Enable full ESM support for Node 20+ and modern dependencies, update Jest and build output configuration

- Set "type": "module" in package.json to enable ESM throughout the project.
- Changed "main" in package.json to "dist/index.js" to point to the bundled output generated by ncc.
- Updated Jest configuration (jest.config.js) to ESM format and to use babel-jest for TypeScript transformation.
- Added/updated babel.config.js in ESM format to support TypeScript and ESM for Jest.
- Ensured test scripts use NODE_OPTIONS=--experimental-vm-modules for Jest ESM compatibility.

babel.config.js

@@ -1,6 +1,12 @@
-module.exports = {
+export default {
   presets: [
-    ['@babel/preset-env', { targets: { node: 'current' } }],
-    '@babel/preset-typescript',
-  ],
+    [
+      '@babel/preset-env',
+      {
+        targets: { node: 'current' },
+        modules: false
+      }
+    ],
+    '@babel/preset-typescript'
+  ]
 };