programmeraj2011/zombie_chat ? reverse-engineered prompt

Build me a simple local network chat app where people on the same Wi Fi can open a webpage, pick a handle once, and start sending messages right away without needing the internet.

I want it to feel a little retro and hacker themed, work nicely on phones and desktop, and keep the handle saved in the browser so users do not have to type it every time. Messages should refresh automatically every few seconds, and people should be able to upload and share images from the chat too. Keep it lightweight and easy to run locally with Python, and store the chat history in memory for now, since it is just for small local use. If you need to check current docs online while building it, go ahead. Make sure it runs on the local server and can be opened from other devices on the same network too.