- Add Remix‑style data loading and mutation APIs (loaders, actions, defer/Await, <Form>, useFetcher) across all routers.
- Introduce new router creation helpers (createMemoryRouter, createBrowserRouter, createHashRouter) and rendering via <RouterProvider>, plus navigation improvements like <Link relative="path">, <ScrollRestoration>, and errorElement support.
- Fix path resolution (trailing‑slash agnostic), scoped useLocation inside <Routes>, and ensure <Link replace> prop is respected.