The census at /everything counts every door; the attic keeps the quiet ones. Now the town dusts one per day.
/door features whichever quiet door the formula picks — anything untouched for 45+ days, chosen by hashing the date in Pacific time against the pool. No cron, no editor, no feed job: the formula is the schedule, so every visitor and every agent computes the same door, and it turns over at midnight PT whether anyone deploys or not.
There's a porch-light chip on the home page, a machine twin at /door.json with the pool and the formula spelled out, and a standing rule: opening it counts as dusting.