## Why
Saving an API key does not validate it. Login and status messages should make clear that authentication is checked when a request is sent.
## What changed
Report `API key saved` after API key login and `API key configured` in `login status`. Both messages now explain when authentication is checked.
## Testing
Update the API key login integration test with snapshots for login and status output, while retaining assertions that the key is saved to `auth.json`.
GitOrigin-RevId: 2f36ebb270a48771be25060a596cf9731e8d0325