refactor(MessageManager): enhance conversation list handling and integrate local source fallback

- Update MessageManager to support both remote and local conversation list sources, improving data retrieval and offline capabilities.
- Refactor hooks and components to utilize the new MessageManager structure, ensuring seamless integration of cursor pagination and local caching.
- Introduce new types and methods for better management of conversation data and loading states.
- Modify MessageListScreen to leverage the updated hooks for fetching conversations, enhancing user experience with improved loading and pagination handling.

src/stores/messageManagerHooks.ts

@@ -16,17 +16,20 @@ interface UseConversationsReturn {
   conversations: ConversationResponse[];
   isLoading: boolean;
   refresh: () => Promise<void>;
+  loadMore: () => Promise<void>;
+  hasMore: boolean;
 }
 
 /**
- * 获取会话列表
- * 用于MessageListScreen等需要显示会话列表的组件
+ * 获取会话列表（仅消费 MessageManager；网络游标与 SQLite 回退均在 Manager 内完成，调用方无感）
+ * 用于 MessageListScreen 等需要显示会话列表的组件
  */
 export function useConversations(): UseConversationsReturn {
   const [conversations, setConversations] = useState<ConversationResponse[]>(
     () => messageManager.getConversations()
   );
   const [isLoading, setIsLoading] = useState(() => messageManager.isLoading());
+  const [hasMore, setHasMore] = useState(() => messageManager.canLoadMoreConversations());
 
   useEffect(() => {
     // 订阅MessageManager的事件
@@ -34,6 +37,10 @@ export function useConversations(): UseConversationsReturn {
       switch (event.type) {
         case 'conversations_updated':
           setConversations(messageManager.getConversations());
+          setHasMore(messageManager.canLoadMoreConversations());
+          break;
+        case 'conversations_loading':
+          setIsLoading(!!event.payload?.loading);
           break;
         case 'connection_changed':
           // 连接状态变化时可能需要刷新
@@ -60,15 +67,19 @@ export function useConversations(): UseConversationsReturn {
   }, []);
 
   const refresh = useCallback(async () => {
-    setIsLoading(true);
     await messageManager.fetchConversations(true);
-    setIsLoading(false);
+  }, []);
+
+  const loadMore = useCallback(async () => {
+    await messageManager.loadMoreConversations();
   }, []);
 
   return {
     conversations,
     isLoading,
     refresh,
+    loadMore,
+    hasMore,
   };
 }
 
@@ -672,6 +683,8 @@ interface UseMessageListReturn {
   conversations: ConversationResponse[];
   isLoading: boolean;
   refresh: () => Promise<void>;
+  loadMore: () => Promise<void>;
+  hasMore: boolean;
   totalUnreadCount: number;
   systemUnreadCount: number;
   markAllAsRead: () => Promise<void>;
@@ -679,7 +692,7 @@ interface UseMessageListReturn {
 }
 
 export function useMessageList(): UseMessageListReturn {
-  const { conversations, isLoading, refresh } = useConversations();
+  const { conversations, isLoading, refresh, loadMore, hasMore } = useConversations();
   const { totalUnreadCount, systemUnreadCount } = useUnreadCount();
   const { markAllAsRead, isMarking } = useMarkAsRead(null);
 
@@ -687,6 +700,8 @@ export function useMessageList(): UseMessageListReturn {
     conversations,
     isLoading,
     refresh,
+    loadMore,
+    hasMore,
     totalUnreadCount,
     systemUnreadCount,
     markAllAsRead,