feat(search-frontend): add public landing page, search page with map view, filters, and property cards

- Create (public) route group with landing page (hero, featured listings, district links, stats, CTA)
- Create search page with filter sidebar, list/map/split view modes, URL-synced filters, pagination
- Build ListingMap component with CSS-based marker visualization and popup details
- Build FilterBar with transaction type, property type, city, price range, area, bedrooms filters
- Build PropertyCard and SearchResults components with responsive grid layout
- Update middleware to allow public access to / and /search routes
- Move dashboard home to /dashboard to avoid route conflict
- All content in Vietnamese, mobile responsive

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/app/(dashboard)/layout.tsx

@@ -7,7 +7,7 @@ import { useAuthStore } from '@/lib/auth-store';
 import { Button } from '@/components/ui/button';
 
 const navItems = [
-  { href: '/', label: 'Trang chủ', icon: '🏠' },
+  { href: '/dashboard', label: 'Bảng điều khiển', icon: '🏠' },
   { href: '/listings', label: 'Tin đăng', icon: '📋' },
   { href: '/listings/new', label: 'Đăng tin', icon: '➕' },
 ];