feat: auto-opening brochure modal with mintel/mail delivery

- implemented BrochureDeliveryEmail template

- created AutoBrochureModal wrapper with 5s delay

- updated layout.tsx and BrochureCTA to use new success state

- added tests/brochure-modal.test.ts e2e test

tests/brochure-modal.test.ts

@@ -0,0 +1,65 @@
+import { test, expect, beforeAll, afterAll } from 'vitest';
+import puppeteer, { Browser, Page } from 'puppeteer';
+import { createServer } from 'http';
+import { parse } from 'url';
+import next from 'next';
+
+let browser: Browser;
+let page: Page;
+
+// The URL of the local Next.js server we are testing against.
+// In CI, we expect the server to already be running at http://127.0.0.1:3000
+const BASE_URL = process.env.TEST_URL || 'http://127.0.0.1:3000';
+
+beforeAll(async () => {
+  browser = await puppeteer.launch({
+    headless: true,
+    args: ['--no-sandbox', '--disable-setuid-sandbox'],
+  });
+});
+
+afterAll(async () => {
+  if (browser) {
+    await browser.close();
+  }
+});
+
+test('AutoBrochureModal should open after 5 seconds and submit email', async () => {
+  // Set a long timeout for the test to prevent premature failure
+  page = await browser.newPage();
+
+  // Clear localStorage to ensure the auto-open logic fires
+  await page.goto(BASE_URL);
+  await page.evaluate(() => {
+    localStorage.clear();
+  });
+
+  // Reload page to start the timer fresh
+  await page.goto(BASE_URL, { waitUntil: 'networkidle0' });
+
+  // Wait for auto-trigger (set to 5s in code, we wait up to 10s here)
+  const modal = await page.waitForSelector('div[role="dialog"]', { timeout: 10000 });
+  expect(modal).not.toBeNull();
+
+  // Ensure the email input is present inside the modal (using the placeholder to be sure)
+  const emailInput = await page.waitForSelector('input[name="email"]', { visible: true });
+  expect(emailInput).not.toBeNull();
+
+  // Fill the form matching BrochureCTA.tsx id=brochure-email
+  await page.type('input[name="email"]', 'test-brochure@mintel.me');
+
+  // Submit the form
+  await page.click('button[type="submit"]');
+
+  // Wait for the success state UI to appear
+  await page.waitForFunction(
+    () =>
+      document.body.innerText.includes('Successfully sent') ||
+      document.body.innerText.includes('Erfolgreich gesendet'),
+    { timeout: 10000 },
+  );
+
+  // Verify localStorage was set correctly so it doesn't open again
+  const hasSeenModal = await page.evaluate(() => localStorage.getItem('klz_brochure_modal_seen'));
+  expect(hasSeenModal).toBe('true');
+}, 30000);