alzabirr/snap- — reverse-engineered prompt

Build me a clean Flutter app called Snap using this starter project. The README is just the default Flutter setup, so keep the scope simple and turn it into a polished app foundation instead of trying to guess a big product.

Replace the default counter screen with a modern home screen that feels ready to customize, with a clear app title, a short welcome message, and a few simple cards or sections showing what Snap could do later. Add a basic settings or about screen, simple navigation, light and dark mode support, and make sure it looks good on phone, web, and desktop sizes.

Please keep the code organized and easy for a beginner to understand. Use sensible Flutter patterns, clean widgets, and readable names. Remove any unused starter code. Make sure it runs without errors and include a short note in the README explaining how to run it. Look up current Flutter docs online if you need to.