Improve error messages in auth

**Feature request**
It would be great to have logging for auth.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_logging` with default `false`.

No files, tests, or entry points are identified in the issue. Start by locating authentication handling, configuration parsing, and existing logging paths, then trace how auth failures and events are surfaced. Done means an enable_logging option defaults to false and production authentication logging behaves as specified, with tests covering both settings.

Written by the indexing model from the issue text.