FEAT-3: litter type+CRUD, Zucht strings, /wuerfe nested routes (retire LittersPage)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

gerbil-manager-web/src/pages/WuerfeListPage.tsx

@@ -0,0 +1,10 @@
+import { de } from '../strings/de'
+
+export default function WuerfeListPage() {
+  // Fleshed out in the next FEAT-3 increment (Gridify list, year filter, sort).
+  return (
+    <section className="page">
+      <h2>{de.pages.litters.title}</h2>
+    </section>
+  )
+}