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/infrastructure/pagination/index.ts

@@ -19,6 +19,16 @@ export type {
   FetchPageFunction,
 } from './types';
 
+// 导出游标分页相关类型
+export type {
+  CursorDirection,
+  CursorPaginationConfig,
+  CursorPaginationState,
+  CursorPaginationActions,
+  UseCursorPaginationReturn,
+  CursorFetchFunction,
+} from './types';
+
 // 导出工具函数和常量
 export {
   DEFAULT_PAGINATION_CONFIG,

src/infrastructure/pagination/types.ts

@@ -180,3 +180,79 @@ export function createPageCache<T>(
 export function isCacheExpired<T>(cache: PageCache<T>, ttl: number): boolean {
   return Date.now() - cache.cachedAt > ttl;
 }
+
+// ==================== 游标分页相关类型 ====================
+
+/**
+ * 游标分页方向
+ */
+export type CursorDirection = 'forward' | 'backward';
+
+/**
+ * 游标分页配置
+ */
+export interface CursorPaginationConfig {
+  /** 每页数量 */
+  pageSize: number;
+  /** 是否启用双向分页 */
+  bidirectional?: boolean;
+}
+
+/**
+ * 游标分页状态
+ */
+export interface CursorPaginationState<T> {
+  /** 数据项列表 */
+  items: T[];
+  /** 下一页游标 */
+  nextCursor: string | null;
+  /** 上一页游标 */
+  prevCursor: string | null;
+  /** 是否有更多数据 */
+  hasMore: boolean;
+  /** 是否正在加载 */
+  isLoading: boolean;
+  /** 是否正在刷新 */
+  isRefreshing: boolean;
+  /** 错误信息 */
+  error: string | null;
+  /** 是否为首次加载 */
+  isFirstLoad: boolean;
+}
+
+/**
+ * 游标分页操作
+ */
+export interface CursorPaginationActions<T> {
+  /** 加载更多（下一页） */
+  loadMore: () => Promise<void>;
+  /** 加载上一页（双向分页） */
+  loadPrevious: () => Promise<void>;
+  /** 刷新数据（重新从第一页加载） */
+  refresh: () => Promise<void>;
+  /** 重置状态 */
+  reset: () => void;
+  /** 设置数据（用于外部数据注入） */
+  setItems: (items: T[], nextCursor: string | null, prevCursor: string | null, hasMore: boolean) => void;
+}
+
+/**
+ * 游标分页 Hook 返回值
+ */
+export interface UseCursorPaginationReturn<T> extends CursorPaginationState<T>, CursorPaginationActions<T> {}
+
+/**
+ * 游标分页数据获取函数
+ */
+export type CursorFetchFunction<T, P = void> = (params: {
+  cursor?: string;
+  direction: CursorDirection;
+  pageSize: number;
+  /** 额外参数 */
+  extraParams?: P;
+}) => Promise<{
+  items: T[];
+  next_cursor: string | null;
+  prev_cursor: string | null;
+  has_more: boolean;
+}>;