Refactor-Metrics-Aggregation-Pipeline

The model receives the prompt (and optional system message). The run uses scorer rubric_json_metrics with the JSON configuration below. Pass/fail and partial credit are determined entirely by that scorer against the model output; no human grading.

Return JSON only with keys plan, refactor, tests. A metrics job parses events, groups them, calculates percentiles, and formats output in one loop. Refactor into pipeline stages with stable output.

{
  "metrics": {
    "intent": {
      "checks": [
        {
          "contains": [
            "pipeline stages"
          ]
        },
        {
          "contains": [
            "metrics job"
          ]
        },
        {
          "contains": [
            "stable output"
          ]
        }
      ]
    },
    "visible": {
      "checks": [
        {
          "contains": [
            "parses events"
          ]
        },
        {
          "contains": [
            "groups"
          ]
        },
        {
          "contains": [
            "percentiles"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "same aggregation"
          ]
        },
        {
          "contains": [
            "fixtures"
          ]
        },
        {
          "contains": [
            "boundary cases"
          ]
        }
      ]
    }
  }
}