Add TypeScript types for controllers

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

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

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

The title asks for TypeScript controller types, while the body asks for controller encryption and a new enable_encryption option. No files, tests, or entry points are named, so first reconcile the intended scope in the issue discussion and locate the controller and configuration code. Done criteria are not clear until the requested behavior and type changes are specified.

Written by the indexing model from the issue text.