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/States/JumpState.cs

@@ -52,9 +52,20 @@ namespace BaseGames.Player.States
                 return;
             }
 
+            // ── 下冲刺（下 + 冲刺 → 向下冲刺，优先于普通冲刺）──────────────────────
+            // 按住下方向 + 冲刺键，且已解锁 DownDash 能力、空中冲刺次数未耗尽
+            var dashState = Owner.GetState<DashState>();
+            if (dashState != null && dashState.CanDashMidAir
+                && Input.MoveInput.y < -0.5f
+                && Stats != null && Stats.HasAbility(AbilityType.DownDash)
+                && Buffer.ConsumeDash())
+            {
+                _owner.TransitionTo(_owner.GetState<DownDashState>());
+                return;
+            }
+
             // 冲刺（地面/空中统一使用 DashState，空中限一次，优先于二段跳：冲刺可保存二段跳机会）
             // 先确认能力与冷却均满足，再消耗缓冲，避免无操作时静默吃掉输入
-            var dashState = Owner.GetState<DashState>();
             if (dashState != null && dashState.CanDashMidAir
                 && Stats != null && Stats.HasAbility(AbilityType.Dash)
                 && Buffer.ConsumeDash())