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/navigation/SubNavigation.vue

@@ -25,9 +25,9 @@ const { t } = useI18n()
 
 const sectionItems = computed(() => ({
   catalog: [
-    { label: 'Предложения', path: '/catalog/offers' },
-    { label: t('cabinetNav.suppliers'), path: '/catalog/suppliers' },
-    { label: t('cabinetNav.hubs'), path: '/catalog/hubs' },
+    { label: 'Предложения', path: '/catalog?select=product' },
+    { label: t('cabinetNav.suppliers'), path: '/catalog?select=supplier' },
+    { label: t('cabinetNav.hubs'), path: '/catalog?select=hub' },
   ],
   orders: [
     { label: t('cabinetNav.orders'), path: '/clientarea/orders' },