jonataslaw/getx ? reverse-engineered prompt

Build me a Flutter package and sample app that makes it really easy to manage app state, navigate between screens, and handle dependency injection without needing context.

I want the app to show how to open screens, snackbars, dialogs, and bottom sheets from anywhere, plus a simple counter or todo example that proves the state updates cleanly. Add support for reactive updates, basic controller style organization, and easy service registration so I can keep business logic out of the UI. Include a few examples of routing, a reusable page structure, and a simple way to switch languages with translations. If it fits naturally, also show how to make a network request with a clean helper and how to set up a light and dark theme toggle.

Please make it feel polished and easy to understand, with a working example I can run right away. Look up current Flutter and Dart docs online if you need to.