feat(web): TanStack Query hooks + session-guarded routes

Installs @tanstack/react-query and react-router-dom; adds typed query
hooks (useMe, useObjectsPage, useObject, useFieldDefinitions, useLogin,
useLogout), a QueryClient+MemoryRouter test render helper, and
RequireAuth — a layout route that blocks unauthenticated access and
redirects to /login. All 7 tests pass, typecheck/lint/build clean.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/auth/require-auth.tsx

@@ -0,0 +1,13 @@
+import { Navigate, Outlet } from "react-router-dom";
+
+import { useMe } from "../api/queries";
+
+export function RequireAuth() {
+  const { data: user, isLoading } = useMe();
+
+  if (isLoading) return <div role="status" aria-label="loading" />;
+
+  if (!user) return <Navigate to="/login" replace />;
+
+  return <Outlet />;
+}