Data Fetching and Caching Patterns

Data from a server is asynchronous, can go stale, can fail, and is often needed by more than one component at once — treating it like local useState leads to duplicated loading/error handling and components silently showing stale data. TanStack Query (formerly React Query) treats server data as a first-class cache with its own lifecycle. This project replaces a hand-rolled useEffect fetch with useQuery, adds mutations with optimistic updates, and handles pagination.