Consider deprecating old models API

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

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

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

The issue names no files, tests, or entry points; first reconcile the title about deprecating the old models API with the body about exporting auth. Before implementation, establish the intended scope, configuration behavior, affected code locations, and acceptance criteria for considering the work done.

Written by the indexing model from the issue text.