Add TypeScript types for lib

**Feature request**
It would be great to have backup for models.

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

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

The issue names no files, tests, or entry points, and its title does not match the requested backup configuration. First locate the configuration handling and model lifecycle in the repository, then clarify the backup behavior and affected platforms; done should include the new option defaulting to false and a test or documented verification of its effect.

Written by the indexing model from the issue text.