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>

backend/app/api/v1/orders.py

@@ -10,18 +10,19 @@ from app.schemas.orders import OrderRowOut, OrderUpdateIn
 from app.services import audit
 from app.services import orders as orders_service
 from app.services import receipts as receipts_service
+from app.services.orders import OrderTab
 
 router = APIRouter(prefix="/orders", tags=["orders"], dependencies=[Depends(require_any)])
 
 
 @router.get("", response_model=list[OrderRowOut], response_model_by_alias=False)
 async def list_orders(
-    session: SessionDep, crm: CrmClientDep, has_receipt: bool = False
+    session: SessionDep, crm: CrmClientDep, tab: OrderTab = OrderTab.NO_RECEIPT
 ) -> list[OrderRowOut]:
     # by_alias=False: без этого FastAPI сериализует вложенные OrderGoodOut через
     # CRM-алиасы (SKU/Name/...) вместо snake_case полей, которые ждёт фронтенд.
     await orders_service.sync_orders_from_crm(session, crm)
-    orders = await orders_service.list_orders(session, has_receipt=has_receipt)
+    orders = await orders_service.list_orders(session, tab=tab)
     receipts = await receipts_service.latest_receipts_by_order(
         session, [order.id for order in orders]
     )