chore: 清除最后5处硬编码qq引用（注释+配置白名单）

backend/platform-bridge/internal/handler/config_handler.go

@@ -9,7 +9,7 @@ import (
 )
 
 var validPlatformTypes = map[string]bool{
-	"qq": true, "telegram": true, "webhook": true,
+	"obv11": true, "telegram": true, "webhook": true,
 	"wechat": true, "feishu": true, "discord": true,
 }