How do I register new permissions?

You can add new permissions by using \Aero\Admin\Permissions:

// Add a single permission
\Aero\Admin\Permissions::add('acme.view');

// Add multiple permissions
\Aero\Admin\Permissions::add([
    'acme.view', 
    'acme.add', 
    'acme.edit',
    'acme.delete',
]);