smritisingh110/ExpenseTracker ? reverse-engineered prompt

Build me a simple Java desktop app for tracking daily expenses with a clean Swing interface.

I want to be able to add an expense with basic details, then see all the expenses I’ve entered in the app. It should feel lightweight and easy to use, with a friendly GUI and simple controls for adding and managing items. Please keep it beginner friendly and make sure it runs from a single Java file if possible, using standard Java and Swing only.

If anything is unclear, make reasonable choices and keep the app straightforward. Also, please include the code so I can compile it with javac and run it directly, and look up current docs online if you need to confirm any Swing details.