Add refusals tab to the order dashboard

Orders whose Nova Poshta status is a refusal (102/103/105/108) now show
only under «Отказы», whether or not they have a receipt. GET /orders takes
tab=no_receipt|has_receipt|refused instead of has_receipt. NP statuses are
also polled for orders that already have a receipt, until NP reports a
final status.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/api/orders.ts

@@ -1,8 +1,8 @@
 import { apiFetch } from '@/api/client'
-import type { Order, OrderUpdate } from '@/features/orders/types'
+import type { Order, OrderTab, OrderUpdate } from '@/features/orders/types'
 
-export function getOrders(hasReceipt: boolean): Promise<Order[]> {
-  return apiFetch<Order[]>(`/orders?has_receipt=${hasReceipt}`)
+export function getOrders(tab: OrderTab): Promise<Order[]> {
+  return apiFetch<Order[]>(`/orders?tab=${tab}`)
 }
 
 export function deleteOrder(orderId: string): Promise<void> {