PR Review Summary

Status: Approve+Follow-Up

🪜 Strategic-Fit Decision

Per §9 Strategic-Fit Step-Back:

• Decision: Approve+Follow-Up
• Rationale: The #13721 delta correctly applies the already-approved #13718 stagedDiff helper to the sibling block-alignment hook. The follow-up is lifecycle/merge-order, not code rework: this is stacked on #13718, so final merge eligibility requires #13718 to land, #13721 to retarget to dev, and full dev-target CI to stay green.

Peer-Review Opening: Reviewed as a first-cycle cross-family review of the #13720 child delta. The code shape matches the ticket and the sibling precedent; the stack/CI boundary is the only caveat.

🧭 Patch-Blind Premise Snapshot

• Inputs Read Before Patch: Issue #13720 body and labels; changed-file list (check-block-alignment.mjs, package.json, check-block-alignment.spec.mjs); #13718 base PR state and CI; base stagedDiff.mjs helper; current PR body/commit close-targets; exact-head PR checks. Memory prior-art sweep was attempted but degraded by the Memory Core embedding write-canary timeout.
• Expected Solution Shape: A correct sibling to #13717/#13718 should add an internal staged-check mode that filters block-alignment violations to staged-added lines only in lint-staged/pre-commit check mode, must NOT weaken whole-file manual checks or --fix, and must fail closed if staged diff detection is unavailable. Test isolation should use a real git repo to prove grandfathered untouched drift is ignored while newly staged drift still fails.
• Patch Verdict: Matches. The diff adds --staged, resolves the git root once, filters allViolations through getStagedAddedLines() only when staged check mode is active, leaves --fix whole-file, wires lint-staged to pass --staged, and adds real-git tests for both the ignored-grandfathered and staged-added-fails cases.

🕸️ Context & Graph Linking

• Target Epic / Issue ID: Resolves #13720
• Related Graph Nodes: #13717, #13718, stagedDiff, block-alignment pre-commit hygiene, model-experience friction→gold

🔬 Depth Floor

Challenge OR documented search (per guide §7.1):

• Challenge: The PR is stacked on claude/13717-hook-diff-scope, so GitHub only ran the stacked PR-body check on #13721. The delta is code-approved, but merge-ready wording must remain conditional until #13718 lands, #13721 retargets to dev, and the retargeted full CI surface is green.

Rhetorical-Drift Audit (per guide §7.4):

• PR description: framing matches the diff. It explicitly says this is stacked on #13718 and retargets after #13718 merges.
• Anchor & Echo summaries: no new public JSDoc/API framing that overshoots durable intent.
• [RETROSPECTIVE] tag: N/A.
• Linked anchors: #13718 actually provides the stagedDiff helper this PR reuses.

Findings: Pass. No rhetorical drift found.

🧠 Graph Ingestion Notes

• [KB_GAP]: N/A — the implementation follows the existing #13718 stagedDiff helper contract.
• [TOOLING_GAP]: Memory Core semantic prior-art sweep was unavailable during review: query_summaries / query_raw_memories returned embedding write-canary timeouts. Review proceeded with GitHub issue/PR state, base-source reads, and exact-head local tests.
• [RETROSPECTIVE]: Good sibling reuse pattern: pre-commit hygiene hooks should diff-scope only the lint-staged path while preserving whole-file manual checks and fail-closed behavior.

🎯 Close-Target Audit

For every issue named as close-target, verify it does NOT carry the epic label:

• Close-targets identified: #13720 in PR body and commit subject.
• #13720 labels checked: ai, architecture, model-experience; no epic label.

Findings: Pass.

🪜 Evidence Audit

• PR body contains an Evidence: declaration line.
• Achieved evidence matches this close-target: the behavior is covered by focused unit tests plus real-git staged-mode integration.
• Residuals are lifecycle-gate only: retarget/full-CI after #13718 merges, not untested product behavior in the delta.
• Evidence-class collapse check: this review treats child-green/local exact-head tests as delta evidence, not as full dev-target CI.

Findings: Pass with stacked-PR caveat.

N/A Audits — 📑 📡 🔗

N/A across listed dimensions: #13721 changes an internal build-script flag wired only into lint-staged; it does not add a public contract ledger surface, MCP OpenAPI description, or cross-skill workflow convention.

🧪 Test-Execution & Location Audit

• Branch checked out locally at exact head 1b8ef36a994cb696678b84d763e813c09f05e063.
• Canonical Location: new coverage stays in existing test/playwright/unit/ai/buildScripts/util/check-block-alignment.spec.mjs beside the script coverage.
• Related verification run: npm run test-unit -- test/playwright/unit/ai/buildScripts/util/stagedDiff.spec.mjs test/playwright/unit/ai/buildScripts/util/check-block-alignment.spec.mjs.
• Result: 24 passed on exact head.
• git diff --check origin/claude/13717-hook-diff-scope...HEAD passed.

Findings: Tests pass.

📋 Required Actions

No required actions for the current #13721 delta — eligible for human merge only after #13718 merges, #13721 is retargeted to dev, and the retargeted full CI remains green.

📊 Evaluation Metrics

• [ARCH_ALIGNMENT]: 94 - The staged-only filter matches #13718 precedent and keeps whole-file checks/fixes intact; 6 deducted only for the unavoidable stacked-retarget lifecycle caveat.
• [CONTENT_COMPLETENESS]: 92 - PR body includes deltas, evidence, stack caveat, and post-merge validation; 8 deducted because the evidence is necessarily child-delta scoped until retarget.
• [EXECUTION_QUALITY]: 95 - Exact-head focused tests passed 24/24, whitespace diff check passed, and fail-closed behavior is preserved; 5 deducted because full dev-target CI has not run on this child PR yet.
• [PRODUCTIVITY]: 96 - All #13720 acceptance criteria are satisfied in the child delta: grandfathered untouched drift no longer blocks, staged-added drift still fails, and focused real-git coverage exists.
• [IMPACT]: 72 - Meaningful MX friction reduction for pre-commit hygiene with narrow blast radius.
• [COMPLEXITY]: 42 - Small three-file delta, but real-git staged semantics and fail-open/fail-closed behavior require careful review.
• [EFFORT_PROFILE]: Quick Win - Low implementation surface with direct reduction in repeated pre-commit friction.

Approved as a stacked delta. Do not treat this as final dev-target merge-ready until the stated retarget/full-CI gate is cleared.