updates for modular format

modules/darwin/services.nix

@@ -0,0 +1,10 @@
+{ config, pkgs, ... }:
+
+{
+  # Example: Tailscale, other system services
+  services.nix-daemon.enable = true;
+  services.tailscale.enable = true;
+
+  # Example: you could also place security/pam or other service configs here:
+  security.pam.enableSudoTouchIdAuth = true;
+}