How to present a SwiftUI scene from AppKit

Issue #1053 &#xA; Plenty of Mac apps still run on an NSApplicationDelegate . The lifecycle works, the windows are wired up, and rewriting everything into the SwiftUI App protocol just to gain one settings window is hard to justify. The friction shows up the moment you want a modern scene like Settings or MenuBarExtra , because those are SwiftUI scenes and a SwiftUI scene normally lives inside a…