Refactor catalog to use coordinate-based GraphQL endpoints

Replace entity-specific queries (GetProductsNearHub, GetOffersByHub, GetHubsForProduct, GetSuppliersForProduct) with unified coordinate-based endpoints (NearestHubs, NearestOffers, NearestSuppliers, RouteToCoordinate). This simplifies backend architecture from 18 to 8 core endpoints while maintaining identical UI/UX behavior.

All composables and pages now use coordinates + client-side grouping instead of specialized backend queries. For global product filtering, uses center point (0,0) with 20000km radius.

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

app/composables/useCatalogHubs.ts

@@ -1,4 +1,4 @@
-import { GetNodesDocument, GetHubCountriesDocument, GetHubsForProductDocument } from '~/composables/graphql/public/geo-generated'
+import { GetNodesDocument, GetHubCountriesDocument, NearestHubsDocument } from '~/composables/graphql/public/geo-generated'
 
 const PAGE_SIZE = 24
 
@@ -52,15 +52,22 @@ export function useCatalogHubs() {
   const fetchPage = async (offset: number, replace = false) => {
     if (replace) isLoading.value = true
     try {
-      // If filtering by product, use specialized query
+      // If filtering by product, use nearestHubs with global search
+      // (center point 0,0 with very large radius to cover entire globe)
       if (filterProductUuid.value) {
         const data = await execute(
-          GetHubsForProductDocument,
-          { productUuid: filterProductUuid.value },
+          NearestHubsDocument,
+          {
+            lat: 0,
+            lon: 0,
+            radius: 20000, // 20000 km radius covers entire Earth
+            productUuid: filterProductUuid.value,
+            limit: 500 // Increased limit for global search
+          },
           'public',
           'geo'
         )
-        const next = data?.hubsForProduct || []
+        const next = data?.nearestHubs || []
         items.value = next
         total.value = next.length
         isInitialized.value = true