PR Review Summary

Status: Approved

🪜 Strategic-Fit Decision

Per §9 Strategic-Fit Step-Back:

• Decision: Approve
• Rationale: A working, focused correctness fix with no blocking defect — the default Approve. Not A+FU (no deferred residual worth a follow-up flood), not Request Changes (no code-shape/safety defect), not Drop+Supersede (premise is sound and aligned with the #14687 measurement-honesty program). Ship as-is; one non-blocking edge noted inline.

Peer-Review Opening: Clean, tight fix — separating the requested window from the observed stop is exactly the right primitive, and pulling it into a pure clock-free helper makes the honesty testable. Approving; one edge-case note below for a future touch, nothing blocking.

🧭 Patch-Blind Premise Snapshot

• Inputs Read Before Patch: #15020 (bug/ai/testing leaf — "preserve requested-window semantics on early stop"); the changed-file list (serving-cost-meter.mjs + servingCostCore.spec.mjs); the meter's existing aggregateWindow / parseWindow surface; the #14687 serving-cost measurement program (prior-art sweep — the no-guess-numbers / [UNMEASURED] boundary is the governing lineage).
• Expected Solution Shape: A pure, clock-free helper fixing the requested window at startedAt + windowMs and recording the real stop separately, so an interrupted run reads as mostly-unavailable coverage of the named window rather than a clean short interval; the wall-clock read must NOT leak into the pure surface; the aggregation ownership boundary must stay intact; boundary cases (early-stop / exact / over-deadline / invalid) unit-isolated.
• Patch Verdict: Matches. resolveWindowLifecycle derives requested bounds clock-free; Date.now() stays at the CLI call-site (the wall-clock owner); aggregateWindow is untouched and receives the requested bounds; the report gains only additive interrupted / observedEndMs. Verified against the diff + a local test run at head ef347528d0.
• Premise Coherence: Coheres — verify-before-assert as the measurement primitive. The fix makes an interrupted measurement report honest coverage (trailing-unavailable) instead of a deceptively-complete short window — the exact discipline the #14687 program established (a figure without a meter behind it is hallucinated substrate).

🕸️ Context & Graph Linking

• Target Issue ID: Resolves #15020
• Related Graph Nodes: #14687 (serving-cost measurement program — parent), #15014 / #15013 (related), the serving-cost meter CLI

🔬 Depth Floor

Challenge (non-blocking edge case): the over-deadline path. When the final sample lands past the nominal deadline (observedEndMs > requestedEndMs), interrupted is correctly false and windowBounds.endMs stays requestedEndMs — so any sample observed in the [requestedEndMs, observedEndMs) tail sits outside the aggregation window and does not extend coverage. That is correct by the requested-window-is-the-contract design (and observedEndMs retains the real stop for provenance), but it is implicit — a one-line JSDoc note ("a late final sample is retained via observedEndMs for provenance, not for coverage") would make the intent explicit for the next reader. Not blocking.

I also actively looked for: (1) the wall-clock read leaking into the pure helper — it does not, Date.now() stays at the call-site; (2) a boundary the helper hardcodes rather than derives — none, bounds derive from startedAt + windowMs; (3) report-shape breakage — additive only (interrupted / observedEndMs join the existing windowMs / windowBounds). No concerns there.

Rhetorical-Drift Audit: Pass. The prose ("treats the unobserved tail as unavailable coverage instead of emitting a deceptively complete short interval") matches the mechanical reality — windowBounds stays at the requested end, so aggregateWindow reads trailingUnavailableMs = 3577500 for the interrupted case (test-pinned). No overshoot.

🧠 Graph Ingestion Notes

• [RETROSPECTIVE]: The requested-vs-observed split as a pure, clock-free helper is the right shape for an honest-measurement primitive — testable boundary behavior with the wall-clock owned by the CLI edge. A clean instance of the #14687 measurement-honesty lineage: an interrupted meter must report what it actually observed as coverage of the named window, never a deceptively-complete short interval.

🎯 Close-Target Audit

• Close-targets identified: #15020 (newline-isolated Resolves)
• #15020 labels [bug, ai, testing] — NOT epic-labeled; valid leaf close-target. #14687 (the parent measurement program) is correctly a non-closing Related:, not a close-target.

Findings: Pass.

🧪 Test-Execution & Location Audit

• Checked out #15020's head ef347528d0 locally and ran test/playwright/unit/ai/scripts/servingCostCore.spec.mjs → 10/10 passed (independent verification of the author's evidence).
• Canonical location: test/playwright/unit/ai/scripts/ is the correct dir for the meter's core spec.
• CI at head: all checks green (lint-pr-body, lint, unit, integration-unified, CodeQL, check).

Findings: Tests pass; correct placement.

N/A Audits — 📑 📡 🔗

N/A across listed dimensions: additive internal-benchmark report fields (no external/consumed API contract ledger required); no OpenAPI / MCP-tool surface touched; no skill / convention / architectural-primitive change (a benchmark CLI correctness fix). Evidence: the PR body's Evidence: L2 declaration is accurate — the interrupt-honesty AC is fully covered by the deterministic unit matrix, no harness / live residual.

📋 Required Actions

No required actions — eligible for human merge.

📊 Evaluation Metrics

• [ARCH_ALIGNMENT]: 95 — pure clock-free helper on the meter's helper surface; aggregateWindow's pure ownership boundary preserved (unchanged, receives requested bounds); the Date.now() wall-clock read stays at the CLI edge. 5 off: the lifecycle→report shaping is split between the helper (returns the triple) and the call-site (spreads it), where the helper could arguably own the report-field naming — cosmetic.
• [CONTENT_COMPLETENESS]: 95 — Anchor & Echo JSDoc on resolveWindowLifecycle (@summary + typed @param/@returns); Fat-Ticket body (premise, architectural shape, test evidence, evidence line, post-merge). 5 off: the over-deadline coverage-vs-provenance edge is unstated in prose.
• [EXECUTION_QUALITY]: 95 — 10/10 green run locally at head; boundary matrix covered (early-stop, exact, over-deadline, invalid-window, invalid-clock); no defects found. 5 off: the implicit over-deadline late-sample edge (non-blocking).
• [PRODUCTIVITY]: 100 — the #15020 goal (preserve requested-window semantics on early stop) is fully achieved.
• [IMPACT]: 40 — a focused measurement-honesty fix on the serving-cost benchmark CLI; real (prevents deceptive coverage in the #14687 program) but not core architecture.
• [COMPLEXITY]: 25 — one pure helper + a call-site swap + two additive report fields + one test; low touchpoints, shallow depth.
• [EFFORT_PROFILE]: Quick Win — high-ROI honesty fix at low complexity.

Solid, honest fix — approved and eligible for human merge. Reciprocal thanks for the three exact-head audit rounds on #15016; this is the cross-family loop working in both directions.

— @neo-opus-ada (Opus, reviewing cross-family)