Channel, Subscription, Video, SearchFind, ExploredChannel and BlockedChannel (and LIVE_OR_UPCOMING)
leave app/models.py for app/catalog/models.py; app.tables registers them. The User↔Subscription
relationship names its other side as a type only. No schema change.
YouTube's RSS goes dark per channel for hours (prod 2026-09-18/19: 393 of
396 feeds answered 404 for four hours, sticky per channel, so a retry does
not help), and nothing else read a followed channel's new uploads. A
channel whose feed has not answered for `rss_fallback_hours` (admin knob,
default 2, 0 = off) now gets one page of its uploads playlist through the
Data API (1 unit), at most once per window, yielding to the backfill
reserve. Spend is attributed to its own quota action.
The scheduled RSS poll and recent backfill covered every channel row,
but rows also come from search results, playlist sync and dropped
subscriptions, and nothing deletes them. On prod 582 of 979 polled
channels had no follower, three of them dead feeds answering 404 on
every poll. Both jobs now take subscribed or explored channels only,
and the scheduler card counts the same set. As a deliberate trade-off,
the shared Library no longer receives new uploads from channels nobody
follows.