Unsung's unread counted 2 in the feed list while All Subscriptions'
unread list was empty. It had been a show of an OPML that is hidden
from All Subscriptions, and became a feed of its own; Db::unmanage set
managed = false and left feeds.group_id pointing at the OPML, so
shown_in hid it with the list. 20 feeds in production were like it.
unmanage now sets the group from the feed's catalogue entry: none for
a show promoted when its list dropped it or went away, the list's for
a show promoted by editing its settings, which config keeps in the
group. A pass at start-up moves those already left behind.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>