Make Verified Feed refresh repeatable and demo-safe

[azizu06]

Parent

#25

What to build

Make the Verified Feed refresh safe to demonstrate one or two times in front of judges. Two consecutive refreshes must remain idempotent, show truthful progress and counts, preserve the existing catalog when external services fail, and end with a newly accepted video when a suitable candidate is available.

Acceptance criteria

• A unique YouTube video constraint and upsert behavior prevent duplicate cards across consecutive refreshes.
• Only one refresh may run at a time; duplicate clicks are disabled and explained.
• Refresh runs persist started/completed/failed state and discovered, analyzed, kept, rejected, and duplicate counts.
• YouTube quota, Gemini rate-limit, timeout, no-acceptable-candidate, and Supabase failure paths preserve the last good catalog and offer safe retry guidance.
• Fixture-backed E2E runs twice and proves idempotency without live credentials.
• One opt-in local integration test uses real YouTube discovery plus Gemini analysis and records evidence without making live credentials a CI requirement.
• Browser QA covers desktop/mobile layout, every button/link/route, keyboard focus, embed behavior, console health, and absence of framework overlays.
• README and demo notes explain exactly how to seed, refresh, retry, and fall back to the persisted catalog.

Blocked by

• Refresh the feed with one vetted YouTube candidate #28
• Expand the searchable Verified Feed experience #29