Use graph-based offers and remove radius filters

app/composables/useCatalogHubs.ts

@@ -61,15 +61,13 @@ export function useCatalogHubs() {
   const fetchPage = async (offset: number, replace = false) => {
     if (replace) isLoading.value = true
     try {
-      // If filtering by product, use nearestHubs with global search
-      // (center point 0,0 with very large radius to cover entire globe)
+      // If filtering by product, use nearestHubs (graph-based)
       if (filterProductUuid.value) {
         const data = await execute(
           NearestHubsDocument,
           {
             lat: 0,
             lon: 0,
-            radius: 20000, // 20000 km radius covers entire Earth
             productUuid: filterProductUuid.value,
             useGraph: true,
             limit: 500 // Increased limit for global search