Sunset React wrappers

[daneah]

The problem

React 19 supports web components natively. We should avoid expending further effort in supporting the React wrapper and the React Storybook, as it duplicates that effort and can create divergence.

The solution

• Remove React wrapper
• Remove React Storybook
• Remove React dependencies (unless somehow needed for Gatsby build)
• Streamline Storybook config to a single Storybook

This obviates the need for:

• #855
• #854
• #812
• #706