- Replace inline BrowserRouter with createBrowserRouter and lazy-loaded pages
- Add Redux store with auth-slice (token management) and redux-persist
- Create RequireAuth guard using Redux state via isAuthenticated selector
- Wire Layout logout to dispatch setToken("") clearing persisted auth
- Add ErrorPage component for route error handling
- Add EmptyLayout for unauthenticated pages
- Add VITE_REDUX_STORAGE env var for storage selection
