feat(payments): implement Payments module with VNPay, MoMo, ZaloPay integration
Implement complete payment processing module following DDD + CQRS patterns:
- Domain layer: PaymentEntity aggregate, Money value object, domain events
- Infrastructure: PrismaPaymentRepository, VnpayService, MomoService, ZalopayService
- PaymentGatewayFactory pattern for provider abstraction
- CQRS Commands: CreatePayment, HandleCallback, RefundPayment
- CQRS Queries: GetPaymentStatus, ListTransactions
- Callback/webhook endpoints with signature verification and idempotency
- 23 unit tests covering domain, VNPay service, and gateway factory
Co-Authored-By: Paperclip <noreply@paperclip.ing>
ad7713968a