A watched video the catalog did not know at import time waits in `takeout_items`. The Shorts job now
settles those rows right after its probe (the only place a video's Short-ness becomes known), every
user's, a commit each: `reader.takeout.apply_waiting`, its count in the job's result.
`GET /api/takeout` is what the settings page reads: the user's last import run (`jobruns.last_run`)
and the kept videos by kind and outcome, "waiting" for one not known yet.