earthcomfy/lets-chat ? reverse-engineered prompt

Build me a real time chat app called Let’s Chat.

I want people to be able to sign up and log in with email and password, then set up their profile with a display name and avatar. Let users make chat rooms, join them, and send messages that update live for everyone in the room. Please include online status, search for people or chats, an emoji picker, and a dark mode toggle.

Use a clean modern interface that feels nice on desktop and mobile, with Tailwind styling on the front end. Use Firebase for authentication, MongoDB for storing rooms and messages, and Socket.io so the chat feels instant. If you need to check current docs online for anything, go ahead.

Make it feel polished and ready to run locally, with the frontend and backend working together, and set it up so I can plug in my own Firebase and database settings easily.