feat(web): redesign homepage with solutions showcase + tabbed featured section

- Add "Giải pháp GoodGo" section after hero with 4 feature cards
  linking to the platform's core products: Dự án, Khu công nghiệp,
  Chuyển nhượng, Định giá BĐS.
- Convert "Tin đăng nổi bật" from residential-only 3-column grid into a
  tabbed section with one tab per core feature. Items render as a
  vertical list of horizontal cards (image left, title/location/meta
  right, price + arrow). Valuation tab shows a highlight CTA since it's
  a tool, not a listing type.
- Remove "Khu vực nổi bật" district quick-links block (didn't fit the
  platform's multi-product positioning).
- Fix invisible "Tìm kiếm ngay" button on CTA section — outline variant
  defaulted to bg-background (white) masking text-primary-foreground
  (white) on the primary background.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/app/[locale]/(public)/__tests__/landing.spec.tsx

@@ -80,15 +80,6 @@ describe('LandingPage', () => {
     });
   });
 
-  it('renders districts section', async () => {
-    render(<LandingPage />);
-
-    await waitFor(() => {
-      expect(screen.getByText('Quận 1')).toBeInTheDocument();
-      expect(screen.getByText('Quận 7')).toBeInTheDocument();
-    });
-  });
-
   it('renders stats section', async () => {
     render(<LandingPage />);