feat: Implement DownDash ability and related systems

- Added DownDash ability with cooldown and speed configuration.
- Introduced DownDashState to handle down dashing mechanics, including gravity manipulation and animation playback.
- Updated PlayerMovement to support DownDash functionality.
- Enhanced PlayerStats to manage spring charge consumption and healing.
- Modified PlayerCombat and WeaponHitBoxInstance to support new hit confirmation events.
- Updated AbilityType to include new form types for character abilities.
- Improved Gizmos for better visualization of enemy detection and attack ranges.
- Added feedback systems for form switching in PlayerFeedback and IFeedbackPlayer.
- Refactored combat and movement states to accommodate new abilities and ensure smooth transitions.

Assets/_Game/Scripts/Player/WeaponManager.cs

@@ -27,6 +27,9 @@ namespace BaseGames.Player
         // 护符注入的武器覆盖：Key = FormSO.formId，Value = 替换武器（架构 05 §7）
         private readonly Dictionary<string, WeaponSO> _overrides = new();
 
+        // 对象池：避免每次切换形态时 Instantiate/Destroy（Key = WeaponSO，Value = 已创建实例）
+        private readonly Dictionary<WeaponSO, WeaponHitBoxInstance> _hitBoxPool = new();
+
         private void Awake()
         {
             if (_formController != null && _formController.CurrentForm != null)
@@ -70,22 +73,33 @@ namespace BaseGames.Player
 
         private void SetDirectWeapon(WeaponSO weapon)
         {
-            var oldInstance = ActiveHitBoxInstance;
+            // 归还旧实例到池（SetActive(false) 会触发 HitBox.OnDisable → Deactivate，自动关闭 Collider2D）
+            ActiveHitBoxInstance?.gameObject.SetActive(false);
 
             ActiveWeapon         = weapon;
             ActiveHitBoxInstance = null;
 
             if (weapon?.hitBoxPrefab != null && _weaponSocket != null)
             {
-                var go = Instantiate(weapon.hitBoxPrefab, _weaponSocket);
-                ActiveHitBoxInstance = go.GetComponent<WeaponHitBoxInstance>();
+                if (!_hitBoxPool.TryGetValue(weapon, out var pooled) || pooled == null)
+                {
+                    var go = Instantiate(weapon.hitBoxPrefab, _weaponSocket);
+                    pooled = go.GetComponent<WeaponHitBoxInstance>();
+                    _hitBoxPool[weapon] = pooled;
+                }
+                pooled.gameObject.SetActive(true);
+                ActiveHitBoxInstance = pooled;
             }
 
-            // 先通知订阅者（使其有机会取消对旧实例的事件订阅），再销毁旧实例
+            // 通知订阅者（PlayerCombat 取消旧实例事件订阅，订阅新实例）
             OnWeaponChanged?.Invoke(weapon);
+        }
 
-            if (oldInstance != null)
-                Destroy(oldInstance.gameObject);
+        private void OnDestroy()
+        {
+            foreach (var inst in _hitBoxPool.Values)
+                if (inst != null) Destroy(inst.gameObject);
+            _hitBoxPool.Clear();
         }
 
         // ── 护符 Override API（由 WeaponOverrideEffect 调用，架构 05 §7）──────