fix: 管理员群聊消息不再静默，始终正常处理

backend/platform-bridge/cmd/main.go

@@ -210,12 +210,6 @@ func main() {
 			fireSilent(namespace, nil, videoURLs, voiceURLs)
 			response = &bridge.UnifiedResponse{Messages: []bridge.ResponseMessage{{DisplayType: "silent"}}, Platform: msg.Platform}
 
-		case isAdmin && !isBotMentioned && shouldAdminBeSilent(msg, router):
-			msg.RouteType = "silent"
-			namespace := buildMemoryNamespace(msg.Platform, msg.ChannelType, msg.ChannelID)
-			fireSilent(namespace, imageURLs, videoURLs, voiceURLs)
-			response = &bridge.UnifiedResponse{Messages: []bridge.ResponseMessage{{DisplayType: "silent"}}, Platform: msg.Platform}
-
 		case isAdmin:
 			msg.RouteType = "normal"
 			response, routeErr = forwardToAICore(cfg, msg, "text", chatUserID, groupSessionID, imageURLs, videoURLs, voiceURLs, isAdmin)