Rewrite the constraint specs and docs for the service-led information architecture.

Assertions now follow the eighteen prerenderable paths, the gist dialog, and the six-case evidence set.

Co-authored-by: Cursor <cursoragent@cursor.com>

e2e/layout.e2e.ts

@@ -9,13 +9,13 @@ const CHECKED = [
   pagePath('pitch', 'en'),
   pagePath('projects', 'de'),
   pagePath('projects', 'en'),
-  pagePath('servicesAi', 'de'),
+  pagePath('services', 'de'),
   pagePath('contact', 'de'),
   pagePath('imprint', 'en'),
   '/missing-route',
 ];
 
-const VIEWPORTS = [320, 768, 1024, 1440] as const;
+const VIEWPORTS = [320, 390, 768, 1024, 1440] as const;
 
 test.describe('layout and crawlability', () => {
   test('does not overflow horizontally on checked routes', async ({ page }) => {