Feature Request: Expose build error details via /api/v2/builds endpoint

We're using the /api/v2/builds endpoint to track ElastiCube build outcomes (successes, failures, retries). The endpoint works well for tracking basic build task status, but we are running into severe limitations regarding failure visibility.

Currently, when the build fails, the API response only returns a status of [Failed] with no accompanying error message or failure reason. The actual error detail is visible in the Sisense UI under the cube's build history, but there is no way to retrieve it through the REST API.

Request: Expose the build error message or error category as fields in the GET /api/v2/builds and GET /api/v2/builds{buildId} response objects. Even a brief top-level error summary would be sufficient to make monitoring and alerting useful. This would benefit any team building operational dashboards and alerting scripts around Sisense build reliability, making automated monitoring truly actionable.