Expose home-manager-built programs

[noteed]

Description

I'd like to write a derivation that exposes, say, the neovim configured by the home-manager module system (without actually using home-manager to manage my home directory).

In practice, I can use something like

let
  sources = import ./nix/sources.nix;
  pkgs = import sources.nixpkgs { };
  home-manager = import "${sources.home-manager}/home-manager/home-manager.nix" {
    inherit pkgs;
    confPath = ./conf.nix; # Contains mostly `programs.neovim.enable = true;`
  };
in
{ 
  neovim = pkgs.stdenv.mkDerivation {
    name = "home-manager-neovim";
    src = ./.;
    installPhase = ''
      mkdir -p $out/bin
      cp ${home-manager.activationPackage}/home-path/bin/nvim $out/bin/
    '';
  };
}

but I feel like accessing cfg.programs.neovim.finalPackage would be cleaner than going through ${home-manager.activationPackage}/home-path.

Would it be possible to add function in the top-level default.nix file of this repository to achieve this ?

Note: I think this is similar to this issue #2633.

Note: As for additional context, I was reading this blog post https://wickstrom.tech/2024-08-12-a-flexible-minimalist-neovim.html and was initially puzzled by how neovim was configured, as I couldn't find those options in NixOS. It's only later that I noticed the author was actually using home-manager. I was interested in trying the author's advices, but I'm not a home-manager user.