javascriptbear/todo_react_app ? reverse-engineered prompt

Build me a simple todo list app in React styled with Mantine UI.

I want a clean page where I can add new tasks, see them in a list, and delete ones I am done with. Please make the app remember my todos in local storage so they are still there when I come back later, and load them automatically when the page opens. Also add a light and dark mode toggle that changes the look of the app nicely.

Keep it simple, polished, and easy to use on desktop and mobile. Use sensible spacing, good typography, and make the main todo area feel like a small finished product instead of a bare demo. If you need to check current Mantine or React docs online, go ahead.