- Add useCatalogSearch composable for managing unified search state
- Add UnifiedSearchBar component with token chips for filters
- Add CatalogHero component for empty/landing state
- Create grid components for each display mode:
- CatalogGridProducts, CatalogGridSuppliers, CatalogGridHubs
- CatalogGridHubsForProduct, CatalogGridProductsFromSupplier
- CatalogGridProductsInHub, CatalogGridOffers
- Add unified catalog page at /catalog with query params
- Remove SubNavigation from catalog section (kept for other sections)
- Update all links to use new unified catalog paths
- Delete old nested catalog pages (offers/suppliers/hubs flows)
- Add i18n translations for catalog section
