Summary

• parse the optional background_color field into card models with a helper to convert it to RGB values
• paint non-full-frame renders using the configured background colour while updating the docs and sample data
• add unit tests covering both the model defaults and the rendering behaviour (skipping when cairo is unavailable)
• rename manaCost to commandPoints, mapping legacy data and documenting the new JSON schema
• render command points inside a black-bordered shield and extend the model tests to cover the new parsing rules

Testing

• pytest

https://chatgpt.com/codex/tasks/task_e_68e3c63c2b3c832eafdf668c737737e1