-- #182. The season release deck cannot tell a queued pack sweep from one
-- that ran and found nothing, so it blames backoff for both. Only the season
-- knows when its own pack search last completed: episodes' `last_searched_at`
-- moves for reasons that have nothing to do with the pack lane, and a season
-- on the per-episode lane never touches the pack search at all.
ALTER TABLE seasons ADD COLUMN last_pack_search_at TEXT;