Improve error messages in auth

**Feature request**
It would be great to have export for data.

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

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

No files, tests, or entry points are named. Start by locating the authentication configuration and any existing data-export entry point, then determine the expected exported data and verify that the new enable_export option defaults to false and enables the requested production use case.

Written by the indexing model from the issue text.