feat: 플레이어 다운/넉백 피격 반응 추가

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);
+            }
         }
     }
 }