Patch fumadocs-ui to fix accessibility issues reported by amberhinds,
plus additional issues found via WCAG 2.1 audit:
Reported issues:
- #513: Add aria-label to docs navigation toggle button
- #514: Add aria-haspopup="dialog" and aria-label to search buttons
- #515: Fix close search button accessible name to include visible text
- #516: Add role="status" live region for screen reader search announcements
- #517: Change search suggestions from <button> to <a> links with role="option"
- #518: Add nav landmarks for sidebar, breadcrumbs, TOC, and pagination
Additional fixes found via audit:
- Theme toggle button: add aria-label="Toggle theme" (WCAG 4.1.2)
- Sidebar <aside>: add aria-label="Docs sidebar" (WCAG 4.1.2)
- Collapse sidebar button: dynamic label based on state (WCAG 4.1.2)
- Heading anchor link icons: add peer-focus-visible:opacity-100 (WCAG 2.4.7)
- Breadcrumbs: use <ol>/<li> structure, aria-hidden on separator SVGs (WCAG 1.3.1)
- Feedback textarea: add aria-label (WCAG 4.1.2)
Closes#513Closes#514Closes#515Closes#516Closes#517Closes#518