feat(子弹系统): 添加SPRINT运动类型并处理碰撞逻辑

为子弹系统新增SPRINT运动类型，并在Parrier子弹中处理其碰撞逻辑。当SPRINT类型子弹碰撞时，会销毁子弹并使发射者速度反向衰减。

scripts/Contents/Bullets/Parrier.gd

@@ -54,6 +54,9 @@ func hitBullet(bullet: BulletBase): # 当前子弹与其他子弹相撞
 					bullet.tryDestroy()
 			elif bullet.motionType == BulletBase.MotionType.SWING:
 				bullet.hitbox.disabled = true
+			elif bullet.motionType == BulletBase.MotionType.SPRINT:
+				bullet.tryDestroy()
+				bullet.launcher.velocity *= -0.1
 			elif bullet.motionType == BulletBase.MotionType.SUMMON || bullet.motionType == BulletBase.MotionType.MAGIC:
 				launcher.storeEnergy(sqrt(bullet.baseDamage))
 			var cycler = launcher.getOrCreateCycleTimer("parry", 2000, 100)

scripts/Statemachine/BulletBase.gd

@@ -2,10 +2,11 @@ extends Area2D
 class_name BulletBase
 
 enum MotionType {
-	SWING,
+	SWING, # 挥舞（近战攻击）
-	PROJECTILE,
+	PROJECTILE, # 射弹
-	MAGIC,
+	MAGIC, # 魔法
-	SUMMON
+	SUMMON, # 召唤
+	SPRINT, # 冲撞
 }
 
 @export var displayName: String = "未知子弹"