feat: implement TASK-WP1-04 admin security

apps/web/src/main.tsx

@@ -2,6 +2,7 @@ import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
 
 import { registerPublicAssetServiceWorker } from "./public-asset-cache.js";
+import { AdminAuthPage } from "./admin-auth.js";
 import { UserAuthPage } from "./user-auth.js";
 
 const root = document.getElementById("root");
@@ -18,9 +19,12 @@ let authRevision = 0;
 
 function renderAuthenticationEntry() {
   authRevision += 1;
+  const authenticationPage = window.location.pathname.startsWith("/admin")
+    ? <AdminAuthPage key={authRevision} />
+    : <UserAuthPage key={authRevision} />;
   appRoot.render(
     <StrictMode>
-      <UserAuthPage key={authRevision} />
+      {authenticationPage}
     </StrictMode>,
   );
 }