chore(app/layout.tsx): fix deprecated viewport nextjs 14

app/layout.tsx

@@ -3,7 +3,7 @@ import "./styles/globals.scss";
 import "./styles/markdown.scss";
 import "./styles/highlight.scss";
 import { getClientConfig } from "./config/client";
-import { type Metadata } from "next";
+import type { Metadata, Viewport } from "next";
 import { SpeedInsights } from "@vercel/speed-insights/next";
 import { getServerSideConfig } from "./config/server";
 import { GoogleTagManager } from "@next/third-parties/google";
@@ -12,21 +12,22 @@ const serverConfig = getServerSideConfig();
 export const metadata: Metadata = {
   title: "NextChat",
   description: "Your personal ChatGPT Chat Bot.",
-  viewport: {
-    width: "device-width",
-    initialScale: 1,
-    maximumScale: 1,
-  },
-  themeColor: [
-    { media: "(prefers-color-scheme: light)", color: "#fafafa" },
-    { media: "(prefers-color-scheme: dark)", color: "#151515" },
-  ],
   appleWebApp: {
     title: "NextChat",
     statusBarStyle: "default",
   },
 };
 
+export const viewport: Viewport = {
+  width: "device-width",
+  initialScale: 1,
+  maximumScale: 1,
+  themeColor: [
+    { media: "(prefers-color-scheme: light)", color: "#fafafa" },
+    { media: "(prefers-color-scheme: dark)", color: "#151515" },
+  ],
+};
+
 export default function RootLayout({
   children,
 }: {