Function sync_python 

pub fn sync_python(
    dir: &Path,
    name: &str,
    packages: &[&str],
) -> Result<String, String>

Makes or updates the Python environment in dir with uv: writes pyproject.toml first when there is none (with packages, the app’s own needs such as NumPy), then uv sync (the .venv matching uv.lock, made when missing). Returns uv’s report.