Clicking "get full history" now kicks an immediate background deep
backfill of that one channel (backfill_channel_now: own session, up to
~3000 videos in one pass, quota-guarded) instead of waiting for the
scheduler's paced 10-minute ticks (5 pages/channel/tick). The request
returns instantly and the channel page's live poll shows the count fill
in seconds. A very large channel's tail still falls to the scheduler
(deep_requested stays set).
peter
a342e15e05