Any suggestions as to how those rules for professional conduct would be enforced?

A lawyer can be disbarred, and this is easy to enforce because they can't go into a courtroom and defend or prosecute afterwards.

Developers have no equivalent. There is no way to dictate who can and can't work as a developer. Perhaps you could create some sort of agency that every developer needs to be a part of to work, but I don't ever see developers all agreeing to give an organization that much power.