fix(search): address review on the results toolbar

- Refold the phone search, and resync its text, when the query changes
  without a submit (back/forward, "Use my location"). The summary and the
  unfolded input could otherwise describe two different searches.
- Cap the "More filters" panel at every width, not only on phones, so an
  open panel scrolls inside the pinned toolbar on a short screen.
- Drop the phone filter row's right-edge fade once it is scrolled to the
  end or does not overflow (the MOBILE.md pattern), and give focus rings
  room inside the scroll clip.

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

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

@@ -102,6 +102,14 @@ describe('the toolbar filters', () => {
   });
 });
 
+describe('the phone filter row', () => {
+  it('drops its "more this way" fade when nothing is left to scroll', () => {
+    render(<FilterBar filters={filters} />);
+    // jsdom lays nothing out, so the row reads as not overflowing at all.
+    expect(screen.getByRole('group', { name: 'Filters' }).className).toMatch(/controlsAtEnd/);
+  });
+});
+
 describe('the folded search', () => {
   it('summarises the search and unfolds on tap', () => {
     render(<FilterBar filters={filters} />);
@@ -119,6 +127,22 @@ describe('the folded search', () => {
     expect(screen.getByRole('button', { name: /Edit search/ })).toBeInTheDocument();
   });
 
+  it('refolds and shows the new text when the search changes some other way', () => {
+    const view = render(<FilterBar filters={filters} />);
+    fireEvent.click(screen.getByRole('button', { name: /Edit search/ }));
+    fireEvent.change(screen.getByRole('searchbox', { name: 'School name or postcode' }),
+      { target: { value: 'half-typed' } });
+
+    // Back button: the URL changes under the component, nothing is submitted.
+    params = new URLSearchParams('postcode=SW170AA&radius=3');
+    view.rerender(<FilterBar filters={filters} />);
+
+    expect(screen.getByRole('button', { name: 'Edit search: SW170AA, within 3 miles' }))
+      .toBeInTheDocument();
+    expect(screen.getByRole('searchbox', { name: 'School name or postcode' }))
+      .toHaveValue('SW170AA');
+  });
+
   it('never appears in the hero, or before anything has been searched', () => {
     const { unmount } = render(<FilterBar filters={filters} isHero />);
     expect(screen.queryByRole('button', { name: /Edit search/ })).not.toBeInTheDocument();