Improve config performance

**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`.

The issue names no files or tests. Start by locating the configuration entry point and the authentication code, then trace how authentication events are handled; done means a documented `enable_logging` option defaults to `false` and controls auth logging without changing default behavior.

Written by the indexing model from the issue text.