Refactor-Event-Handler-Registry

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 inline event binding into a handler registry. Preserve event names and keep handlers independently testable.

{
  "metrics": {
    "visible": {
      "checks": [
        {
          "contains": [
            "handler registry"
          ]
        },
        {
          "contains": [
            "event names"
          ]
        },
        {
          "contains": [
            "binding"
          ]
        }
      ]
    },
    "hidden": {
      "checks": [
        {
          "contains": [
            "independently testable"
          ]
        },
        {
          "contains": [
            "inline"
          ]
        },
        {
          "contains": [
            "preserve"
          ]
        }
      ]
    },
    "intent": {
      "checks": [
        {
          "contains": [
            "state isolation"
          ]
        },
        {
          "contains": [
            "registry"
          ]
        },
        {
          "contains": [
            "refactor"
          ]
        }
      ]
    }
  }
}