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/PlayerStats.cs

@@ -257,12 +257,29 @@ namespace BaseGames.Player
         }
 
         // ── Spring ────────────────────────────────────────────────────────────
-        public bool UseSpring()
+
+        /// <summary>
+        /// 仅扣除灵泉充能（SpringState 进入前摇时调用）。
+        /// 回血需前摇结束后调用 <see cref="ApplySpringHeal"/>。
+        /// </summary>
+        public bool ConsumeSpringCharge()
         {
             if (CurrentSpringCharges <= 0) return false;
             CurrentSpringCharges--;
             _onSpringChargesChanged?.Raise(CurrentSpringCharges);
-            HealHP(_config.SpringHealAmount);
+            return true;
+        }
+
+        /// <summary>
+        /// 执行灵泉回血（SpringState 前摇动画结束时调用）。
+        /// </summary>
+        public void ApplySpringHeal() => HealHP(_config.SpringHealAmount);
+
+        /// <summary>扣除充能并立即回血（兼容旧调用路径）。</summary>
+        public bool UseSpring()
+        {
+            if (!ConsumeSpringCharge()) return false;
+            ApplySpringHeal();
             return true;
         }