Refactor container build and installation pipeline to use configurable Makefile parameters (e.g. DISTROS, base images) and propagate them through all build, install, and test scripts

scripts/installation/arch/package.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "[arch/package] Building Arch package (makepkg --nodeps)..."
+
+if id aur_builder >/dev/null 2>&1; then
+  echo "[arch/package] Using 'aur_builder' user for makepkg..."
+  chown -R aur_builder:aur_builder "$(pwd)"
+  su aur_builder -c "cd '$(pwd)' && rm -f package-manager-*.pkg.tar.* && makepkg --noconfirm --clean --nodeps"
+else
+  echo "[arch/package] WARNING: user 'aur_builder' not found, running makepkg as current user..."
+  rm -f package-manager-*.pkg.tar.*
+  makepkg --noconfirm --clean --nodeps
+fi
+
+echo "[arch/package] Installing generated Arch package..."
+pacman -U --noconfirm package-manager-*.pkg.tar.*
+
+echo "[arch/package] Done."