What should happen when a (person) user should no longer have access?
If we hard-delete the user, the events and acks made by that user will also disappear.
If a user has lost their Feide-account, they can no longer log in with Feide. But there are also local accounts.
Another possibility is to use the "is_active"-flag: logging in is allowed as long as is_active is True. We might have to check that this is currently honored in that case.
the is_active flag on the user model was created for this exact purpose: I second using this solution.
#1449 makes it easy to toggle is_active from CLI.
We do not delete users, only set them as is_active = False.
If GDPR-delete needed, erase info from the user row instead of hard delete.