- Settings -> System -> Roles (summercms.cabana.roles, backend.manage_roles,
order 110): name, code slugged from the name, description, checkbox
permission editor with the editor's ceiling
- system roles (is_system or code-declared grants) keep their code and
cannot be deleted; a role any admin holds (deleted ones included) cannot
be deleted, the refusal names the role and the count
- role codes unique among roles