[feature request] play against chatgpt

i understand the decision to integrate stockfish, but could you give the option to play chatgpt? this was a neat extension to easily test how well chatgpt plays chess.

Start by inspecting the Python project entry points and the existing Stockfish integration to understand how an opponent is selected. The issue provides no file or test references; done would mean adding a usable option to play against ChatGPT while preserving the existing Stockfish option.

Written by the indexing model from the issue text.