fix: added energy-management

energy-management/frontend/src/App.tsx

@@ -0,0 +1,23 @@
+import { useState } from "react";
+import { Dashboard } from "./Dashboard";
+import { Devices } from "./Devices";
+
+type Tab = "dashboard" | "devices";
+
+export function App() {
+  const [tab, setTab] = useState<Tab>("dashboard");
+
+  return (
+    <div className="app">
+      <nav className="tabs">
+        <button className={tab === "dashboard" ? "active" : ""} onClick={() => setTab("dashboard")}>
+          Dashboard
+        </button>
+        <button className={tab === "devices" ? "active" : ""} onClick={() => setTab("devices")}>
+          Devices
+        </button>
+      </nav>
+      {tab === "dashboard" ? <Dashboard /> : <Devices />}
+    </div>
+  );
+}