fix(a11y): add missing ARIA attributes and landmark regions to docs (#535)

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 #513
Closes #514
Closes #515
Closes #516
Closes #517
Closes #518

Author: berry-13

components/Feedback.tsx

@@ -122,6 +122,7 @@ export function Feedback() {
           <form className="flex flex-col gap-3" onSubmit={submit}>
             <textarea
               autoFocus
+              aria-label="Additional feedback"
               value={message}
               onChange={(e) => setMessage(e.target.value)}
               className="resize-none rounded-lg border border-fd-border bg-fd-secondary p-3 text-sm text-fd-secondary-foreground placeholder:text-fd-muted-foreground focus-visible:outline-none"

package.json

@@ -17,9 +17,9 @@
   "homepage": "https://www.librechat.ai",
   "dependencies": {
     "@glidejs/glide": "^3.6.0",
+    "@hookform/resolvers": "^3.3.4",
     "@mdx-js/loader": "^3.1.1",
     "@mdx-js/react": "^3.1.1",
-    "@hookform/resolvers": "^3.3.4",
     "@radix-ui/react-accordion": "^1.1.2",
     "@radix-ui/react-avatar": "^1.0.4",
     "@radix-ui/react-dialog": "^1.0.5",
@@ -69,8 +69,8 @@
     "@eslint/js": "^9",
     "@next/bundle-analyzer": "^15.1.4",
     "@next/eslint-plugin-next": "^15",
-    "@types/mdx": "^2.0.13",
     "@playwright/test": "^1.58.2",
+    "@types/mdx": "^2.0.13",
     "@types/node": "18.16.0",
     "@types/react": "^18.3.12",
     "autoprefixer": "^10.4.19",
@@ -103,6 +103,9 @@
       "diff": ">=5.2.2",
       "minimatch": ">=3.1.4",
       "serialize-javascript": ">=7.0.3"
+    },
+    "patchedDependencies": {
+      "fumadocs-ui@14.7.7": "patches/fumadocs-ui@14.7.7.patch"
     }
   },
   "nextBundleAnalysis": {