ShareDropio/sharedrop ? reverse-engineered prompt

Build me a simple web app like classic ShareDrop, where people can send files directly between devices in the browser without uploading anything to a server first.

I want it to feel like AirDrop, so devices on the same network can see each other automatically, and if they are on different networks I can create a private room link and share it with someone else. Once connected, they should be able to drag and drop files, see nearby devices or avatars, and transfer files securely using peer to peer connections.

Make it work well on modern browsers, especially Chrome, Edge, Firefox, Opera, and Safari. It should be easy to run locally and self host, with clear setup for whatever is needed behind the scenes for device discovery and signaling. If you need current docs for browser support or WebRTC details, look them up online.