feat(payment): implement change payment method (PATCH /payment-method)

- ChangePaymentMethodPayload + ChangePaymentMethodResult models
- ApiService.changePaymentMethod()
- PixPaymentContext gains storeId + order data for payment switch
- PaymentPixView: Trocar button opens ChangePaymentSheet with 3 options
- ChangePaymentSheet: Novo PIX (new QR), Cartão (saved or new), Pagar na Entrega
- ChangePaymentCardSheet + ChangePaymentNewCardView with same card masks/validation
- OrdersView/OrderEntryDestinationView: threaded appState binding

pedi-foods/Sources/PediFoods/Views/Main/ProfileView.swift

@@ -28,7 +28,7 @@ struct ProfileView: View {
 
                 VStack(spacing: 14) {
                     NavigationLink {
-                        OrdersView()
+                        OrdersView(appState: $appState)
                     } label: {
                         ProfileMenuRow(icon: "list.bullet.clipboard.fill", title: "Meus Pedidos")
                     }