feat(子弹系统): 完善乾坤剑和格挡子弹的逻辑

添加乾坤剑的追踪和攻击逻辑，包括命中目标后的效果
调整格挡子弹的伤害值和生成气的逻辑
优化子弹动画和碰撞箱设置
为乾坤剑添加基础伤害和穿透属性

scripts/Contents/Bullets/QKSword.gd

@@ -2,9 +2,20 @@ extends BulletBase
 class_name QKSwordBullet
 
 var tracer: EntityBase
+var attackedTracer: bool = false
 
 func ai():
-	if is_instance_valid(tracer):
-		look_at(tracer.position)
+	if is_instance_valid(tracer) && !attackedTracer:
+		look_at(tracer.getTrackingAnchor())
 	if timeLived() > 1000:
-		PresetBulletAI.forward(self , rotation)
+		PresetBulletAI.forward(self , rotation) # 前进
+		hitbox.disabled = false
+	else:
+		hitbox.disabled = true
+func succeedToHit(_dmg: float, entity: EntityBase):
+	if entity == tracer:
+		attackedTracer = true # 只需要命中一次目标就不需要继续前进了
+	EffectController.create(
+		ComponentManager.getEffect("CatBoom"),
+		entity.texture.global_position
+	).shot()