Retrieves a heartbeat

curl --request GET \
  --url https://api.rootly.com/v1/heartbeats/{id} \
  --header 'Authorization: Bearer <token>'

{
  "data": {
    "id": "45aa5a06-dc60-429f-9512-f3643d76ad7e",
    "type": "heartbeats",
    "attributes": {
      "slug": "velit-sint-dolor-qui",
      "name": "Velit sint dolor qui.",
      "description": "Et veritatis corporis accusantium.",
      "alert_summary": "API is down",
      "alert_description": null,
      "alert_urgency_id": "b0701763-0b44-4160-aaee-027c30b43458",
      "interval": 7,
      "interval_unit": "seconds",
      "notification_target_id": "212",
      "notification_target_type": "User",
      "ping_url": "http://localhost:3001/v1/heartbeats/45aa5a06-dc60-429f-9512-f3643d76ad7e/ping",
      "secret": "heartbeat_787c87625bca8eca79cac9a6f330c76a68d8cc64b0966c160e5decd058c37cb5",
      "email_address": "heartbeat-0363e54ada297d4e943f3f1e430ffdca@test.email.rootly.com",
      "last_pinged_at": null,
      "expires_at": null,
      "enabled": false,
      "status": "waiting",
      "updated_at": "2025-11-21T14:30:37.064-08:00",
      "created_at": "2025-11-21T14:30:37.064-08:00"
    }
  }
}