Implement unified catalog search with token-based filtering

- 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

app/components/search/GlobalSearchBar.vue

@@ -112,18 +112,18 @@ const handleSearch = () => {
     query.quantity = String(quantity.value)
   }
 
-  // Navigate to offers flow
+  // Navigate to unified catalog
   if (productUuid.value && locationUuid.value) {
     // Both product and hub selected -> show offers
     router.push({
-      path: localePath(`/catalog/offers/${productUuid.value}/${locationUuid.value}`),
-      query
+      path: localePath('/catalog'),
+      query: { product: productUuid.value, hub: locationUuid.value, ...query }
     })
   } else if (productUuid.value) {
-    // Only product selected -> select hub
+    // Only product selected -> show hubs for product
     router.push({
-      path: localePath(`/catalog/offers/${productUuid.value}`),
-      query
+      path: localePath('/catalog'),
+      query: { product: productUuid.value, ...query }
     })
   }