[Bug]: SQL login failure surfaces as Kestrel TaskCanceledException

## Expected

Database connectivity failures during startup should appear clearly at default verbosity.

Example:

```text
ERROR: Could not connect to database.
Login failed for user ''.
```

## Actual

The visible error is a Kestrel `BindAsync` `TaskCanceledException`, which looks like a port binding issue. The real `Login failed` message is only visible in verbose logs.

This sends users down the wrong troubleshooting path.