fix: mobile nav close button + CI Gatekeeper auth

- Add explicit close (×) button inside mobile nav overlay
  - Was unreachable because header's hamburger was behind overlay z-index
  - New button lives inside the overlay at full z-index visibility
- Fix check-forms.ts: authenticate via Gatekeeper login form
  - Old approach: inject raw password as session cookie (didn't work)
  - New approach: navigate to protected page, detect Gatekeeper gate,
    fill password form and submit to get a real server-signed session cookie
  - Fixes E2E form tests that failed because pages returned Gatekeeper HTML

scripts/check-forms.ts

@@ -66,16 +66,29 @@ async function main() {
 
   const page = await browser.newPage();
 
-  // 3. Inject Gatekeeper session bypassing auth screens
-  console.log(`\n🛡️ Injecting Gatekeeper Session...`);
-  await page.setCookie({
-    name: 'klz_gatekeeper_session',
-    value: gatekeeperPassword,
-    domain: new URL(targetUrl).hostname,
-    path: '/',
-    httpOnly: true,
-    secure: targetUrl.startsWith('https://'),
-  });
+  // 3. Authenticate through Gatekeeper login form
+  console.log(`\n🛡️ Authenticating through Gatekeeper...`);
+  try {
+    // Navigate to a protected page so Gatekeeper redirects us to the login screen
+    await page.goto(contactUrl, { waitUntil: 'networkidle0', timeout: 30000 });
+
+    // Check if we landed on the Gatekeeper login page
+    const isGatekeeperPage = await page.$('input[name="password"]');
+    if (isGatekeeperPage) {
+      await page.type('input[name="password"]', gatekeeperPassword);
+      await Promise.all([
+        page.waitForNavigation({ waitUntil: 'networkidle0', timeout: 30000 }),
+        page.click('button[type="submit"]'),
+      ]);
+      console.log(`✅ Gatekeeper authentication successful!`);
+    } else {
+      console.log(`✅ Already authenticated (no Gatekeeper gate detected).`);
+    }
+  } catch (err: any) {
+    console.error(`❌ Gatekeeper authentication failed: ${err.message}`);
+    await browser.close();
+    process.exit(1);
+  }
 
   let hasErrors = false;