fix(search): address review on the shared result rows

- The rows' narrow layout now switches at a 608px list, not 600px. Below
  769px the page pads 1rem each side, so a 640px screen gives a 608px
  list: exactly the old max-width: 640px media query, where 600px left
  633-640px screens on the wide layout.
- rowContainerGuard.test.ts fails if anything other than HomeView renders
  SchoolRow or SecondarySchoolRow, or if one of HomeView's row lists loses
  its `results` container. Outside one the rows silently keep their wide
  layout on phones. (Checked: HomeView is the only importer today.)
- Picking a pin from the list beside the map now works from the keyboard:
  each row carries a "Show <school> on the map" button, visually hidden
  until focused, with aria-pressed for the selected school. The row itself
  cannot be the button, since it holds links and buttons of its own.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

nextjs-app/__tests__/components/ResultsMapView.test.tsx

@@ -156,10 +156,19 @@ it('builds no list cards on a phone, where the pane is hidden', async () => {
 
 it('draws the list view\'s own row beside the map, with the same content', async () => {
   const { container } = await renderMap();
-  const beside = (container.querySelector('[data-urn="2"]') as HTMLElement).textContent;
+  const beside = container.querySelector('[data-urn="2"] > [class~="row"]')!.textContent;
 
   fireEvent.click(screen.getByRole('button', { name: 'List' }));
   const row = screen.getByRole('link', { name: 'Southmead Primary School' }).closest('[class~="row"]')!;
   expect(row.parentElement?.className).toMatch(/schoolList/);
   expect(row.textContent).toBe(beside);
 });
+
+it('lets a keyboard pick a pin from the list, with a real button', async () => {
+  await renderMap();
+  const show = screen.getByRole('button', { name: 'Show Southmead Primary School on the map' });
+  expect(show).toHaveAttribute('aria-pressed', 'false');
+  fireEvent.click(show);
+  expect(screen.getByTestId('map')).toHaveAttribute('data-selected', '2');
+  expect(show).toHaveAttribute('aria-pressed', 'true');
+});

nextjs-app/__tests__/components/rowContainerGuard.test.ts

@@ -0,0 +1,41 @@
+import fs from 'fs';
+import path from 'path';
+
+/*
+ * SchoolRow and SecondarySchoolRow switch to their narrow layout with a
+ * container query on a `results` container, not a media query, because the
+ * same row fills the phone list and the narrow list beside the desktop map.
+ * Outside a `results` container the query never matches and the row keeps its
+ * wide layout on a phone, a silent regression rather than an error.
+ *
+ * HomeView provides the container on every list it renders the rows into.
+ * Anything else that starts rendering them must do the same; this fails so
+ * that the person adding it reads this first.
+ */
+
+const ROOT = path.join(__dirname, '..', '..');
+const DIRS = ['app', 'components', 'lib'];
+const ROW_IMPORT = /from\s+['"][^'"]*\/(SchoolRow|SecondarySchoolRow)['"]/;
+
+function sources(dir: string): string[] {
+  return fs.readdirSync(dir, { withFileTypes: true }).flatMap((entry) => {
+    const full = path.join(dir, entry.name);
+    if (entry.isDirectory()) return entry.name === 'node_modules' ? [] : sources(full);
+    return /\.tsx?$/.test(entry.name) ? [full] : [];
+  });
+}
+
+it('renders the results rows only where a `results` container is provided', () => {
+  const importers = DIRS.flatMap((d) => sources(path.join(ROOT, d)))
+    .filter((file) => ROW_IMPORT.test(fs.readFileSync(file, 'utf8')))
+    .map((file) => path.relative(ROOT, file));
+  expect(importers).toEqual(['components/HomeView.tsx']);
+});
+
+it('gives each of HomeView\'s row lists the `results` container', () => {
+  const css = fs.readFileSync(path.join(ROOT, 'components', 'HomeView.module.css'), 'utf8');
+  for (const list of ['.schoolList', '.compactList', '.bottomSheet']) {
+    const rule = new RegExp(`\\${list}\\s*\\{[^}]*container:\\s*results\\s*/\\s*inline-size`);
+    expect({ list, provided: rule.test(css) }).toEqual({ list, provided: true });
+  }
+});