E32 review round 1 (B7). Each phase took its own now; phase 2's "not checked this run" test then
let a just-recovered video through and spent another videos.list call on it.
The catalog prune and the subscription import have long refused to reconcile against an empty
listing that contradicts what we hold (should_prune: a 200 with no items is a blip far more often
than a user who removed everything). Two mirrors did not: the YouTube playlist mirrors (dropped
every mirror) and the Plex collections (dropped every collection with its user-set `editable`
flag, and every member's keys — the guard landed in plex/sync.py with the previous commit). Both
now hold the same rule; test_empty_listing_guards covers each way (seen red).
sync/maintenance (19% covered) gets a lifecycle test: recover, grace, delete + one notification
per user, live stream kept, abandoned premiere. It found the rolling revalidation re-fetching the
same videos until `checked` reached the batch (15000 by default) whenever fewer videos were
available — quota spent on answers it already had; a run now skips what it has checked.