docs: document Clerk German localization, mark Capacitor mobile plan superseded

- README: note @clerk/localizations' deDE usage in the tech stack table
  and shipped-features list.
- ClerkThemeProvider: comment explaining why deDE is needed (Clerk's own
  UI defaults to English regardless of the app's next-intl locale).
- mobil.md: mark the Capacitor plan superseded by the React Native/Expo
  scaffold decided this session (see mobile/README.md).

README.md

@@ -18,7 +18,7 @@ A social platform where pets are the stars. Dogs, cats, birds, horses, rabbits,
 | API | tRPC | 11.x |
 | ORM | Prisma | 7.x |
 | Database | PostgreSQL via Supabase (managed) | 16 |
-| Auth | Clerk (+ `@clerk/themes` for dark-mode-aware Clerk UI) | 7.x |
+| Auth | Clerk (+ `@clerk/themes` for dark-mode-aware UI, `@clerk/localizations`' `deDE` for German auth UI text) | 7.x |
 | Media Storage | Supabase Storage (S3-compatible, presigned uploads) | — |
 | Cache / Feed / Rate Limiting | **Self-hosted Redis** (`ioredis`, Docker service — not Upstash) | 5.x |
 | Client Fetching | TanStack Query | 5.x |
@@ -433,7 +433,7 @@ Owner (Clerk account, auth only)
 
 Foundation → content core → engagement → notifications → video → messaging → health tracking are all live, plus a full production layer built after MVP:
 
-- **i18n** — next-intl EN/DE, species/breed translation tables (legal pages stay fixed-German)
+- **i18n** — next-intl EN/DE, species/breed translation tables (legal pages stay fixed-German); Clerk's own sign-in/sign-up UI is localized to German via `@clerk/localizations`' `deDE` (2026-09-01)
 - **Dark mode** — account-bound (`Owner.themePreference`), synced across Clerk's own UI
 - **Admin/moderation panel** — users, posts, reports, ads, invites, verification, audit log, 3-tier role matrix
 - **Invite system** — beta gate, now disabled for public launch

mobil.md

@@ -1,6 +1,13 @@
-# PawFeed Mobile — Nebenplan
+# PawFeed Mobile — Nebenplan (überholt)
 
-## Ausgangslage
+> **Überholt seit 2026-09-01:** Die Entscheidung fiel auf React Native/Expo
+> statt Capacitor — echte native App statt Web-Wrapper, spricht direkt über
+> tRPC mit dem bestehenden Docker-Backend (kein Neu-Schreiben des Backends
+> nötig). Start mit Android. Aktueller Stand: `mobile/README.md`. Dieses
+> Dokument bleibt nur als Kontext, warum Capacitor erwogen und verworfen
+> wurde.
+
+## Ausgangslage (historisch)
 
 Die Web-App läuft auf Next.js. Kein Neu-Schreiben nötig — die App wird nur verpackt.
 

src/components/providers/ClerkThemeProvider.tsx

@@ -15,6 +15,9 @@ export function ClerkThemeProvider({ children }: { children: React.ReactNode })
 
   return (
     <ClerkProvider
+      // Clerk's own UI (sign-in, sign-up, password reset, ...) defaults to
+      // English regardless of the app's own next-intl locale — deDE is
+      // Clerk's official translation, not a hand-rolled string override.
       localization={deDE}
       appearance={{
         baseTheme: isDark ? dark : undefined,