feat(pagination): implement cursor-based pagination across the app

Add useCursorPagination hook and update multiple screens and services
to use cursor-based pagination for better performance and consistency.

- Add useCursorPagination hook with deduplication and caching support
- Add cursor pagination types to infrastructure layer
- Refactor HomeScreen, PostDetailScreen, SearchScreen for posts/comments
- Refactor GroupMembersScreen, JoinGroupScreen for groups/members
- Refactor MessageListScreen, NotificationsScreen for messages
- Update post, message, group, comment, notification services with cursor endpoints
- Add CursorPaginationRequest/Response DTOs
- Remove deprecated OPTIMIZATION_DESIGN.md documentation

src/services/postService.ts

@@ -5,6 +5,7 @@
 
 import { api, PaginatedData } from './api';
 import { Post, CreatePostInput } from '../types';
+import { CursorPaginationRequest, CursorPaginationResponse } from '../types/dto';
 
 // 帖子列表响应
 interface PostListResponse {
@@ -281,6 +282,92 @@ class PostService {
       return false;
     }
   }
+
+  // ==================== 游标分页方法 ====================
+
+  /**
+   * 获取帖子列表（游标分页）
+   * GET /api/v1/posts/cursor
+   * @param params 游标分页请求参数（包含 post_type 可选：recommend, follow, hot, latest）
+   */
+  async getPostsCursor(
+    params: CursorPaginationRequest = {}
+  ): Promise<CursorPaginationResponse<Post>> {
+    try {
+      const response = await api.get<CursorPaginationResponse<Post>>('/posts/cursor', {
+        params: {
+          cursor: params.cursor,
+          page_size: params.page_size,
+          post_type: params.post_type,
+        },
+      });
+      return response.data;
+    } catch (error) {
+      console.error('获取帖子列表失败:', error);
+      return {
+        items: [],
+        next_cursor: null,
+        prev_cursor: null,
+        has_more: false,
+      };
+    }
+  }
+
+  /**
+   * 搜索帖子（游标分页）
+   * GET /api/v1/posts/search/cursor
+   * @param query 搜索关键词
+   * @param params 游标分页请求参数
+   */
+  async searchPostsCursor(
+    query: string,
+    params: CursorPaginationRequest = {}
+  ): Promise<CursorPaginationResponse<Post>> {
+    try {
+      const response = await api.get<CursorPaginationResponse<Post>>('/posts/search/cursor', {
+        params: {
+          ...params,
+          keyword: query,
+        },
+      });
+      return response.data;
+    } catch (error) {
+      console.error('搜索帖子失败:', error);
+      return {
+        items: [],
+        next_cursor: null,
+        prev_cursor: null,
+        has_more: false,
+      };
+    }
+  }
+
+  /**
+   * 获取用户帖子列表（游标分页）
+   * GET /api/v1/users/:id/posts/cursor
+   * @param userId 用户ID
+   * @param params 游标分页请求参数
+   */
+  async getUserPostsCursor(
+    userId: string,
+    params: CursorPaginationRequest = {}
+  ): Promise<CursorPaginationResponse<Post>> {
+    try {
+      const response = await api.get<CursorPaginationResponse<Post>>(
+        `/users/${userId}/posts/cursor`,
+        { params }
+      );
+      return response.data;
+    } catch (error) {
+      console.error('获取用户帖子列表失败:', error);
+      return {
+        items: [],
+        next_cursor: null,
+        prev_cursor: null,
+        has_more: false,
+      };
+    }
+  }
 }
 
 // 导出帖子服务实例