Invitations and roles now follow a clear rank order
- Roles now respect a proper hierarchy — Superadmin > Owner > Admin > Member > Viewer — when you invite people or change someone's role.
- You can only assign roles at or below your own, and only manage members who don't outrank you. The role dropdown now hides any role you're not allowed to grant.
- Superadmins can now assign the Owner role, and admins can no longer promote anyone above themselves.
- An organisation can no longer be left without an owner — demoting the last remaining owner is now blocked.
- Invite and role-change screens now show a clear reason when something isn't allowed, instead of a generic error.