feat: pre-activate standalone Home Manager environment in VM and Live ISO

core/system/vm-guest.nix

@@ -1,6 +1,20 @@
-{ inputs, lib, ... }:
+{ inputs, lib, pkgs, homeActivationPackage ? null, ... }:
 
 {
+  # Pre-activate standalone home-manager if provided
+  system.activationScripts.home-manager-activate = lib.mkIf (homeActivationPackage != null) {
+    text = ''
+      USER_HOME="/home/nomarchy"
+      if [ ! -d "$USER_HOME" ]; then
+        mkdir -p "$USER_HOME"
+        chown nomarchy:users "$USER_HOME"
+      fi
+      # Run activation as the nomarchy user
+      ${pkgs.sudo}/bin/sudo -u nomarchy ${homeActivationPackage}/activate
+    '';
+    deps = [ "users" ];
+  };
+
   # Shared VM configuration
   virtualisation.vmVariant = {
     virtualisation.graphics = true;