Refresh Embeddings Endpoint

Kick off today's AI Search embedding refresh and return at once. Runs after the scrapes.

Two passes. Creators with no embedding at all are cleared first — until a creator has one they are invisible to semantic narrowing, and the scrapers add roughly 5,000 a day. Then a capped pass over creators whose profile row has moved since their embedding was written, so an enriched bio eventually gets a vector that matches it.

Safe to run repeatedly and safe to miss: candidates are computed from the data rather than from a schedule, so a second run the same day is close to a no-op and a missed night is picked up by the next one. Queued — the initial backfill of 24,673 creators took 24 minutes.