The /history page fetched a fixed first 200 POs in one flat table with no
way to page further and no control over page size. Replace that with real
pagination:
- page.tsx: read page/perPage from searchParams; clamp perPage to 25/50/100
(default 25) and page to [1, totalPages] via a new shared resolvePagination
helper. Swap the fixed take:200 for skip/take + a count() for totals.
Replace the "first 200 results" notice with a footer ("Showing X-Y of N",
Prev/Next, page indicator) that preserves all filters. Export PDF/CSV links
stay on the full filtered set.
- history-filters.tsx: add a Per-page dropdown; changing it or any filter
resets to page 1 while preserving perPage in the URL.
- lib/pagination.ts: dependency-free clamp/skip/take helper, unit-tested.
Verified: type-check clean, 272 unit tests pass (9 new), skip/take windows
and clamping checked against the test DB.
Fixes#104
