curl --request DELETE \
  --url https://api.coval.dev/v1/scheduled-runs/{scheduled_run_id} \
  --header 'X-API-Key: <api-key>'

{
  "error": {
    "code": "INVALID_ARGUMENT",
    "message": "Invalid request parameter",
    "details": [
      {
        "field": "schedule_expression",
        "description": "Must be 'rate(...)' or 'cron(...)' format"
      }
    ]
  }
}