillCancelReason.None;
+
         // 현재 실행 중인 스킬
         private SkillData currentSkill;
         private bool skillEndRequested;      // OnSkillEnd 이벤트 호출 여부
@@ -47,9 +66,14 @@ namespace Colosseum.Skills
         public bool IgnoreRootMotionY => currentSkill != null && currentSkill.IgnoreRootMotionY;
         public SkillData CurrentSkill => currentSkill;
         public Animator Animator => animator;
+        public SkillCancelReason LastCancelReason => lastCancelReason;
+        public string LastCancelledSkillName => lastCancelledSkillName;
 
         private void Awake()
         {
+            lastCancelledSkillName = string.Empty;
+            lastCancelReason = SkillCancelReason.None;
+
             if (animator == null)
             {
                 animator = GetComponentInChildren<Animator>();
@@ -135,6 +159,7 @@ namespace Colosseum.Skills
             currentSkill = skill;
             skillEndRequested = false;
             waitingForEndAnimation = false;
+            lastCancelReason = SkillCancelReason.None;
 
             if (debugMode) Debug.Log($"[Skill] Cast: {skill.SkillName}");
 
@@ -339,16 +364,24 @@ namespace Colosseum.Skills
             if (debugMode) Debug.Log($"[Skill] End requested: {currentSkill.SkillName} (will complete after animation)");
         }
 
-        public void CancelSkill()
+        /// <summary>
+        /// 현재 스킬을 강제 취소합니다.
+        /// </summary>
+        public bool CancelSkill(SkillCancelReason reason = SkillCancelReason.Manual)
         {
-            if (currentSkill != null)
-            {
-                if (debugMode) Debug.Log($"Skill cancelled: {currentSkill.SkillName}");
-                RestoreBaseController();
-                currentSkill = null;
-                skillEndRequested = false;
-                waitingForEndAnimation = false;
-            }
+            if (currentSkill == null)
+                return false;
+
+            lastCancelledSkillName = currentSkill.SkillName;
+            lastCancelReason = reason;
+
+            Debug.Log($"[Skill] Cancelled: {currentSkill.SkillName} / reason={reason}");
+
+            RestoreBaseController();
+            currentSkill = null;
+            skillEndRequested = false;
+            waitingForEndAnimation = false;
+            return true;
         }
 
         public bool IsOnCooldown(SkillData skill)