- docs/federation/SETUP.md (NEW, 119 lines): what federated is,
prerequisites, docker compose start, config snippet, mosaic gateway
doctor health check, troubleshooting (port conflicts, pgvector errors,
Valkey connection)
- docs/guides/migrate-tier.md (NEW, 147 lines): when to migrate, dry-run
first, what gets migrated/skipped (with rationale for accounts +
provider_credentials), idempotency + advisory-lock semantics, manual
verification queries, no in-place rollback
- README.md: 1-line blurb in Configuration section linking to both
All commands verified against actual CLI surface in
packages/storage/src/cli.ts and packages/mosaic/src/commands/gateway-doctor.ts.
Refs #460
