feat(i18n): migrate hardcoded German strings to t() across 104 components/pages — AST-based batch with re-parse gate, 423 new de.json keys; tsc clean; vitest failures byte-identical to clean-tree baseline (pre-existing)

frontend/src/routes/index.tsx

@@ -13,6 +13,7 @@ import { PasswordResetConfirmPage } from '@/pages/PasswordResetConfirm';
 import { Loader2 } from 'lucide-react';
 import { PluginRouteRenderer } from '@/components/plugins/PluginRouteRenderer';
 import { ErrorBoundary } from '@/components/common/ErrorBoundary';
+import { useTranslation } from 'react-i18next';
 
 // Lazy-loaded pages (code-splitting)
 const DashboardPage = React.lazy(() => import('@/pages/Dashboard').then(m => ({ default: m.DashboardPage })));
@@ -91,8 +92,9 @@ const SystemDashboardPage = React.lazy(() => import('@/pages/SystemDashboard').t
 
 /** Centered spinner fallback for lazy-loaded routes */
 function PageLoader() {
+  const { t } = useTranslation();
   return (
-    <div className="flex items-center justify-center min-h-[50vh]" role="status" aria-label="Seite wird geladen">
+    <div className="flex items-center justify-center min-h-[50vh]" role="status" aria-label={t('index.seitewirdgeladen')}>
       <Loader2 className="animate-spin h-8 w-8 text-primary-500" aria-hidden="true" />
     </div>
   );