feat: Passwordless cross-device authentication

- Arkitektur: docs/auth/passwordless-architecture.md
- Backend: iom/quixzoom-auth-service/ (FastAPI + Redis)
- Webb: quixzoom-market-pages/se/login/ (QR-kod + polling)
- App: iom/quixzoom-app/src/features/auth/ (push + deep links)

Flöde: QR-kod → app-godkännande → webb-inloggad

iom/quixzoom-app/App.tsx

@@ -0,0 +1,22 @@
+import { QueryClient, QueryClientProvider } from '@tanstack/react-query'
+import { SafeAreaProvider } from 'react-native-safe-area-context'
+import { AppNavigator } from '@/navigation/AppNavigator'
+
+const queryClient = new QueryClient({
+  defaultOptions: {
+    queries: {
+      staleTime: 30_000,
+      retry: 2,
+    },
+  },
+})
+
+export default function App() {
+  return (
+    <QueryClientProvider client={queryClient}>
+      <SafeAreaProvider>
+        <AppNavigator />
+      </SafeAreaProvider>
+    </QueryClientProvider>
+  )
+}