test(chat): enable resizes-content keyboard experiment

src/app/chat/layout.tsx

@@ -1,7 +1,12 @@
+import type { Viewport } from "next";
 import type { ReactNode } from "react";
 
 import { ChatRouteProviders } from "@/providers/chat-route-providers";
 
+export const viewport: Viewport = {
+  interactiveWidget: "resizes-content",
+};
+
 export default function ChatLayout({ children }: { children: ReactNode }) {
   return <ChatRouteProviders>{children}</ChatRouteProviders>;
 }