chore: 清除最后5处硬编码qq引用（注释+配置白名单）

backend/platform-bridge/internal/config/store.go

@@ -14,7 +14,7 @@ import (
 type PlatformConfig struct {
 	ID        string            `json:"id"`        // immutable unique ID, generated at creation
 	Name      string            `json:"name"`      // config key, e.g. "qq-main", "qq-work"
-	Platform  string            `json:"platform"`  // base platform type: "qq", "telegram", etc.
+	Platform  string            `json:"platform"`  // base platform type: "obv11", "telegram", etc.
 	Enabled   bool              `json:"enabled"`
 	Label     string            `json:"label"`
 	Fields    map[string]string `json:"fields"`