Canvas navigation components

Build navigation that fits Canvas: reusable names, clear props (variant, menuName) and slots (logo, utilities, mega-menu regions), correct data source (Drupal menu vs breadcrumb context vs static), and accessible markup.

This skill stacks on:

1. canvas-design-decomposition — regions, tree, prop/slot sketch, reuse-first naming before code.
2. canvas-data-fetching — SWR, JsonApiClient, menu resource pattern, Workbench rules.