curl --request GET \
  --url http://localhost:3000/api/canary/balance \
  --header 'Authorization: Bearer <token>'

{
  "id": "balance_merchant_456",
  "merchantId": "merchant_456",
  "amount": 50000,
  "currency": "ZAR",
  "available": 50000,
  "pending": 0,
  "createdAt": "2025-01-15T10:30:00.000Z",
  "updatedAt": "2025-01-15T10:30:00.000Z"
}