Agentic retry for python syntax errors

[jeremyfowers]

It is fairly common for game generation to fail due to a minor Python syntax error.

We could try to get past this with a control flow like:

1. Attempt to generate the game based on the users prompt
2. If there's a failure, get the stack trace from the pygame subprocess stdout/stderr
3. Invoke the LLM again with system message "The following Python code has an error. Output a single Python code block that fixes the error. Make no other adjustments. Error: ERROR; Code: CODE."
4. Replace the existing game in the library with the new game that was generated.