feat: add PaymentTransaction table for gateway-level tracking

- New PaymentTransaction entity (Domain/Entities/Payment/) with all gateway fields:
  GatewayProvider, MerchantId, Authority, CardPan, CardHash, RefId, VerificationStatusCode, etc.
- New PaymentTransactionConfiguration with indexes on Authority, GatewayProvider, UserId, TransactionId, RefId
- Added DbSet<PaymentTransaction> to IApplicationDbContext and ApplicationDbContext
- Extended PaymentVerificationResult DTO with CardPan, CardHash, VerificationCode
- Updated ZarinPalPaymentService.VerifyPayment to return CardPan/CardHash/VerificationCode
- Updated all 5 payment consumers to create/update PaymentTransaction:
  * PlaceOrderCommandHandler — creates PaymentTransaction after InitiatePayment
  * PaymentCallbackController — updates PaymentTransaction after VerifyPayment
  * ChargeDiscountWalletCommandHandler — creates PaymentTransaction + fixed callback URL
  * VerifyDiscountWalletChargeCommandHandler — updates PaymentTransaction after verify
  * TransactionsService.CustomerPaymentRequest/Verification — create/update PaymentTransaction
  * PackageService.CustomerPurchasePackage/Verify — create/update PaymentTransaction
- Transaction table untouched — PaymentTransaction is a separate table
- Pattern inspired by PYMS: create row before gateway → update after verify
- EF migration: AddPaymentTransactionTable

src/CMSMicroservice.Application/Common/Interfaces/IPaymentGatewayService.cs

@@ -142,6 +142,21 @@ public class PaymentVerificationResult
     /// پیام
     /// </summary>
     public string? Message { get; set; }
+    
+    /// <summary>
+    /// شماره کارت ماسک‌شده (مثلاً 6037-****-****-1234)
+    /// </summary>
+    public string? CardPan { get; set; }
+    
+    /// <summary>
+    /// هش کارت بانکی
+    /// </summary>
+    public string? CardHash { get; set; }
+    
+    /// <summary>
+    /// کد وضعیت verify از درگاه (100=موفق، 101=تکراری)
+    /// </summary>
+    public int? VerificationCode { get; set; }
 }
 
 /// <summary>