[cart-guest-delivery-fee] Show login prompt instead of unavailable for guest cart delivery fee

PediFoods/Views/Main/CartView.swift

@@ -180,6 +180,9 @@ struct CartView: View {
     }
 
     private var deliveryFeeLabel: String {
+        guard appState.session.isAuthenticated else {
+            return "Login para calcular"
+        }
         if isLoadingDeliveryFee {
             return "Calculando..."
         }
@@ -293,6 +296,11 @@ struct CartView: View {
             selectedCustomerAddress = nil
             return
         }
+        guard appState.session.isAuthenticated else {
+            deliveryFee = nil
+            selectedCustomerAddress = nil
+            return
+        }
 
         isLoadingDeliveryFee = true
         defer { isLoadingDeliveryFee = false }