singerdmx/flutter-quill ? reverse-engineered prompt

Build me a Flutter app that shows a rich text editor like the one in the README.

I want a clean writing screen with a formatting toolbar for the usual stuff like bold, italic, underline, lists, headings, links, and image or embed support if that fits. The editor should work on mobile, web, and desktop, and I should be able to type, edit, and see the formatting right away. Please include a simple example page that lets me save the content and load it back again, ideally using the document data format this package uses. It would also be great if the app supports read only mode and a basic way to switch it on and off.

Make it feel like a real app, not just a demo widget. Keep the UI simple and polished, and if you need to check current docs online for the best setup, go ahead and do that.