add WebSocket support for real-time delivery updates with JWT authentication and automatic reconnection

frontend/src/api/deliveries.ts

@@ -3,7 +3,7 @@ import { backendDateToFrontend } from '../utils/date';
 import type { Delivery, DeliveryRequestSource, PickupLocation, DeliveryStatus } from '../types';
 
 // Types matching backend responses
-interface BackendDelivery {
+export interface BackendDelivery {
   id: string;
   date: string; // YYYY-MM-DD from pgtype.Date
   pickup_location: PickupLocation;
@@ -57,7 +57,7 @@ interface UpdateDeliveryResponse {
 }
 
 // Map backend delivery to frontend delivery
-function mapBackendToFrontend(backend: BackendDelivery): Delivery {
+export function mapBackendToFrontend(backend: BackendDelivery): Delivery {
   return {
     id: backend.id,
     date: backendDateToFrontend(backend.date),