List pricing plans

Example response

{
  "data": [
    {
      "id": "plan_abc123def456",
      "businessId": "biz_789xyz",
      "name": "API Calls",
      "unitType": "api_call",
      "unitPriceUsd": "0.001000",
      "unitPrice": "0.000920",
      "currency": "USD",
      "pricingModel": "FLAT",
      "tiers": [
        {
          "minQuantity": "0",
          "maxQuantity": "1000",
          "unitPriceUsd": "0.001000",
          "unitPrice": "0.000920",
          "packageSize": 1000
        }
      ],
      "creditsPerUnit": "10",
      "productCategoryId": "cat_core",
      "isActive": true,
      "createdAt": "2024-01-15T10:30:00.000Z",
      "updatedAt": "2024-01-15T10:30:00.000Z"
    }
  ]
}