GNOME/gnome-chess ? reverse-engineered prompt

Build me a simple GNOME chess game that looks and feels like a normal desktop app.

I want a 2D chess board where two people can play against each other, or one person can play against the computer. If there are any chess engines already installed on the system, the app should try to find them and let me use one for the computer opponent.

Please make it usable, clean, and consistent with GNOME style, with a nice board, legal moves, game start and reset, and basic game status like whose turn it is and when someone wins or draws. If there are existing docs or Flatpak build instructions in the repo, follow those so the app can be built and run easily. Look up current docs online if you need to, and make sure it works well as a desktop app.