Refactor-String-Concat-Template

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 a function that builds a URL and a greeting message using string concatenation (+ operator) into equivalent template literals. The output strings must be byte-for-byte identical for all inputs.

{
  "metrics": {
    "visible": {
      "checks": [
        {
          "contains": [
            "template literal"
          ]
        },
        {
          "contains": [
            "backtick"
          ]
        },
        {
          "contains": [
            "interpolation"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "identical output"
          ]
        },
        {
          "contains": [
            "no concatenation operator"
          ]
        },
        {
          "contains": [
            "special characters"
          ]
        }
      ]
    },
    "intent": {
      "checks": [
        {
          "contains": [
            "readability"
          ]
        },
        {
          "contains": [
            "modernization"
          ]
        },
        {
          "contains": [
            "reduce error-prone concatenation"
          ]
        }
      ]
    }
  }
}