InlitX/streak ? reverse-engineered prompt

Build me a calm, private habit tracker for Android in Flutter that works fully offline and has no ads or tracking.

I want people to be able to create habits, tap once to log them, and see their progress in a simple but beautiful way with streaks, a calendar style activity grid, stats, and charts. It should support normal habits, habits to avoid, and amount based habits with goals, plus reminders, notes for a day, and the ability to fill in past days. Add a focus timer for habits that need one, with simple session tracking and a few nice sound and clock style options. Make it feel polished and easy to customize with light and dark themes, a few visual styles, and widgets or quick actions for logging fast.

Keep everything stored on the device, and make the app feel minimal, fast, and friendly. If you need current Flutter or Android guidance, look up the latest docs online.