# T2 / NW2 — prose-vs-Workflow bake-off results

**Status (S10):** Build complete + **smoke run (1 run/arm) done**. Full ≥3-runs/arm
measurement is **pending operator go/no-go** (operator posture: "build + smoke, then pause").
**This document records the smoke; it is NOT the full T2 §5 verdict.**

Resolves: the build + de-risk half of `docs/W1-narrow-wins-plan.md §S10`.

---

## Setup

| Item | Value |
|------|-------|
| Fixture | `tests/fixtures/bakeoff/` — real diff of commit `b149538` (NW1) + brief reconstructed from `docs/W1-narrow-wins-plan.md §S9` |
| Delivered diff | 3 files, +438/-3 (`commands/trekreview.md`, `lib/review/findings-schema.mjs`, `tests/lib/findings-schema.test.mjs`) |
| Triage | all 3 files `summary-only` (deterministic Phase-4 classifier) |
| Model | `opus` (reviewer + coordinator agent defaults) |
| Arm A (prose) | reviewers spawned via Agent tool, prose trailing-JSON contract (validated by NW1 `findings-schema`) |
| Arm B (Workflow) | `scripts/trekreview-armB.workflow.mjs` via Workflow tool: `parallel([conformance, correctness])` schema-forced → JS dedup-by-triplet → `agent(review-coordinator)` verdict schema |
| Fidelity metric | `lib/review/fidelity-diff.mjs` `fidelityDiffStructured` (verdict + jaccard over `(file,line,rule_key)`-IDs + severity/rule cross-check) |

## Smoke results (single run per arm)

| | Arm A (prose) | Arm B (Workflow) |
|---|---|---|
| Reviewers run | 2 | 2 |
| Raw findings | 0 | 1 |
| After coordinator | 0 (coordinator moot — 0 findings) | 0 (coordinator dropped the 1 finding) |
| **Verdict** | **ALLOW** | **ALLOW** |
| Agents | 2 | 3 (2 reviewers + coordinator) |
| Subagent tokens | ~72.3k (34.3k + 38.0k; no coordinator) | ~100.9k (incl. coordinator) |
| Wall-time | ~70 s (parallel reviewers) | ~157 s (full pipeline) |

### PRIMARY metric — output fidelity: **EQUIVALENT**

```
fidelityDiffStructured(ArmA, ArmB) =
  { verdictMatch: true, jaccard: 1, countA: 0, countB: 0,
    severityMismatches: [], ruleKeyMismatches: [], equivalent: true }
```

⚠ **Caveat — thin finding surface.** Both arms returned **0 final findings** on
this clean, TDD'd fixture, so fidelity is confirmed only at the **verdict** level
(ALLOW ≡ ALLOW); the finding-*set* fidelity is trivially equal at zero and was
**not stressed**. A reviewer-level divergence *did* appear (Arm B raised 1 raw
finding, its coordinator filtered it; Arm A raised 0) — masked at the verdict
level. Quantifying that divergence is exactly what the full run on a
richer-finding-surface fixture must do.

### Secondary metrics (smoke, single-run — not medians)

- **JSON-robustness (the F2 win):** Arm B's reviewers were **schema-forced**
  (StructuredOutput) — typed findings, zero `JSON.parse`; the 1 raw finding +
  the coordinator verdict both conformed with no re-ask. Arm A's trailing-JSON
  validated clean via NW1 `findings-schema`. Win demonstrated structurally; the
  parse-error/re-ask delta needs a fixture that actually provokes malformed JSON.
- **Classifier interference: 0.** Arm B's 2-agent fan-out + coordinator (3 agents)
  ran with no denied/missing spawns. Confirms S8 F4 for trekreview's small
  fan-out under the default mode. (`auto`/`bypass` still to be checked in the full run.)
- **Token cost:** preliminary and **not yet comparable** — Arm B ran a coordinator
  (on its 1 finding) that Arm A did not. Single run; no medians.
- **Control/visibility:** Arm B runs in the background; intermediate findings are
  visible in the workflow transcript + `/workflows`. Operator-gate (the review.md
  write) is unaffected — both arms return structured `{verdict, findings}` and
  Phase 7 rendering stays shared/prose.

## Smoke verdict

**SMOKE PASS — machinery validated.** Arm B (Workflow substrate) runs the full
Phase 5–6 pipeline end-to-end, fidelity-**equivalent** to Arm A at the verdict
level, with **zero classifier interference**. The build is sound: NW1 schema,
fidelity-diff, fixture, and the Arm B port all work together.

This is **not** the T2 §5 POSITIVE/NEGATIVE verdict — that needs the full
≥3-runs/arm measurement with a finding-rich fixture.

## Go / no-go recommendation (operator decides)

**Recommend: proceed to the full ≥3-runs/arm run (S10 part B)** with two changes:
1. **Use a richer-finding-surface fixture** (a larger real voyage commit, or seed
   the fixture with a few genuine issues) so finding-*set* fidelity is actually
   stressed — the smoke only proved verdict fidelity at 0 findings.
2. **Match the arms' coordinator path** (run Arm A's coordinator too, even at low
   finding counts) so the token/wall-time comparison is apples-to-apples, and
   add the `auto`/`bypass` classifier-interference check (F4).

If the operator prefers, S11 can instead record "port built + smoke-validated;
full measurement deferred" and integrate behind the opt-in `--workflow` flag on
the smoke evidence alone — weaker, but the substrate is demonstrably functional.