Kairos is about to start announcing rendered mail documents to
POST /library/api/ingest/ with source="kairos-mail". Without a registry
entry, unknown sources fall back to the daedalus bucket and every worker
fetch fails — this adds the KAIROS_S3_* env vars (pattern-copy of the
spelunker block) and the SOURCE_S3_BUCKETS["kairos-mail"] entry, plumbed
through .env.example and the worker service in docker-compose.
Settings-only; no code changes.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
