refactor(stores): reorganize flat store files into modular directory structure

Migrate from flat file organization to modular directory structure under src/stores/:

- auth/: authStore, registerStore, verificationStore, sessionStore
- call/: callStore
- settings/: chatSettingsStore, themeStore
- ui/: homeTabBarVisibilityStore, homeTabPressStore
- utils/: routePayloadCache
- group/sources.ts, group/profileResolver.ts
- message/sources.ts
- post/sources.ts

Update all import paths across components and screens to use new module paths. Maintain backward compatibility through deprecated re-export files for gradual migration.

src/stores/message/index.ts

@@ -72,7 +72,7 @@ export {
   WSMessageHandler,
 } from './services';
 
-// ==================== Hooks 导出 ====================
+// ==================== Hooks 导出（便捷版，使用 messageManager 单例） ====================
 export {
   // 会话相关
   useConversations,
@@ -87,6 +87,7 @@ export {
   
   // 未读数相关
   useUnreadCount,
+  useTotalUnreadCount,
   useSystemUnreadCount,
   
   // 群聊相关
@@ -95,9 +96,21 @@ export {
   
   // 通用
   useMessageManager,
-  useConnectionStatus,
-  useIsInitialized,
+  useMessageListRefresh,
+  useChat,
+  useMessageList,
 } from './hooks';
 
+// ==================== 数据源导出 ====================
+export {
+  CONVERSATION_LIST_PAGE_SIZE,
+  type ConversationListPage,
+  type IConversationListPagedSource,
+  type RemoteConversationListSourceKind,
+  NetworkRemoteConversationListPagedSource,
+  SqliteConversationListPagedSource,
+  createRemoteConversationListSource,
+} from './sources';
+
 // ==================== 默认导出 ====================
 export { default } from './MessageManager';