Implement integration tests with Playwright

tests/auth.spec.ts

@@ -0,0 +1,31 @@
+import { test, expect } from '@playwright/test';
+
+test.describe('Authentication', () => {
+    test('Public pages should be accessible without login', async ({ page }) => {
+        await page.goto('/');
+        await expect(page).toHaveTitle(/Hördle/);
+        await expect(page.getByRole('button', { name: 'Start' })).toBeVisible();
+    });
+
+    test('Admin page should be protected', async ({ page }) => {
+        await page.goto('/en/admin');
+        // We expect to see the Login form, NOT the dashboard content
+        await expect(page.getByPlaceholder('Password')).toBeVisible();
+        await expect(page.getByText('Manage Specials')).not.toBeVisible();
+    });
+
+    test('Admin login flow', async ({ page }) => {
+        // Navigate to admin login
+        await page.goto('/en/admin');
+
+        const passwordInput = page.getByPlaceholder('Password');
+
+        if (await passwordInput.isVisible()) {
+            await passwordInput.fill('admin123');
+            await page.getByRole('button', { name: 'Login' }).click({ force: true });
+
+            // Should now be on admin page
+            await expect(page.getByRole('heading', { name: 'Hördle Admin Dashboard' })).toBeVisible();
+        }
+    });
+});