Support backup configuration

**Feature request**
It would be great to have notifications for config.

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

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

Start by locating the configuration definition and any existing notification or backup handling; the issue names no files or tests. Clarify which configuration events should notify users and how notifications are delivered, then verify that enable_notifications defaults to false and the agreed notification behavior works.

Written by the indexing model from the issue text.