feat: German as the main language, English under /en, with a language switch

The site now exists in German (at the root, with /impressum and /datenschutz)
and English (/en). A request without a language follows the visitor's choice
from the language switch, then the browser language, then German; the old
English legal addresses move to /en for good.

All visible texts are data in src/content/de.ts and en.ts, so components hold
none of their own. The header carries a DE/EN switch whose bit curtain covers
the page while it is swapped and reopens at the same reading position. Title,
description, canonical, hreflang, Open Graph, the share image, the sitemap and
the structured data are per language. The privacy notice now describes the
cookie that remembers the chosen language.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/components/Footer.tsx

@@ -1,11 +1,18 @@
+"use client";
+
 import Image from "next/image";
 import Link from "next/link";
 import * as React from "react";
 
 import LogoBlack from "../assets/logo/Logo-Black-Transparent.svg";
+import { pathFor } from "@/src/domain/routes";
 import { BinaryTicker } from "./bits/BinaryTicker";
+import { useContent, useLocale } from "./ContentProvider";
+import { LanguageSwitch } from "./LanguageSwitch";
 
 export const Footer: React.FC = () => {
+  const { nav } = useContent();
+  const locale = useLocale();
   const currentYear = new Date().getFullYear();
 
   return (
@@ -38,24 +45,25 @@ export const Footer: React.FC = () => {
             <span>© {currentYear}</span>
             <div className="flex flex-wrap gap-x-8 gap-y-3 md:justify-end">
               <Link
-                href="/#contact"
+                href={`${pathFor("home", locale)}#contact`}
                 className="hover:text-slate-900 transition-colors duration-300 no-underline"
               >
-                Get in touch
+                {nav.contactLong}
               </Link>
               <Link
-                href="/imprint"
+                href={pathFor("imprint", locale)}
                 className="hover:text-slate-900 transition-colors duration-300 no-underline"
               >
-                Imprint
+                {nav.imprint}
               </Link>
               <Link
-                href="/privacy"
+                href={pathFor("privacy", locale)}
                 className="hover:text-slate-900 transition-colors duration-300 no-underline"
               >
-                Privacy
+                {nav.privacy}
               </Link>
             </div>
+            <LanguageSwitch variant="text" />
             {/* Subtle binary decoration */}
             <span className="flex gap-3 text-[8px] text-slate-300 tracking-[0.5em] select-none font-mono">
               {[77, 73, 78].map((code) => (