Add configuration options for caching

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

**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 or tests. Start by locating the configuration handling and existing caching implementation, then clarify what configuration backup should include and where it is stored. Done means adding an `enable_backup` option that defaults to `false`, with coverage for the option's behavior.

Written by the indexing model from the issue text.