Refactor ProjectService to be part of Project model
This is really confusing design, it took me a while to figure out how the company contact is set. I think dealing with the roles necessary to make a User company contact of a Project should be handled by the model, in callbacks, because it does not depend on the controller in which the Project is managed.
Also, a service is generally a standalone class and not a module included in a controller: I would prefer to use a controller concern in the latter case. In my opinion, services are best used to implement some high-level processes (maintenance) or interfacing with external systems (APIs).