Add unit tests for models

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

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

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

Start by locating the store configuration and existing model unit tests; the issue names no paths or entry points. Confirm the expected export behavior and default before adding coverage, then run the relevant test suite to verify the change.

Written by the indexing model from the issue text.