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.Infrastructure/Services/Payment/ZarinPalPaymentService.cs

@@ -221,6 +221,9 @@ public class ZarinPalPaymentService : IPaymentGatewayService
                     RefId = refId,
                     TrackingCode = result.Data.RefId?.ToString(),
                     Amount = (result.Data.Amount ?? 0) / 10m, // ریال → تومان
+                    CardPan = result.Data.CardPan,
+                    CardHash = result.Data.CardHash,
+                    VerificationCode = result.Data.Code,
                     Message = result.Data.Code == 101
                         ? "تراکنش قبلاً تأیید شده"
                         : "تراکنش موفق"