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/catalog/SuppliersBreadcrumbs.vue

@@ -30,7 +30,7 @@ const breadcrumbs = computed(() => {
   // Suppliers list
   crumbs.push({
     label: t('breadcrumbs.suppliers', 'Suppliers'),
-    to: localePath('/catalog/suppliers')
+    to: localePath('/catalog?select=supplier')
   })
 
   // Supplier
@@ -38,7 +38,7 @@ const breadcrumbs = computed(() => {
     const hasNext = props.productId
     crumbs.push({
       label: props.supplierName || `#${props.supplierId.slice(0, 8)}...`,
-      to: hasNext ? localePath(`/catalog/suppliers/${props.supplierId}`) : undefined
+      to: hasNext ? localePath(`/catalog?supplier=${props.supplierId}`) : undefined
     })
   }
 
@@ -47,7 +47,7 @@ const breadcrumbs = computed(() => {
     const hasNext = props.hubId
     crumbs.push({
       label: props.productName || `#${props.productId.slice(0, 8)}...`,
-      to: hasNext ? localePath(`/catalog/suppliers/${props.supplierId}/${props.productId}`) : undefined
+      to: hasNext ? localePath(`/catalog?supplier=${props.supplierId}&product=${props.productId}`) : undefined
     })
   }