Summary

This PR polishes the work contributed in #1349. Mostly implementation consistency with respect to other CAMs and the reference publication. The sUCS colourspace was split in two so that it returns now rectangular coordinates and two extra definitions are responsible for the transformation to polar coordinates. The chromatic adaptation transform has been extracted to its own definition: colour.chromatic_adaptation_Li2025.

Preflight

Code Style and Quality

• Unit tests have been implemented and passed.
• Pyright static checking has been run and passed.
• Pre-commit hooks have been run and passed.
• New transformations have been added to the Automatic Colour Conversion Graph.
• New transformations have been exported to the relevant namespaces, e.g. colour, colour.models.

Documentation

• New features are documented along with examples if relevant.
• The documentation is Sphinx and numpydoc compliant.