Deploy QM

Read ../../../deployment.md completely and follow it as the authoritative workflow. Read only the selected provider reference. Read references/email.md before collecting email secrets. Administrators can defer email setup and use qm admin-login; ordinary email sign-in needs a transport. Read references/slack.md only when Slack is requested.

A deployment needs a base model key and a way for people to sign in. Collect both in the same pass. The base model provider is a deployment choice recorded as modelProvider, not a setting to leave for the Admin page. Sign-in is either the built-in auth broker, with optional email setup for an initial admin-only deployment, or an external OIDC provider such as Slack. Read references/email.md once the operator has chosen the broker.

Use the repository's installed @yc-software/qm dependency through npm exec qm -- <command>. Do not require or clone the QM source repository. Do not stop at infrastructure health: complete the acceptance checks and return the handoff required by deployment.md. A web response without a generated sidebar title is not a completed deployment.