KPN2413/shop-flow ? reverse-engineered prompt

Build me a simple shopping app called Shop Flow that helps people browse products, add things to a cart, and go through a clean checkout flow.

I want it to feel modern and easy to use on mobile and desktop, with a polished homepage, product listings, product detail pages, cart, and a basic checkout screen. If it makes sense, use Supabase for data and user sign in so the app can save products and user info. Make the design clean and friendly, with a nice shopping focused layout and a few helpful empty states and loading states.

Please set it up so I can run it locally right away, and make the code easy to understand and extend later. If you need current docs for any library or integration, look them up online.