Style Books Editor Improvements

The Style Book Editor has been improved to make managing design tokens simpler and more intuitive, with a clearer approach to editing colours and improved overall usability.

Key Benefits:

Faster updates: Edit colour tokens quickly through a single, clear interaction point.
Easier to use: Fewer competing controls reduce confusion and make the editor more approachable.
Consistent experience: Interaction patterns now align with the Page Editor, improving learnability.
Built for growth: A stronger foundation to support future design token capabilities and enhancements.
Fewer errors: Improved interactions reduce friction and mistakes when updating styles.