Why:
- nothing over HTTP could create the first tenant: every /v1 route needs an API
key, and a key cannot exist before its tenant. The service was unusable by a
human without hand-written SQL.
Changes:
- add `provision_tenant`, owning tenant reuse-or-create, key generation and
hashing, and domain registration in one transaction
- expose it as `python -m src.cli.provision_tenant`, alongside
`alembic upgrade head` and `qdrant_bootstrap`
- add `tenants.get_by_slug`/`create` and `api_keys.create`
- log `tenant.provisioned` / `api_key.provisioned` with the key prefix only
Impact:
- a third deployment step; the plaintext key is printed once and never logged
or stored (ADR-0011, ADR-0009)
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
