course: strongly discourage students from moving/renaming/deleting folders that were created by the course management system

[williamstein]

In a course project, various folders get created, e.g., for assignments, handouts, peer grading, returned assignments etc. Students have the technical power to rename, move, delete, etc. any of those files, and that will always be the case, because they can execute arbitrarily shell commands in their project, e.g., in a terminal. However, CoCalc could at least discourage them from doing so via our graphical UI.

Right now there is nothing in place to facilitate this. However, here's one idea:

• When a course pushing out an assignment (etc), include a hidden file, e.g., .course at the top level of the folder.
• When doing the move and delete file actions, check if the project is a course project (i.e., this is in the database). If this is the case, do a little extra work to see if the move or delete action will impact any .course files. If so, display a warning.