feat(聊天会话更新): 优化聊天会话处理逻辑，简化未读消息清除和会话更新的代码结构，提高可读性和维护性。

Touchkebao/src/store/module/weChat/weChat.ts

@@ -150,22 +150,21 @@ export const useWeChatStore = create<WeChatState>()(
           params.wechatChatroomId = contract.id;
         }
 
-        clearUnreadCount(params).then(() => {
-          if (isExist) {
-            updateChatSession({
-              ...contract,
-              config: { unreadCount: 0 },
-            });
-          } else {
-            addChatSession(contract);
-          }
-          set({ currentContract: contract });
-          updateConfig({
-            id: contract.id,
-            config: { chat: true },
+        clearUnreadCount(params);
+        if (isExist) {
+          updateChatSession({
+            ...contract,
+            config: { unreadCount: 0 },
           });
-          state.loadChatMessages(true, 4704624000000);
+        } else {
+          addChatSession(contract);
+        }
+        set({ currentContract: contract });
+        updateConfig({
+          id: contract.id,
+          config: { chat: true },
         });
+        state.loadChatMessages(true, 4704624000000);
       },
 
       // ==================== 消息加载方法 ====================