bldng1337/dion ? reverse-engineered prompt

Build me a Flutter app for Windows and Android that works like a media reader and player in one place.

I want users to be able to sync a library, browse their collections by categories, and manage downloads. It should support novels, comics or manga, video, and audio, with a clean interface that feels good on both desktop and mobile. Make it easy to open an item, see its details, continue reading or watching, and jump back into recent activity.

Please include the main screens I’d expect, like a library view, an item detail page, a downloads area, settings, and some kind of activity or history view. Keep it extensible so it could grow to support more media types later. If you need to check current Flutter docs or best practices while building it, go ahead and look them up online.