List Payments

NOTE: This method serves two different routes:

• GET /organization/{organizationId}/payments
• GET /merchant/{merchantId}/payments

We don't add #[UrlParam] attributes here because:

1. Each route has a different path parameter (organizationId vs merchantId)
2. Adding both would cause OpenAPI validation errors ("parameter not in path")
3. Scribe auto-detects path parameters from the route URI, so they're documented correctly

The custom OpenAPISpecWriter::operationId() method handles generating unique operation IDs for these routes (listPaymentsByOrganization vs listPaymentsByMerchant).