fix: resolve ES modules compatibility in E2E test files

- Replace __dirname with import.meta.url pattern for ES modules compatibility
- Add fileURLToPath imports to all E2E test files
- Fix duplicate require statements in setup-verification.spec.ts
- Update playwright.config.ts to use relative path instead of __dirname

This fixes the 'ReferenceError: __dirname is not defined in ES module scope' error
when running Playwright tests in the ES modules environment.

node_modules/react-dom/server.edge.js

@@ -0,0 +1,17 @@
+'use strict';
+
+var b;
+var l;
+if (process.env.NODE_ENV === 'production') {
+  b = require('./cjs/react-dom-server.edge.production.js');
+  l = require('./cjs/react-dom-server-legacy.browser.production.js');
+} else {
+  b = require('./cjs/react-dom-server.edge.development.js');
+  l = require('./cjs/react-dom-server-legacy.browser.development.js');
+}
+
+exports.version = b.version;
+exports.renderToReadableStream = b.renderToReadableStream;
+exports.renderToString = l.renderToString;
+exports.renderToStaticMarkup = l.renderToStaticMarkup;
+exports.resume = b.resume;