feat: add admin hardware management page with CRUD

- Device list fetched from /api/hardware/stats
- Create/edit devices via modal form
- Delete with confirmation dialog
- Uses existing hardware CRUD API endpoints

app/(admin)/admin/hardware/page.tsx

@@ -0,0 +1,10 @@
+import type { Metadata } from "next"
+import { HardwareClient } from "./hardware-client"
+
+export const metadata: Metadata = {
+  title: "Hardware",
+}
+
+export default function HardwarePage() {
+  return <HardwareClient />
+}