feat: 平台配置唯一ID — PlatformConfig.ID + adapter全链路传播

- PlatformConfig 新增 ID 字段 (8字节hex，创建时自动生成)
- QQ adapter 新增 configID + ConfigID() 访问器
- ChannelInfo 新增 AdapterID + AdapterName
- createSingleAdapter 接受 configID 参数
- 同一个平台类型的多个配置实例通过 ID 唯一区分

Co-Authored-By: Claude <noreply@anthropic.com>

backend/platform-bridge/internal/adapter/qq/adapter.go

@@ -26,6 +26,7 @@ var upgrader = websocket.Upgrader{
 //   - "server" (正向 WS): adapter starts a WS server, NapCat connects as client.
 //   - "client" (反向 WS): adapter connects to NapCat's WS server as a client.
 type Adapter struct {
+	configID       string // immutable unique ID from PlatformConfig
 	configName     string // instance name, e.g. "qq-home"
 	mode           string // "client" or "server"
 	port           string
@@ -46,11 +47,12 @@ type Adapter struct {
 	respMu           sync.Mutex
 }
 
-func NewAdapter(configName, mode, port, accessToken, remoteURL string, sendIntervalMs int) *Adapter {
+func NewAdapter(configID, configName, mode, port, accessToken, remoteURL string, sendIntervalMs int) *Adapter {
 	if mode == "" {
 		mode = "server"
 	}
 	return &Adapter{
+		configID:         configID,
 		configName:       configName,
 		mode:             mode,
 		port:             port,
@@ -63,6 +65,7 @@ func NewAdapter(configName, mode, port, accessToken, remoteURL string, sendInter
 }
 
 func (a *Adapter) PlatformName() string   { return "qq" }
+func (a *Adapter) ConfigID() string      { return a.configID }
 func (a *Adapter) ConfigName() string    { return a.configName }
 func (a *Adapter) SendIntervalMs() int   { return a.sendIntervalMs }
 func (a *Adapter) SelfID() string        { return a.selfID }