List board item filesystem

curl --request GET \
  --url https://api.wacht.dev/ai/actor-projects/{project_id}/board/items/{item_id}/filesystem \
  --header 'Authorization: <api-key>'

{
  "exists": true,
  "files": [
    {
      "path": "<string>",
      "name": "<string>",
      "is_dir": true,
      "size_bytes": 123,
      "modified_at": "2023-11-07T05:31:56Z"
    }
  ]
}