fix: clarify interactive mode detection in package installation script

packages/install.sh

@@ -101,7 +101,8 @@ install_package_lists() {
 
     # Determine which groups to install
     local selected_groups=()
-    if is_interactive; then
+    # Determine interactive mode: forced via INTERACTIVE=1 or a real interactive shell
+    if [ "${INTERACTIVE:-0}" -eq 1 ] || is_interactive; then
         echo "Available package groups:"
         for pkg in "${package_files[@]}"; do
             if [ -f "$packages_dir/$pkg" ]; then