Re-fetch ONE crawled page now, whatever tier it is in.

Not rate-limited: the work is a single conditional GET against a page the customer owns, which is less traffic than the browser tab they clicked it from. The whole-site button below is the one that needs a limit.

Two writes, and the order matters. next_check_at/recheck_reason are set FIRST and committed, so the intent is durable even if the enqueue fails — the page is then picked up by the next nightly tick instead of being silently forgotten. Enqueueing first and crashing before the commit would lose it.