Convert test-runner.ts to test-runner.cjs to fix ES module error

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

.storybook/test-runner.cjs

@@ -0,0 +1,13 @@
+/**
+ * @type {import('@storybook/test-runner').TestRunnerConfig}
+ */
+module.exports = {
+  async preVisit(page) {
+    // Inject __test global to prevent ReferenceError during test execution
+    // This addresses the error: "page.evaluate: ReferenceError: __test is not defined"
+    // that occurs when running Storybook test-runner smoke tests
+    await page.evaluate(() => {
+      window.__test = true;
+    });
+  },
+};