feat(子弹系统): 重构伤害计算并添加音效

将子弹的伤害属性从`damage`重命名为`baseDamage`，并引入`damageMultipliers`数组支持多段伤害
为火山武器添加三段攻击音效并调整伤害倍率
更新相关武器和子弹脚本以适配新的伤害系统

scripts/Contents/Weapons/BigLaser.gd

@@ -11,5 +11,5 @@ func attack(entity: EntityBase):
 	for bullet in BulletBase.generate(ComponentManager.getBullet("BigLaser"), entity, weaponPos, (get_global_mouse_position() - weaponPos).angle()):
 		var bigLaser: BigLaser = bullet
 		bigLaser.dotTime = readStore("time") * 1000
-		bigLaser.damage = readStore("atk")
+		bigLaser.baseDamage = readStore("atk")
 	return true