In my system, there are two main components: projects and proposals. Each proposal can exist in one of three states - pending, approved, or rejected. A project is always associated with a previously approved proposal. The API endpoint for proposals (/proposals/:id) allows PATCH requests to update the state of a proposal. Furthermore, there is a separate endpoint for projects (/projects) where POST requests create new projects. I am looking to prevent PATCH requests that attempt to change a proposal's state to approved, redirecting them instead to the /projects endpoint. What would be the appropriate status code to use in this particular scenario?