fix: package theme engine and system scripts and fix env-update scriptability

features/scripts/utils/nomarchy-sys-update

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+# Nomarchy System Update Script
+# 1. Applies system-wide NixOS changes
+
+set -e
+
+# Apply NixOS changes from the local flake
+echo "Applying system-level changes..."
+sudo nixos-rebuild switch --flake /etc/nixos#default --impure
+
+echo "System update complete."