feat(catalog): two-level offers navigation + map auto-centering

- Add fitBounds to CatalogMap for auto-centering on all points
- Add productUuid filter to useCatalogOffers composable
- Create useCatalogProducts composable for products list
- Update offers/index.vue: show products first, then offers by product
- Update offers/map.vue: same two-level navigation
- Add translations for new UI elements

Navigation flow:
/catalog/offers → product selection → offers for that product

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

i18n/locales/en/catalogOffersSection.json

@@ -1,7 +1,8 @@
 {
   "catalogOffersSection": {
     "header": {
-      "title": "Offers"
+      "title": "Offers",
+      "select_product": "Select product"
     },
     "actions": {
       "view_all": "View all"
@@ -11,7 +12,8 @@
       "active": "Active"
     },
     "empty": {
-      "no_offers": "No active offers"
+      "no_offers": "No active offers",
+      "no_products": "No products available"
     }
   }
 }

i18n/locales/ru/catalogOffersSection.json

@@ -1,7 +1,8 @@
 {
   "catalogOffersSection": {
     "header": {
-      "title": "Предложения"
+      "title": "Предложения",
+      "select_product": "Выберите товар"
     },
     "actions": {
       "view_all": "Смотреть все"
@@ -11,7 +12,8 @@
       "active": "Активные"
     },
     "empty": {
-      "no_offers": "Нет активных предложений"
+      "no_offers": "Нет активных предложений",
+      "no_products": "Нет доступных товаров"
     }
   }
 }