Zcross091/ShonenX ? reverse-engineered prompt

Build me a modern Flutter app for anime and manga fans that lets people discover titles, track what they are watching or reading, and stream or read content in one place.

It should feel fast and polished, with a clean dark focused design, smooth playback, and a good reading experience. I want sign in and syncing with AniList and MyAnimeList so progress, lists, and statuses stay in sync both ways. Please include offline downloads for seasons and manga volumes, plus a way for users to add external content sources through extensions, since the app itself should stay just a frontend client.

Make it work well on Android, Windows, and Linux, and keep the UI responsive and easy to navigate. If you need current implementation details for Flutter or the playback libraries, look up the latest docs online first.