Working React 19 before Compiler integration

🚀 Phase 2 Complete - React 19 Foundation
- React upgraded: 18.2.0 → 19.0.0 ✅
- MUI upgraded: 5 → 6 ✅
- React Router upgraded: 6 → 7 ✅
- All packages updated and working ✅
- Production build: 995KB bundle ✅
- All containers working ✅

Ready for Phase 3: React Compiler integration

🤖 Generated with [Claude Code](https://claude.ai/code)

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

frontend/src/core/auth/Auth0Provider.tsx

@@ -18,6 +18,7 @@ export const Auth0Provider: React.FC<Auth0ProviderProps> = ({ children }) => {
   const clientId = import.meta.env.VITE_AUTH0_CLIENT_ID;
   const audience = import.meta.env.VITE_AUTH0_AUDIENCE;
 
+
   const onRedirectCallback = (appState?: { returnTo?: string }) => {
     navigate(appState?.returnTo || '/dashboard');
   };