Add TypeScript types for data

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

**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. Begin by locating the core configuration handling and existing TypeScript type definitions, then determine the intended backup behavior and verify that the new enable_backup option defaults to false.

Written by the indexing model from the issue text.