feat(ui): add emoji picker with FlatList virtualization and improve input components

- Add full emoji picker with virtualized FlatList to CreatePostScreen and PostDetailScreen
- Add autoExpand prop to PostMentionInput for XHS-style content area
- Improve mention item styling with @ icon and hint text
- Fix HomeScreen tab switching race condition with requestAnimationFrame
- Fix PostRepository pagination to prefer cursor over page parameter
- Fix user store imports to use explicit UserManager path
- Refactor useCurrentUser hook to use sessionStore directly

src/data/repositories/PostRepository.ts

@@ -241,11 +241,12 @@ export class PostRepository implements IPostRepository {
     try {
       const queryParams: Record<string, any> = {};
 
-      if (params?.page !== undefined) queryParams.page = params.page;
       if (params?.pageSize) queryParams.page_size = params.pageSize;
-      // 支持 cursor 参数：空字符串也传递，用于启动 cursor 模式
+      // cursor 与 page 互斥：cursor 存在（含空字符串）时走游标分页，否则走页码分页
       if (params?.cursor !== undefined && params?.cursor !== null) {
         queryParams.cursor = params.cursor;
+      } else if (params?.page !== undefined) {
+        queryParams.page = params.page;
       }
       if (params?.post_type) queryParams.tab = params.post_type;
       if (params?.channelId) queryParams.channel_id = params.channelId;