add /etc/current-system-packages to vms

hosts/virtual-machines/template.nix

@@ -1,7 +1,7 @@
 # Edit this configuration file to define what should be installed on
 # your system. Help is available in the configuration.nix(5) man page, on
 # https://search.nixos.org/options and in the NixOS manual (`nixos-help`).
-
+{ pkgs, config, ... }:
 {
   boot.loader.systemd-boot.enable = true;
   boot.loader.efi.canTouchEfiVariables = true;
@@ -21,5 +21,14 @@
 
   services.qemuGuest.enable = true;
 
+  # Add /etc/current-system-packages
+  environment.etc."current-system-packages".text =
+    let
+      packages = builtins.map (p: "${p.name}") config.environment.systemPackages;
+      sortedUnique = builtins.sort builtins.lessThan (pkgs.lib.lists.unique packages);
+      formatted = builtins.concatStringsSep "\n" sortedUnique;
+    in
+    formatted;
+
   system.stateVersion = "24.11";
 }