feat: single-page redesign with text-only hero, team section, services grid, mobile nav

- Replace component-based index with unified inline page
- Add text-only hero with warm editorial typography
- Add team section with avatars and bios
- Convert services to responsive grid layout
- Add contact labels and editorial images
- Implement mobile hamburger navigation with slide-in panel
- Polish typography, spacing, and accessibility
- Remove design variant pages (1-6)

src/components/sections/FinalCta.astro

@@ -0,0 +1,13 @@
+---
+import { siteContent } from "@/content/site-content"
+---
+
+<section class="final-cta" aria-labelledby="final-cta-title">
+  <p class="eyebrow">Bereit für den nächsten Schnitt?</p>
+  <h2 id="final-cta-title">Kurz anrufen, Termin abstimmen, vorbeikommen.</h2>
+  <div class="final-cta-actions">
+    <a class="button-link button-link--light" href={siteContent.cta.primary.href}>
+      {siteContent.business.phone.display}
+    </a>
+  </div>
+</section>