# Experiment 60B.45 — Closure metadata capture in canonical live harness

**Date:** 2026-08-14
**Branch:** `feature/closure-metadata-capture-v0.39`

## Purpose

Expose `activeUnknownNodeId` and `selectedQuestion` explicitly in the canonical live harness output/capture layer so the exact 60B.44 live closure case can be rerun and classified from direct evidence rather than inference.

## Why this was needed

60B.44 already confirmed live graph-level closure:

- customer factor resolved in place
- decision resolved in place
- both options preserved
- zero new unknowns

But the canonical harness did not explicitly emit/store:

- final `activeUnknownNodeId`
- final `selectedQuestion`

That meant null closure had to be inferred from omission instead of being evidenced directly.

## Exact harness change

Modified only the canonical harness layer:

- `scripts/reproduce-multi-turn-investigation.mjs`
- `tests/reproduce-multi-turn-investigation.harness.test.js`

For accepted updates, the harness now explicitly exposes:

- `finalActiveUnknownNodeId`
- `finalSelectedQuestion`

### Raw source of each field

- `finalActiveUnknownNodeId` ← `updatedSituationGraph.activeUnknownNodeId`
- `finalSelectedQuestion` ← `updateResult.json.selectedQuestion`

If either value is actually null, the harness now prints/stores `null` explicitly rather than omitting the field.

## Explicit null distinction

This was the critical apparatus gap:

- `null` means the production result explicitly cleared the field
- omitted/unavailable means the harness never captured it

The updated harness now preserves that distinction.

## Focused deterministic tests

Added focused coverage in `tests/reproduce-multi-turn-investigation.harness.test.js` for:

1. explicit null `finalActiveUnknownNodeId`
2. explicit null `finalSelectedQuestion`
3. populated values surviving unchanged
4. all existing harness capture/regression behaviour remaining green

## Validation

Command run:

```bash
npx vitest run tests/reproduce-multi-turn-investigation.harness.test.js
```

Result:

- PASS — `67/67`

## What is now possible

The exact 60B.44 live closure case can now be rerun once and classified from direct harness evidence for:

- `finalActiveUnknownNodeId: null`
- `finalSelectedQuestion: null`

without changing any production reasoning logic or production API shape.