- Refactor PaymentController to delegate payment processing to PaymentManager.
- Add findByOrderIdForUpdate method in PaymentRepository for pessimistic locking.
- Create PaymentLog entity and repository for auditing payment actions.
- Implement startGatewayHandoff and processCallback methods in PaymentManager.
- Introduce transaction handling and logging for payment verification.
- Update payment flow to ensure idempotency and prevent race conditions.
- Enhance security by logging sensitive actions without exposing credentials.
- Update database schema with migration for payment_logs table.
- Document changes in payment flow architecture.
