TIL making .app wrappers on macOS for GUI apps distributed as simple binaries, such as those from pkgsrc, is piss easy.
Step 1: Create a directory named <App Name>.app
Step 2: Symlink the binary into the root of the .app directory with the same name as the directory but without the .app
That's literally it. You don't need to do anything else, it just works. Incredible.

