Mark invites whose window has closed as expired. Meant for a daily Cloud Scheduler hit.

Open, like the cron payload routes below — the only effect is writing expired onto rows whose window already closed, which the listing reports anyway.

Safe to run repeatedly and safe to miss: only sent/opened rows past their expiry are picked up, and the next run catches up on anything that expired while it was down.

limit is for a cautious first run; leave it off in the schedule.