Ideally, connlib would treat resource_created_or_updated with a change in the sites as an addressability change, the same way we treat address / ip_stack changes.

What we have to do now is a hack - anytime a resource's sites change, we send resource_deleted followed by resource_created_or_updated. This requires tracking more state in the portal to determine if a resource has lost all its sites, and if so, refrain from sending the resource_created_or_updated.