feat: add phase 2 bun_install repository rule bootstrap

tests/install_test/clean_install.sh

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+bun_path="$1"
+workdir="$(mktemp -d)"
+trap 'rm -rf "${workdir}"' EXIT
+
+cat > "${workdir}/package.json" <<'JSON'
+{
+  "name": "clean-install-test",
+  "version": "1.0.0"
+}
+JSON
+
+"${bun_path}" install --cwd "${workdir}" >/dev/null
+rm -rf "${workdir}/node_modules"
+"${bun_path}" install --cwd "${workdir}" --frozen-lockfile >/dev/null
+
+if [[ ! -d "${workdir}/node_modules" ]]; then
+  echo "Expected node_modules to be created" >&2
+  exit 1
+fi