Shortlist Refresh Tick

Rebuild shortlists that got thumbed down, and say so (Epic 5.4).

For each lead whose card feedback is newer than their last refresh: drop the rejected cards, keep the liked ones, pull replacements through list_matching_bench with whatever seniority shift the reason chips authorise, and email "we reworked your shortlist".

The email only goes out when cards actually changed. A refresh that swaps nothing sends nothing — "we refreshed your shortlist" over an identical slate is the fabricated-progress cousin of a countdown timer, and this wave bans those.

Idempotent: leads.shortlist_refreshed_at is the watermark and is stamped on every path that examined the feedback, including the no-ops, so a re-run finds nothing to redo and never re-emails.

External GitHub Actions cron (shortlist-lifecycle-cron.yml), NOT in-process APScheduler — interval jobs starve on ephemeral Railway replicas (enrollment incident 2026-08-18).