Completion feed

To pull every tender that was completed recently — the typical ERP write-back trigger — pass completed_since (an ISO-8601 instant):

This returns only tenders with completed_at >= completed_since, ordered by completed_at ascending, and paginates with the same opaque cursor. Keep completed_since present on every page of the feed (its value is ignored once a cursor is supplied). Because completed_at is refreshed on every completion, a re-exported tender reappears in the feed — combine this with the tender.completed webhook for a robust push-plus-reconcile integration.

Note. /tenders reflects the request's current state: it returns one row per tender, not one row per historical export event. A re-exported tender reappears in the feed (via a refreshed completed_at) rather than accumulating separate rows.