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/pages/catalog/hubs/[id]/index.vue

@@ -43,7 +43,7 @@
 </template>
 
 <script setup lang="ts">
-import { GetNodeConnectionsDocument, GetProductsNearHubDocument } from '~/composables/graphql/public/geo-generated'
+import { GetNodeConnectionsDocument, NearestOffersDocument } from '~/composables/graphql/public/geo-generated'
 
 definePageMeta({
   layout: 'topnav'
@@ -122,17 +122,45 @@ const getMockPriceHistory = (uuid: string): number[] => {
 
 // Initial load
 try {
-  const [{ data: connectionsData }, { data: productsData }] = await Promise.all([
-    useServerQuery('hub-connections', GetNodeConnectionsDocument, { uuid: hubId.value }, 'public', 'geo'),
-    useServerQuery('products-near-hub', GetProductsNearHubDocument, { hubUuid: hubId.value, radiusKm: 500 }, 'public', 'geo')
-  ])
+  // First load hub connections to get coordinates
+  const { data: connectionsData } = await useServerQuery(
+    'hub-connections',
+    GetNodeConnectionsDocument,
+    { uuid: hubId.value },
+    'public',
+    'geo'
+  )
 
   hub.value = connectionsData.value?.nodeConnections?.hub || null
 
-  // Get products near this hub (from geo)
-  products.value = (productsData.value?.productsNearHub || [])
-    .filter((p): p is { uuid: string; name?: string | null } => p !== null && !!p.uuid)
-    .map(p => ({ uuid: p.uuid!, name: p.name || '' }))
+  // Load offers near hub and group by product
+  if (hub.value?.latitude && hub.value?.longitude) {
+    const { data: offersData } = await useServerQuery(
+      'offers-near-hub',
+      NearestOffersDocument,
+      {
+        lat: hub.value.latitude,
+        lon: hub.value.longitude,
+        radius: 500
+      },
+      'public',
+      'geo'
+    )
+
+    // Group offers by product
+    const productsMap = new Map<string, { uuid: string; name: string }>()
+    offersData.value?.nearestOffers?.forEach((offer: any) => {
+      if (offer?.productUuid) {
+        if (!productsMap.has(offer.productUuid)) {
+          productsMap.set(offer.productUuid, {
+            uuid: offer.productUuid,
+            name: offer.productName || ''
+          })
+        }
+      }
+    })
+    products.value = Array.from(productsMap.values())
+  }
 } catch (error) {
   console.error('Error loading hub:', error)
 } finally {