Get processing documents

Example response

{
  "documents": [
    {
      "id": "doc_123",
      "title": "My Document",
      "type": "text",
      "status": "extracting",
      "createdAt": "2024-12-27T12:00:00Z",
      "updatedAt": "2024-12-27T12:01:00Z"
    }
  ],
  "totalCount": 5
}