Refactor-Global-State-Aggregation

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 refactor, rationale, tests. Refactor transaction aggregation that mutates module-level totals into a pure reducer returning a fresh summary.

{
  "metrics": {
    "visible": {
      "checks": [
        {
          "contains": [
            "pure reducer"
          ]
        },
        {
          "contains": [
            "fresh summary"
          ]
        },
        {
          "contains": [
            "transaction"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "module-level"
          ]
        },
        {
          "contains": [
            "no mutation"
          ]
        },
        {
          "contains": [
            "totals"
          ]
        }
      ]
    },
    "intent": {
      "checks": [
        {
          "contains": [
            "state isolation"
          ]
        },
        {
          "contains": [
            "accumulator"
          ]
        },
        {
          "contains": [
            "aggregation"
          ]
        }
      ]
    }
  }
}