♿️(frontend) focus docs list title after filter navigation

Explain focus shift to match skip-to-content behavior.

hook useRouteChangeCompleteFocus

Positionne the focus on the first target or main element after a route change.

src/frontend/apps/e2e/__tests__/app-impress/left-panel.spec.ts

@@ -18,6 +18,20 @@ test.describe('Left panel desktop', () => {
     await expect(page.getByTestId('home-button')).toBeVisible();
   });
 
+  test('focuses main content after switching the docs filter', async ({
+    page,
+  }) => {
+    await page.goto('/');
+
+    const myDocsLink = page.getByRole('link', { name: 'My docs' });
+    await myDocsLink.focus();
+    await page.keyboard.press('Enter');
+    await expect(page).toHaveURL(/target=my_docs/);
+
+    const mainContent = page.locator('main#mainContent');
+    await expect(mainContent).toBeFocused();
+  });
+
   test('checks resize handle is present and functional on document page', async ({
     page,
     browserName,

src/frontend/apps/impress/src/core/AppProvider.tsx

@@ -9,6 +9,7 @@ import { useEffect } from 'react';
 
 import { useCunninghamTheme } from '@/cunningham';
 import { Auth, KEY_AUTH, setAuthUrl } from '@/features/auth';
+import { useRouteChangeCompleteFocus } from '@/hooks/useRouteChangeCompleteFocus';
 import { useResponsiveStore } from '@/stores/';
 
 import { ConfigProvider } from './config/';
@@ -51,6 +52,7 @@ const queryClient = new QueryClient({
 export function AppProvider({ children }: { children: React.ReactNode }) {
   const { theme } = useCunninghamTheme();
   const { replace } = useRouter();
+  useRouteChangeCompleteFocus();
 
   const initializeResizeListener = useResponsiveStore(
     (state) => state.initializeResizeListener,

src/frontend/apps/impress/src/features/docs/docs-grid/components/DocsGrid.tsx

@@ -237,7 +237,7 @@ const DocGridTitleBar = ({
     >
       <Box $direction="row" $gap="xs" $align="center">
         {icon}
-        <Text as="h2" $size="h4" $margin="none">
+        <Text as="h2" $size="h4" $margin="none" tabIndex={-1}>
           {title}
         </Text>
       </Box>

src/frontend/apps/impress/src/features/left-panel/components/LefPanelTargetFilters.tsx

@@ -70,7 +70,9 @@ export const LeftPanelTargetFilters = () => {
             href={href}
             aria-label={query.label}
             aria-current={isActive ? 'page' : undefined}
-            onClick={handleClick}
+            onClick={() => {
+              handleClick();
+            }}
             $css={css`
               display: flex;
               align-items: center;

src/frontend/apps/impress/src/hooks/useRouteChangeCompleteFocus.tsx

@@ -0,0 +1,38 @@
+import { useRouter } from 'next/router';
+import { useEffect } from 'react';
+
+import { MAIN_LAYOUT_ID } from '@/layouts/conf';
+
+export const useRouteChangeCompleteFocus = () => {
+  const router = useRouter();
+
+  useEffect(() => {
+    const handleRouteChangeComplete = () => {
+      requestAnimationFrame(() => {
+        const mainContent =
+          document.getElementById(MAIN_LAYOUT_ID) ??
+          document.getElementsByTagName('main')[0];
+
+        if (!mainContent) {
+          return;
+        }
+
+        const firstHeading = mainContent.querySelector('h1, h2, h3');
+        const prefersReducedMotion = window.matchMedia(
+          '(prefers-reduced-motion: reduce)',
+        ).matches;
+
+        (mainContent as HTMLElement | null)?.focus({ preventScroll: true });
+        (firstHeading ?? mainContent)?.scrollIntoView({
+          behavior: prefersReducedMotion ? 'auto' : 'smooth',
+          block: 'start',
+        });
+      });
+    };
+
+    router.events.on('routeChangeComplete', handleRouteChangeComplete);
+    return () => {
+      router.events.off('routeChangeComplete', handleRouteChangeComplete);
+    };
+  }, [router.events]);
+};