Summary

The us-east-3 Datum Connect relay still appears in shell session configuration, but the site it pointed at is retired and the address no longer answers.

Shell sessions skip it today, so nothing breaks. A client that tries it first only waits for a timeout, and the stale entry hides which relays really exist.

Acceptance criteria

• The portal's allowed relay list names only relays that answer
• Shell sessions never offer a retired relay to clients

Related to datum-cloud/enhancements#900