docs: render route anatomy with a color-coded, linkable component

Replace the anatomy breakdown table with a <RouteAnatomy/> component
(@site/src/components/route-anatomy, added in the docs site) that color-codes
each part of the example route and links it to its section, so readers can hover
or click the method, path, parameter, and handler directly in the example. A
prose sentence keeps the same mapping as an accessible text fallback.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>