Retrieves a heartbeat

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

{
  "data": {
    "id": "b1151744-478e-43d9-a54c-26c9f2db5897",
    "type": "heartbeats",
    "attributes": {
      "slug": "excepturi-temporibus-et-quibusdam",
      "name": "Excepturi temporibus et quibusdam.",
      "description": "Et dicta non voluptate.",
      "alert_summary": "API is down",
      "alert_description": null,
      "alert_urgency_id": "123bbc5b-bd87-4e64-8344-9d3fe77cf91a",
      "interval": 7,
      "interval_unit": "hours",
      "notification_target_id": "212",
      "notification_target_type": "User",
      "ping_url": "http://localhost:3001/v1/heartbeats/b1151744-478e-43d9-a54c-26c9f2db5897/ping",
      "secret": "heartbeat_9625197a2ae88e69c418901e6e695ec3f2f41f8a7a35ea87c57e0da81e9f38b4",
      "email_address": "heartbeat-90ec446685ecc72123b9bb8177a28549@test.email.rootly.com",
      "last_pinged_at": null,
      "expires_at": null,
      "enabled": false,
      "status": "waiting",
      "updated_at": "2025-11-19T20:41:03.464-08:00",
      "created_at": "2025-11-19T20:41:03.464-08:00"
    }
  }
}