#338: page N of the /banks/ directory. Before this the index listed the top 250 of ~4,400 active institutions with no next link, so the tail was unreachable by a reader OR a crawler even though every /bank/<cert> page already rendered.

page is typed str, not int, deliberately: an int path param makes FastAPI answer /banks/page/abc with a 422 validation body, which is a machine-readable error page under a public URL. A junk segment here is just a wrong URL, so it gets a plain 404 like every other bad path.

Page 1 301s to /banks/ — one canonical URL per page of results, never two. An out-of-range page 404s rather than rendering an empty table (soft-404).