refactor: serve static frontend with Go APIs

app/usage/page.tsx

@@ -1,10 +1,13 @@
+"use client";
+
 import { UsageManager } from "@/components/usage-manager";
-import { hasSuperAdminAccess } from "@/lib/auth/permissions";
-import { requireAdminSession } from "@/lib/server/auth/current-user";
+import { BrowserAuthGuard, useBrowserAuth } from "@/components/browser-auth";
 
-export const dynamic = "force-dynamic";
-
-export default async function UsagePage() {
-  const session = await requireAdminSession();
-  return <UsageManager isSuperAdmin={hasSuperAdminAccess(session.user)} />;
+export default function UsagePage() {
+  return <BrowserAuthGuard role="admin"><UsageContent /></BrowserAuthGuard>;
+}
+
+function UsageContent() {
+  const { isSuperAdmin } = useBrowserAuth();
+  return <UsageManager isSuperAdmin={isSuperAdmin} />;
 }