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/useCatalogSuppliers.ts

@@ -1,5 +1,5 @@
 import { GetSupplierProfilesDocument } from '~/composables/graphql/public/exchange-generated'
-import { GetSuppliersForProductDocument } from '~/composables/graphql/public/geo-generated'
+import { NearestSuppliersDocument } from '~/composables/graphql/public/geo-generated'
 
 const PAGE_SIZE = 24
 
@@ -24,29 +24,22 @@ export function useCatalogSuppliers() {
   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 nearestSuppliers with global search
+      // (center point 0,0 with very large radius to cover entire globe)
       if (filterProductUuid.value) {
         const data = await execute(
-          GetSuppliersForProductDocument,
-          { productUuid: filterProductUuid.value },
+          NearestSuppliersDocument,
+          {
+            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 supplierUuids = (data?.suppliersForProduct || []).map(s => s?.uuid).filter(Boolean)
-        // Fetch full profiles for these suppliers
-        if (supplierUuids.length > 0) {
-          const profilesData = await execute(
-            GetSupplierProfilesDocument,
-            { limit: supplierUuids.length, offset: 0 },
-            'public',
-            'exchange'
-          )
-          // Filter to only include suppliers that match the product filter
-          const allProfiles = profilesData?.getSupplierProfiles || []
-          items.value = allProfiles.filter(p => supplierUuids.includes(p.uuid))
-        } else {
-          items.value = []
-        }
+        items.value = data?.nearestSuppliers || []
         total.value = items.value.length
         isInitialized.value = true
         return