Add TypeScript types for config

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

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

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

No file, test, or entry point is named. First clarify whether the task is to add TypeScript config types or implement backup hooks, then locate the configuration definitions and hook handling; done should include the enable_backup option with a false default and coverage for the intended behavior.

Written by the indexing model from the issue text.