Install nix package without adding to GNOME apps screen

[TLATER]

Specifically this part is probably the best approach:

@jtojnar

User can do something like the following in their NixOS configuration to hide the launcher from the Shell:

{ config, lib, pkgs, ... }:
{
  environment.systemPackages = [
    (lib.hiPrio (pkgs.runCommand "nvim.desktop-hide" { } ''
      mkdir -p "$out/share/applications"
      cat "${config.programs.neovim.finalPackage}/share/applications/nvim.desktop" > "$out/share/applications/nvim.desktop"
      echo "Hidden=1" >> "$out/share/applications/nvim.desktop"
    ''))
  ];
}

Or use NoDisplay instead of Hidden if you want file associations to keep working.

That’s the intended-by-freedesktop mechanism.