YouTube reports a 24/7 stream's archive with the years it has run (prod: 122,962,914 s), and one
such video made the Watch later total read 44,073 hours. A length past a day is now no length
(`Video.length_seconds`, LENGTH_MAX_S): the API sends none, the playlist and channel totals
leave it out and count it as `live_without_length` ("+N live" beside the sum), and the duration
filter, sort and Home budget never match it. Migration 0117 moves the duration sort indexes onto
the length expression. An AST test holds who may still read the raw column.
The migration 0110 test now ends its read before the way down: 0117 builds an index
CONCURRENTLY there, which waited for that open transaction forever.
An interval override was a row of its own table beside the one store every other admin knob uses; it
is now the `job_interval_<job>` sysconfig key (migration 0110 copies them over and drops the table).
The Scheduler page stays its one editor: the Configuration page and the setup wizard neither list nor
write those keys, since a write there would skip the reschedule.
Each ConfigSpec now states `applies` (required, no default). Every key is `live`, held by a scan that
finds no read at import time; a `restart` key is refused until the page can say so. A second scan
requires a reader for every key on the Configuration page — `sponsorblock_default` had none since it
was added, so it leaves the registry, the translations and the store.
peter