POST /paste: parse the video id, fetch metadata via the VideoFetcher port (Data
API, ungated), upsert a subscription-less row scoped to the user (idempotent =
dedup), and — unless already summarized — RequestSummarize + start immediate
processing through the SAME globalFetchGate as the Summarize button. Explicit
paste overrides the recency window; a captionless video degrades to the honest
'no transcript' terminal state via the engine (ADR-010). Invalid URL -> 400,
not-found -> 404, both add nothing. Route mounts only when a Fetcher is wired.
Moves the video-not-found sentinel to domain (shared by adapter + web, no
cross-adapter coupling). Tests: valid add+queue, invalid, not-found, dedup.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
