curl -X PATCH "https://api.magpipe.ai/functions/v1/scheduled-actions/123e4567-e89b-12d3-a456-426614174000" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"status": "cancelled"}'

{
  "id": "123e4567-e89b-12d3-a456-426614174000",
  "action_type": "send_sms",
  "scheduled_at": "2026-01-15T18:00:00.000Z",
  "status": "cancelled",
  "parameters": {
    "recipient_phone": "+14155551234",
    "recipient_name": "John Smith",
    "message": "Your appointment is in 1 hour!"
  },
  "created_at": "2026-01-14T12:00:00.000Z"
}

{
  "error": "Cannot cancel action with status: processing"
}

{
  "error": "Scheduled action not found"
}