sanderland/katrain ? reverse-engineered prompt

Build me a desktop app for playing and reviewing Go games with AI help from KataGo.

I want a clean app where I can load an SGF, step through the game, and quickly see the biggest mistakes and how many points they cost. It should also let me play against the AI with instant feedback on each move, including an option to undo or retry when I make a bad move. Please include a teaching mode where the app can automatically analyze my move and take back clearly bad moves. It would be great if the app can generate focused review files that highlight the most important mistakes, and let me choose different strengths or styles of AI so I can practice against weaker opponents too.

Make it feel polished and easy to use, with a board, move list, analysis panel, and basic settings for the engine and appearance. If you need to look up current docs for KataGo or any install details, feel free to do that.