refactor(live_chat): 调整结束直播消息处理逻辑

- 将 _handleEndLiveMessage 方法改为公共方法 handleEndLiveMessage
- 在 RTCManager 中添加对主播离开频道的处理
- 当远端用户为主播且频道ID存在时自动离开频道
- 集成 LiveChatMessageService 处理结束直播消息
- 添加对 OverlayController 的检查和关闭逻辑

lib/rtc/rtc_manager.dart

@@ -9,6 +9,7 @@ import 'package:get/get.dart';
 import '../controller/discover/room_controller.dart';
 import '../controller/message/call_controller.dart';
 import '../pages/discover/live_room_page.dart';
+import '../service/live_chat_message_service.dart';
 
 enum RTCType {
   call, // 通话（语音/视频通话）
@@ -208,6 +209,11 @@ class RTCManager {
                   channelId != null &&
                   channelId.isNotEmpty) {
                 final roomController = Get.find<RoomController>();
+                if(remoteUid == roomController.rtcChannelDetail.value?.anchorInfo?.uid){
+                  await roomController.leaveChannel();
+                  // 调用 LiveChatMessageService 处理结束直播消息
+                  LiveChatMessageService.instance.handleEndLiveMessage();
+                }
                 await roomController.fetchRtcChannelDetail(channelId);
                 }
               }

lib/service/live_chat_message_service.dart

@@ -72,7 +72,7 @@ class LiveChatMessageService {
       if (messageData['type'] == 'end_live') {
         RoomController controller = Get.find<RoomController>();
         await controller.leaveChannel();
-        _handleEndLiveMessage();
+        handleEndLiveMessage();
         return;
       }
       
@@ -119,7 +119,7 @@ class LiveChatMessageService {
   }
 
   /// 处理结束直播消息
-  void _handleEndLiveMessage() {
+  void handleEndLiveMessage() {
     try {
       // 检查 overlay 是否显示，如果显示则关闭
       if (Get.isRegistered<OverlayController>()) {