feat(a11y): add skip link for improved navigation accessibility

apps/backoffice/src/app/layouts/BackofficeLayout.tsx

@@ -8,6 +8,7 @@ import { AppHeader, AppSidebar } from '@ema-platform/ui';
 import type { NavItem, NavSection } from '@ema-platform/ui';
 import { notify } from '@ema-platform/ui';
 import { AppTopNav, filterByPermissions } from '@ema-platform/ui';
+import { SkipLink, MAIN_CONTENT_ID } from '@ema-platform/ui';
 import { baseApi, useGetQueueCountsQuery } from '@ema-platform/api';
 import { usePermissions } from '@ema-platform/auth';
 import { SUPPORTED_LANGUAGES } from '../i18n/config';
@@ -143,6 +144,10 @@ export function BackofficeLayout() {
   const isSidebar = layoutMode === "sidebar";
 
   return (
+    <>
+      {/* First focusable element on the page, so a keyboard user can bypass
+          the 20-plus nav items instead of tabbing through them every time. */}
+      <SkipLink />
     <AppShell
       header={{ height: isSidebar ? 74 : HEADER_HEIGHT }}
       navbar={
@@ -226,7 +231,7 @@ export function BackofficeLayout() {
         </AppShell.Navbar>
       )}
 
-      <AppShell.Main>
+      <AppShell.Main id={MAIN_CONTENT_ID}>
         <div key={location.pathname} className="ema-page-enter">
           <Outlet />
         </div>
@@ -263,5 +268,6 @@ export function BackofficeLayout() {
         </Drawer>
       )}
     </AppShell>
+    </>
   );
 }