## AudioBusID — AudioBus 索引常量（Autoload: AudioBusID）
## 与 AudioServer 路由层（architecture_design.md ADR-A3）对应。
## 禁止在 SettingsManager 等处使用字符串查 Bus（跨切片约束）。
extends Node

const MASTER:      int = 0
const BGM:         int = 1
const BGM_BASE:    int = 2
const BGM_LAYER:   int = 3
const SFX:         int = 4
const SFX_COMBAT:  int = 5
const SFX_SPATIAL: int = 6
const UI:          int = 7
const AMBIENCE:    int = 8
const VOICE:       int = 9