Copied from #977: - [ ] Single Sign On using Apache REMOTE_USER header. [Auth_remoteuser](https://www.mediawiki.org/wiki/Extension:Auth_remoteuser) (needs Debian packaging?) - [ ] Checkbox to [disable user registrations](https://www.mediawiki.org/wiki/Extension:LDAP_Authentication/User_Provided_Information#Deactivating_New_User_Signup_.2F_Registration) (should still allow new Plinth users)