Shubh2-0/Chatterbox ? reverse-engineered prompt

Build me a simple real time chat app called Chatterbox that opens in the browser and lets people join a chat room, send instant messages, and see everyone else’s messages live without refreshing.

I want it to feel smooth and easy to use, with a clean chat screen, a place to type messages, and clear join and leave notifications when people come and go. It should support group chat, so multiple users can be in the same room at once and talk back and forth right away.

Please make it work with Spring Boot and WebSockets, using the usual browser side setup for live messaging. Keep it easy to run locally, and make sure I can start it and open it at localhost:8080. If you need to check current docs online for anything, go ahead.