feat(战斗系统): 添加内伤机制和爆炸类型子弹

为子弹系统添加新的爆炸类型(MotionType.EXPLOSION)
实现内伤机制，包括内伤子弹和相关逻辑
修改多个子弹场景以使用爆炸类型
调整格挡系统，增加内伤效果
更新武器描述和角色配置

scripts/Statemachine/BulletBase.gd

@@ -9,6 +9,7 @@ enum MotionType {
 	SPRINT, # 冲撞
 	BREATH, # 吐息
 	STAB, # 近战戳刺
+	EXPLOSION, # 爆炸
 }
 
 signal destroied(becauseMap: bool)

scripts/Statemachine/CycleTimer.gd

@@ -16,7 +16,7 @@ func getStateAngle(index: int):
 	return lifetime() / period * deg_to_rad(360) - deg_to_rad(360.0 * index / len(bullets))
 func forceFilter():
 	bullets = bullets.filter(is_instance_valid)
-func apply():
+func apply(where: Vector2):
 	forceFilter()
 	for index in len(bullets):
 		var bullet = bullets[index]
@@ -24,7 +24,7 @@ func apply():
 		var offset = Vector2.from_angle(newStateAngle)
 		bullet.cycleStateAngle = newStateAngle
 		offset.y *= 0.25
-		bullet.position = bullet.launcher.position + offset * distance
+		bullet.position = where + offset * distance
 		bullet.scale = Vector2.ONE * (1 + offset.y)
 func host(bullet: BulletBase):
 	bullets.append(bullet)

scripts/Statemachine/EntityBase.gd

@@ -214,7 +214,7 @@ func _physics_process(_delta: float) -> void:
 	trailParticle.emitting = trailing
 	for cycler in cycleTimers.values():
 		if cycler is CycleTimer:
-			cycler.apply()
+			cycler.apply(position)
 
 # 通用方法
 func impluse(force: Vector2):