Adds per-record edit mode and retry to the source detail page, plus a
CLI `second-brain retry <id>` for parity.
Edit mode exposes domain (select), title, focus on /sources/{id}.
URL stays read-only — it's the UNIQUE dedupe key and the embeddings
identity tuple. Save goes through a new service helper
`update_source_metadata` so the web route stays a thin wrapper.
Retry exposes two modes, both available on any record:
- full: status -> PENDING (re-pull + re-process)
- extract: status -> TRANSCRIBED (re-extract only, requires an
existing transcript; offered when source_type=video and a
transcript is present, to avoid the expensive re-download path)
Both modes clear claimed_by/claimed_at and error_message so the queue
dance picks it up cleanly.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
