Seeing it all come together
Now after you save, restart the server, and run your module, the workflow for the sales order will be modified so that you can only confirm orders that have had their art approved.
You will see that not only do the buttons now properly behave with our workflow, the Art Approved state is now displayed in the upper-right corner. The user is getting clear feedback that the art has been approved, and the sales order is now ready to be confirmed.