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>

app/composables/useCatalogProducts.ts

@@ -0,0 +1,41 @@
+import { GetProductsDocument } from '~/composables/graphql/public/exchange-generated'
+
+// Shared state
+const items = ref<any[]>([])
+const isLoading = ref(false)
+const isInitialized = ref(false)
+
+export function useCatalogProducts() {
+  const { execute } = useGraphQL()
+
+  const fetchProducts = async () => {
+    if (isLoading.value) return
+    isLoading.value = true
+    try {
+      const data = await execute(
+        GetProductsDocument,
+        {},
+        'public',
+        'exchange'
+      )
+      items.value = data?.getProducts || []
+      isInitialized.value = true
+    } finally {
+      isLoading.value = false
+    }
+  }
+
+  const init = async () => {
+    if (!isInitialized.value && items.value.length === 0) {
+      await fetchProducts()
+    }
+  }
+
+  return {
+    items,
+    isLoading,
+    isInitialized,
+    fetchProducts,
+    init
+  }
+}