feat: nKode React + TypeScript SPA scaffold

- React + Vite + Tailwind CSS v4 + React Router
- Keypad component: 10-digit pad with dot indicators, keyboard support, haptic feel
- Auth pages: Login (email → keypad), Signup (email → method → keypad/key)
- Home page: session info, practice keypad
- Admin dashboard: placeholder stats + user management
- Developer dashboard: OIDC client registration UI placeholder
- WASM client wrapper: lazy loads from /wasm/, falls back to mock client
- TypeScript type declarations for nkode-client-wasm package
- Dark mode with system preference detection
- Auth state management with localStorage persistence + auto-expiry
- Code splitting: lazy-loaded route pages (~236KB main bundle)
- Inter font, clean indigo/slate design system

src/App.tsx

@@ -0,0 +1,41 @@
+import { lazy, Suspense } from 'react';
+import { BrowserRouter, Routes, Route } from 'react-router-dom';
+import { Layout } from '@/components/Layout';
+import { AuthContext, useAuthState } from '@/hooks/useAuth';
+import { ROUTES } from '@/lib/types';
+
+const HomePage = lazy(() => import('@/pages/HomePage').then((m) => ({ default: m.HomePage })));
+const LoginPage = lazy(() => import('@/pages/LoginPage').then((m) => ({ default: m.LoginPage })));
+const SignupPage = lazy(() => import('@/pages/SignupPage').then((m) => ({ default: m.SignupPage })));
+const AdminPage = lazy(() => import('@/pages/AdminPage').then((m) => ({ default: m.AdminPage })));
+const DeveloperPage = lazy(() => import('@/pages/DeveloperPage').then((m) => ({ default: m.DeveloperPage })));
+
+function Loading() {
+  return (
+    <div className="flex items-center justify-center min-h-[50vh]">
+      <div className="w-6 h-6 border-2 border-indigo-500 border-t-transparent rounded-full animate-spin" />
+    </div>
+  );
+}
+
+export default function App() {
+  const auth = useAuthState();
+
+  return (
+    <AuthContext.Provider value={auth}>
+      <BrowserRouter>
+        <Suspense fallback={<Loading />}>
+          <Routes>
+            <Route element={<Layout />}>
+              <Route path={ROUTES.HOME} element={<HomePage />} />
+              <Route path={ROUTES.LOGIN} element={<LoginPage />} />
+              <Route path={ROUTES.SIGNUP} element={<SignupPage />} />
+              <Route path={ROUTES.ADMIN} element={<AdminPage />} />
+              <Route path={ROUTES.DEVELOPER} element={<DeveloperPage />} />
+            </Route>
+          </Routes>
+        </Suspense>
+      </BrowserRouter>
+    </AuthContext.Provider>
+  );
+}