Optimize catalog loading: backend bounds filtering + early returns

- Add bounds (west/south/east/north) parameters to GetNodes query
- Add setBoundsFilter to useCatalogHubs, useCatalogSuppliers, useCatalogProducts
- Replace client-side bounds filtering with backend query
- Add early return to setProductFilter to avoid redundant fetches
- Watch filterByBounds to trigger backend refetch when checkbox changes

app/composables/useCatalogHubs.ts

@@ -12,6 +12,7 @@ const isLoading = ref(false)
 const isLoadingMore = ref(false)
 const isInitialized = ref(false)
 const filterProductUuid = ref<string | null>(null)
+const filterBounds = ref<{ west: number; south: number; east: number; north: number } | null>(null)
 
 export function useCatalogHubs() {
   const { t } = useI18n()
@@ -69,9 +70,21 @@ export function useCatalogHubs() {
       // Default: fetch all hubs with filters
       const transportType = selectedFilter.value === 'all' ? null : selectedFilter.value
       const country = selectedCountry.value === 'all' ? null : selectedCountry.value
+      const bounds = filterBounds.value
       const data = await execute(
         GetNodesDocument,
-        { limit: PAGE_SIZE, offset, transportType, country },
+        {
+          limit: PAGE_SIZE,
+          offset,
+          transportType,
+          country,
+          ...(bounds && {
+            west: bounds.west,
+            south: bounds.south,
+            east: bounds.east,
+            north: bounds.north
+          })
+        },
         'public',
         'geo'
       )
@@ -111,12 +124,20 @@ export function useCatalogHubs() {
   })
 
   const setProductFilter = (uuid: string | null) => {
+    if (filterProductUuid.value === uuid) return // Early return if unchanged
     filterProductUuid.value = uuid
     if (isInitialized.value) {
       fetchPage(0, true)
     }
   }
 
+  const setBoundsFilter = (bounds: { west: number; south: number; east: number; north: number } | null) => {
+    filterBounds.value = bounds
+    if (isInitialized.value) {
+      fetchPage(0, true)
+    }
+  }
+
   // Initialize data if not already loaded
   const init = async () => {
     if (!isInitialized.value && items.value.length === 0) {
@@ -142,6 +163,7 @@ export function useCatalogHubs() {
     fetchPage,
     loadMore,
     init,
-    setProductFilter
+    setProductFilter,
+    setBoundsFilter
   }
 }