Rushya5/LAN-Chat-2.0 ? reverse-engineered prompt

Build me a lightweight LAN chat app that works completely offline on a local network.

I want people on the same WiFi or Ethernet to open the app in a browser, join quickly, and send real time messages with very low delay. It should support sharing files and images, show a QR code so phones can join easily, and automatically detect the host machine’s local IP so others can connect without any setup. Make the interface modern, responsive, and dark mode by default so it looks good on both desktop and mobile.

Keep it simple, fast, and plug and play, with no database needed. A small in memory chat history is fine, and I’d like a clear history button for the host that wipes the current session for everyone. If you need to check current docs for any libraries or browser behavior, go ahead and look them up online.