amitmohite078-bot/LinkUp ? reverse-engineered prompt

Build me a simple full stack app called LinkUp with a Java backend and a frontend.

I want it to feel clean and modern, with a landing page, a basic sign up and login flow, and a main dashboard where people can add, edit, and view the links or items they save and share. Make the interface easy to use on desktop and mobile, and connect the frontend to the backend so the data actually works end to end. Keep the setup straightforward so I can run it locally without a lot of extra work. If you need to check current docs for anything along the way, please do that.