List workspace checkpoints

curl -X GET "https://api.nevia.cloud/v1/checkpoints?workspace=01d4cnjjq40hnnh0nwmkg35nv2h" \
  -H "Authorization: Bearer $TOKEN"

{
  "checkpoints": [
    {
      "id": "01d4cnjkwhftngfp8vkmp723mhv",
      "workspace": "01d4cnjjq40hnnh0nwmkg35nv2h",
      "source_type": "computer",
      "source": "01d4cnjk3xg90y576w8y6t4gdwm",
      "name": "before-migration",
      "consistency": "crash",
      "state": "ready",
      "generation": 1,
      "image_digest": "string",
      "size_bytes": 5368709120,
      "parent": null,
      "error": null,
      "created_at": "2026-09-10T12:34:56Z",
      "deleted_at": null
    }
  ],
  "next_cursor": "string",
  "has_more": true
}