Installs from before the Snapper setup was normalized ran hourly
timeline snapshots. Newer configs stopped creating them but never
deleted the existing ones, and number cleanup skips snapshots marked
Cleanup=timeline, so they sit there forever: one machine installed from
the 2026-05-11 ISO had accumulated 592 of them, silently pinning 219 GB
of disk. The limine-snapper-sync limit-mismatch warning that would have
surfaced this is disabled by default since the notifier migration.
Delete leaked timeline snapshots in batches of 20 (a single mass delete
can die on a DBus timeout partway through), and only when
TIMELINE_CREATE="no" so anyone who deliberately re-enabled timeline
snapshotting keeps their setup untouched.
The drain is best effort: a batch that fails is skipped rather than
aborting the migration run and everything queued behind it, since the
next run re-lists whatever is left.
Martin Bastien
d548c064ee