Each yt-dlp call is now an independent task (one search query, one trending
fetch, one graph channel fetch). Tasks are shuffled together so we don't fire
10 searches in a row, then enqueued with 30-90s random gaps between them —
a full sweep of ~17 tasks completes in roughly 10-25 minutes instead of
hammering YouTube with 21 calls back-to-back.
Fast signals (community, category clusters) still run synchronously at
schedule time since they're pure SQL.
Progress is tracked per-user (total/done/running) and exposed on
GET /api/discovery/status. The Discovery page polls every 10s while
running and shows a progress bar + "Finding channels… X / Y" in the header.
The auto-discovery daemon skips scheduling if a manual sweep is already running.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>