Add Node.js version gate and fix ESM path resolution

package.json

@@ -3,6 +3,9 @@
   "version": "2.0.0",
   "description": "Opinionated macOS development environment setup tool with beautiful TUI",
   "type": "module",
+  "engines": {
+    "node": ">=18.0.0"
+  },
   "scripts": {
     "start": "node src/cli.js",
     "setup": "node src/cli.js setup",

src/cli.js

@@ -1,5 +1,8 @@
 #!/usr/bin/env node
 
+import { checkNodeVersion } from "./utils/node-version.js";
+checkNodeVersion();
+
 import { runSetup } from "./setup.js";
 import { runAppend } from "./append.js";
 import { runVerify } from "./verify.js";

src/utils/fs.js

@@ -7,6 +7,7 @@ import {
   copyFileSync,
 } from "node:fs";
 import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
 import { homedir } from "node:os";
 
 /**
@@ -94,5 +95,5 @@ export function expandHome(p) {
  * Get the suitup project root (where configs/ lives).
  */
 export function projectRoot() {
-  return join(import.meta.dirname, "..", "..");
+  return join(dirname(fileURLToPath(import.meta.url)), "..", "..");
 }

src/utils/node-version.js

@@ -0,0 +1,33 @@
+/**
+ * Validates that the current Node.js runtime meets the minimum version
+ * required for native ESM support (including stable top-level await).
+ *
+ * Minimum supported version: Node.js 18.0.0 (Active LTS)
+ */
+
+const MIN_MAJOR = 18;
+
+/**
+ * Parse the major version number from a Node.js version string.
+ * @param {string} version - e.g. "v18.17.0"
+ * @returns {number}
+ */
+function parseMajor(version) {
+  return parseInt(version.replace(/^v/, "").split(".")[0], 10);
+}
+
+/**
+ * Check that Node.js is new enough to support native ESM.
+ * Exits the process with a helpful message if not.
+ */
+export function checkNodeVersion() {
+  const major = parseMajor(process.version);
+  if (major < MIN_MAJOR) {
+    console.error(
+      `suitup requires Node.js ${MIN_MAJOR} or later for native ESM support.\n` +
+        `You are running Node.js ${process.version}.\n` +
+        `Please upgrade: https://nodejs.org/en/download`
+    );
+    process.exit(1);
+  }
+}