Add TypeScript types for config

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

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

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

Start by reconciling the title's TypeScript-types request with the body’s encryption feature request, then locate the core configuration entry point. Confirm whether the intended outcome is typed configuration, an `enable_encryption` option, or both, and identify the relevant validation or tests before defining done.

Written by the indexing model from the issue text.