feat(武器): 重做链式机枪并添加音效

重构链式机枪的子弹生成逻辑，降低散射衰减系数
添加射击音效资源及导入配置
调整武器属性描述和数值
移除测试用的调试代码

scripts/Contents/Weapons/ChainGun.gd

@@ -4,7 +4,7 @@ extends Weapon
 func update(to, origin, _entity):
 	origin["atk"] += 2 * to * soulLevel
 	origin["count"] = 1 * soulLevel
-	origin["split"] /= 1 + 0.05 * to * soulLevel
+	origin["split"] /= 1 + 0.005 * to * soulLevel
 	return origin
 func attack(entity: EntityBase):
 	for i in BulletBase.generate(ComponentManager.getBullet("ChainGun"), entity, entity.texture.global_position, (get_global_mouse_position() - entity.texture.global_position).angle()):
@@ -12,3 +12,4 @@ func attack(entity: EntityBase):
 			i.baseDamage = readStore("atk")
 			i.count = floor(readStore("count"))
 			i.splits = readStore("split")
+	return true