fix: bun_install adds node_modules to each directory

tests/script_test/run_vite_monorepo_apps.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+app_a_binary="$1"
+app_b_binary="$2"
+workdir="$(mktemp -d)"
+
+server_pid=""
+log_file=""
+
+cleanup() {
+  if [[ -n ${server_pid} ]] && kill -0 "${server_pid}" 2>/dev/null; then
+    kill "${server_pid}" 2>/dev/null || true
+    wait "${server_pid}" 2>/dev/null || true
+  fi
+  rm -rf "${workdir}"
+}
+trap cleanup EXIT
+
+pick_port() {
+  python3 - <<'PY'
+import socket
+sock = socket.socket()
+sock.bind(("127.0.0.1", 0))
+print(sock.getsockname()[1])
+sock.close()
+PY
+}
+
+verify_vite_app() {
+  local binary="$1"
+  local expected_title="$2"
+  local expected_js="$3"
+  local log_name="$4"
+  local port
+
+  port="$(pick_port)"
+  log_file="${workdir}/${log_name}.log"
+
+  "${binary}" --host 127.0.0.1 --port "${port}" --strictPort >"${log_file}" 2>&1 &
+  server_pid=$!
+
+  for _ in {1..60}; do
+    if ! kill -0 "${server_pid}" 2>/dev/null; then
+      cat "${log_file}" >&2
+      echo "Vite server exited unexpectedly for ${log_name}" >&2
+      exit 1
+    fi
+
+    if curl --fail --silent "http://127.0.0.1:${port}/" | grep -Fq "${expected_title}"; then
+      break
+    fi
+
+    sleep 0.5
+  done
+
+  if ! curl --fail --silent "http://127.0.0.1:${port}/" | grep -Fq "${expected_title}"; then
+    cat "${log_file}" >&2
+    echo "Timed out waiting for Vite index page for ${log_name}" >&2
+    exit 1
+  fi
+
+  if ! curl --fail --silent "http://127.0.0.1:${port}/main.js" | grep -Fq "${expected_js}"; then
+    cat "${log_file}" >&2
+    echo "Expected Vite module output was not served for ${log_name}" >&2
+    exit 1
+  fi
+
+  kill "${server_pid}" 2>/dev/null || true
+  wait "${server_pid}" 2>/dev/null || true
+  server_pid=""
+}
+
+verify_vite_app "${app_a_binary}" "Vite monorepo app A" "Hello from monorepo app A" "app-a"
+verify_vite_app "${app_b_binary}" "Vite monorepo app B" "Hello from monorepo app B" "app-b"