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/FallState.cs

@@ -6,6 +6,7 @@ namespace BaseGames.Player.States
     /// 下落状态。
     /// - 郊狼跳：CoyoteTimer > 0 时按跳跃 → 一段跳（JumpState，使用 JumpForce）。
     /// - 空中跳跃：CoyoteTimer 耗尽后按跳跃且 AirJumpsLeft > 0 → JumpState（使用 DoubleJumpForce）。
+    /// - 下冲刺：HasAbility(DownDash) && 下方向 + 冲刺键 → DownDashState（优先于普通冲刺）。
     /// - 冲刺：HasAbility(Dash) && DashState.CanDashMidAir → DashState（地面与空中统一，空中限一次）。
     /// - 抓墙：贴墙时按下朝向墙壁的方向键 → WallSlideState。
     /// - 增强下落重力（FallGravityMult）确保下落快于上升，手感紧实。
@@ -53,9 +54,20 @@ 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）────────────────────────────
             // 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())