Delimit Guided Tours by content of course of origin

Guided Tours usually™ happen in the context of a course. If so, we think we want to limit the guided tours to the scope of that course. That is to say, only go as deep as what the course itself explains. Dependency chains would cut off (= make leaf-concepts) those concepts defined in the course that only refer to things out-of-course.

For everything that happens outside of a dedicated course, it would be thinkable to have a universal "rabbit hole" context that goes as deep as the content model allows. It should be possible to switch from one to the other in the same guided tour, but only upon request.