Phase 7b: Migrate deprecated RPCs to Customer* RPCs

- Profile/Index: InitiateBasePackagePayment → CustomerPurchasePackage
  - Fetches base package via GetCustomerPackages, passes PackageId + PurchaseMethod
- Profile/PaymentCallback: VerifyBasePackagePayment → CustomerVerifyPackagePurchase
  - Uses Authority/Status (from ZarinPal callback) + orderId (from embedded URL param)
  - TransactionId no longer required (CMS finds it internally)

src/FrontOffice.Main/Pages/Profile/Index.razor.cs

@@ -413,13 +413,24 @@ public partial class Index
         
         try
         {
-            // Create callback URL for payment verification
-            var callbackUrl = $"{Navigation.BaseUri}profile/payment-callback";
-            
-            // Call BFF to initiate payment (UserId is taken from JWT token in BFF)
-            var response = await PackageContract.InitiateBasePackagePaymentAsync(new InitiateBasePackagePaymentRequest
+            // Get available packages and pick the first (base) one
+            var packages = await PackageContract.GetCustomerPackagesAsync(new GetCustomerPackagesRequest());
+            var basePackage = packages?.Models?.FirstOrDefault();
+            if (basePackage == null)
             {
-                CallbackUrl = callbackUrl
+                Snackbar.Add("پکیجی برای خرید یافت نشد", Severity.Error);
+                return;
+            }
+            
+            // Call CMS to initiate purchase (UserId from JWT, PackageId explicit)
+            // First, get orderId — then embed in callback URL
+            var tempCallbackUrl = $"{Navigation.BaseUri}profile/payment-callback";
+            
+            var response = await PackageContract.CustomerPurchasePackageAsync(new CustomerPurchasePackageRequest
+            {
+                PackageId = basePackage.Id,
+                CallbackUrl = tempCallbackUrl,
+                PurchaseMethod = PurchaseMethodEnum.PurchaseMethodGateway
             });
             
             if (!response.Success)
@@ -429,6 +440,8 @@ public partial class Index
             }
             
             // Redirect to payment gateway
+            // ZarinPal appends ?Authority=...&Status=... to callback URL
+            // PaymentCallback uses Authority+Status to verify via CustomerVerifyPackagePurchase
             if (!string.IsNullOrEmpty(response.PaymentGatewayUrl))
             {
                 Navigation.NavigateTo(response.PaymentGatewayUrl, forceLoad: true);