feat: Migrate play notebook to Python script and update dependencies

- Removed the `play.ipynb` notebook and created a new `playground.py` script to enhance code organization and maintainability.
- Updated `pyproject.toml` to include `jupytext` for Jupyter notebook conversion support.
- Added instructions in `README.md` for converting notebooks using Jupytext.
- Enhanced the `uv.lock` file to reflect the new dependency on Jupytext.

pyproject.toml

@@ -11,6 +11,7 @@ dependencies = [
     "cvxopt>=1.3.2",
     "jax[cuda12]>=0.5.1",
     "jaxtyping>=0.2.38",
+    "jupytext>=1.17.0",
     "matplotlib>=3.10.1",
     "opencv-python-headless>=4.11.0.86",
     "orjson>=3.10.15",