Diagnosis of a live run: caption tracks resolve fine (player + watch-page scrape),
but the timedtext baseUrl fetch returns 429 under back-to-back volume — YouTube
rate-limits the unauthenticated caption-download endpoint per IP. A per-video
delay spaces the fetches. (Follow-up: treat 429 distinctly from genuine
no-caption instead of silently degrading to SourceNone; consider Whisper if the
endpoint stays hostile at any sustainable rate.)
RunOnce walks the user's subscriptions, upserts each candidate video (assigning
its durable store id), skips videos already summarized via the store's
SeenVideoIDs (cross-restart dedup the engine's in-memory map can't provide),
and processes the rest through the engine. Loop adds an optional poll cadence;
per-item errors are collected, not fatal. Tested with fakes — no live deps.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>