MILWAUKEE — For attendees of the Republican National Convention, there’s nothing remotely subtle about the role of the Heritage Foundation — the Washington, D.C.-based conservative group behind the highly contentious Project 2025 “presidential transition” plan. Fly into Milwaukee Mitchell International Airport, and the first evidence that the GOP convention is taking place in this Wisconsin city is a set of giant signs that read: “Heritage welcomes you to the RNC Convention in MKE.” A digital billboard inside the airport atrium flashes a similar message. Want more breaking political news? Clic…