isagix-16/splite ? reverse-engineered prompt

Build me a full expense splitting app where people can sign up, log in, create groups, add shared expenses, and see who owes who. I want a clean modern interface with a dashboard, a way to invite or manage group members, and simple screens for adding bills, splitting them evenly or by custom amounts, and tracking balances over time.

Make it feel polished and easy to use on desktop and mobile, with nice reusable UI components and a good looking layout. Please include authentication, protected pages, and a backend that stores users, groups, expenses, and settlements properly. If you need current docs for any tools or libraries, look them up online first.

I also want the app to be ready to run locally with clear setup, and the main flow should work end to end, from creating a group to seeing the final balance summary.