Add TypeScript types for core

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

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

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

No files, tests, or entry points are named. First clarify what “import for controllers” should import and how it relates to the proposed `enable_import` option, including the expected behavior when its default is `false`; then locate the core type definitions and configuration handling. Done means the intended import behavior is implemented and covered by appropriate tests.

Written by the indexing model from the issue text.