Refactor handlers for better readability

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

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

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

Start by locating the authentication handlers and configuration loading in the repository, then trace where an enable_analytics option would be read. Confirm the expected default is false and identify how auth analytics should be exposed; the work is done when that behavior is defined and covered by the relevant tests.

Written by the indexing model from the issue text.