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
- Add pagination infrastructure with usePagination and usePaginationManager hooks
- Add connection state management hook for network status tracking
- Add media caching infrastructure with useMediaCache hook
- Add differential message synchronization infrastructure
- Export new hooks from central index file
- Remove backup file MainNavigator.tsx.bak
