Pagination components need to manage current page, total pages, items per page, and navigation between pages. Manually calculating next/previous and bounds is error‑prone.
PaginationManager manages page, pageSize, and totalItems. It computes
totalPages, hasNext, hasPrevious, and provides goToPage, next,
previous, first, last. Subscribers are notified on any change.
Pagination, DataTable, Carousel, ProductList, BlogArchive