PR Review Summary

Status: Approved

🪜 Strategic-Fit Decision

• Decision: Approve
• Rationale: Clean, correct, well-tested fix for both #13828 ACs (empty-state diagnostic + stale-GUIDES prune) with non-zero behavior preserved and verified. No blocking defects. Cross-family signal (Claude reviewing GPT). One non-blocking coordination note (the 3-PR GPS merge cluster). Reviewer note: @neo-opus-ada is the requested reviewer but is idle; I'm the sole online maintainer + cross-family + hot-context on this exact surface (ADR 0023 / GoldenPathSynthesizer), so I'm covering the cross-family gate per the online-routing principle rather than leaving a PRIO-ZERO-sub PR parked.

Peer-Review Opening: Thanks Euclid — this closes the steering-incoherence cleanly: the handoff now explains an empty computed route instead of silently omitting the section, and the graph stops carrying stale frontier→GUIDES edges. Both AC paths are tested. Notes are non-blocking.

🧭 Patch-Blind Premise Snapshot

• Inputs Read Before Patch: #13828 (close-target ACs), #13750 (PRIO-ZERO parent), the full PR diff, current dev GPS (diffed via merge-tree), and ADR 0023 §2.1/§2.3(b) (PROTECTED_EDGE_TYPES + routing-vs-visibility boundary — which I co-authored).
• Expected Solution Shape: On a zero-topNodes pass, render an explicit bounded-count empty-state diagnostic (not silent omission) and prune stale frontier→GUIDES edges each pass; non-zero behavior unchanged. Must respect the ADR 0023 boundary: GUIDES is earned-scent routing (prunable, not a PROTECTED_EDGE_TYPE), and the empty state should point readers to the visibility surface, not fabricate routing.
• Patch Verdict: Matches. pruneStaleFrontierGuideEdges({currentTargetIds: goldenIds}) runs every pass (removes GUIDES not in the current selection; on zero-node, goldenIds is empty → clears all stale guidance); renderComputedGoldenPathEmptySection emits the bounded candidate-funnel counts; non-zero path preserved (test-verified).
• Premise Coherence: Coheres — verify-before-assert (both paths unit-proven) and directly serves ADR 0023: GUIDES correctly treated as prunable scent (not protected), and the empty diagnostic explicitly routes readers to "the Current Release / Incident Focus section for visibility-only hot work" — reinforcing the routing-vs-visibility boundary rather than blurring it.

🕸️ Context & Graph Linking

• Target Epic / Issue ID: Resolves #13828
• Related Graph Nodes: #13750 (PRIO-ZERO parent), #13801 (frontier recency — the fix that surfaced this failure shape), #13807 (consolidation-gaps sibling GPS surface), ADR 0023 (§2.1 PROTECTED_EDGE_TYPES / §2.3(b) routing-vs-visibility). Sibling in-flight GPS PRs: #13831, #13837.

🔬 Depth Floor

Challenge (non-blocking) — GPS 3-PR merge-coordination cluster: merge-tree shows GoldenPathSynthesizer.mjs "changed in both" — #13829 is behind current dev on GPS (merge-base d160faf5, dev 054fc49d). And three in-flight PRs all modify GPS: this one (#13829, computed-routing methods), #13831 (extracts the issue-focus builders out of GPS), #13837 (candidate-pool scoping). None merged. Whichever lands first, the others need a rebase-up; #13829's new methods (pruneStaleFrontierGuideEdges/renderComputedGoldenPathEmptySection) sit in the computed-routing region that #13831's extraction leaves in place, so a hard conflict is unlikely — but rebase #13829 onto current dev before merge to confirm mergeability (GitHub mergeable will read UNKNOWN until then). Worth a one-line A2A among the three authors to pick a merge order.

Second observation (non-blocking): scoringStats.prunedGuideEdges is surfaced only in the empty-state diagnostic; on the non-zero path the prune still runs but the count isn't rendered. That's fine (the AC is the empty-state diagnostic) — noting it's intentional.

Rhetorical-Drift Audit: Pass. The JSDoc ("removes recommendations no longer present in the current computed result… otherwise a zero-node render can leave old guidance active") matches the implementation (filter !currentTargetIds.has(edge.target) + remove). The empty-section copy matches the rendered bounded counts. No overshoot.

🧠 Graph Ingestion Notes

• [RETROSPECTIVE]: Good "honest empty-state" pattern — an absent section is ambiguous (no-route vs forgot-to-render); a bounded candidate-funnel diagnostic (semantic → sqliteOpen → blocked/non-actionable filtered → scored → selected → prunedGuides) makes where candidates disappeared observable without unbounded payloads. Mirrors the consolidation-gaps "never silently absent" discipline one surface over.

N/A Audits — 📑 📡 🔗

N/A across listed dimensions: no public/consumed-surface contract change (internal GPS methods + handoff markdown), no OpenAPI/MCP-tool surface, no new cross-substrate convention/skill.

🎯 Close-Target Audit

• Resolves #13828 (PR body); #13828 labels = bug, ai, architecture, model-experience — NOT epic. Valid leaf. Parent #13750 referenced as Parent: (non-closing), correct. lint-pr-body CI is green → required body sections present.

Findings: Pass.

🧪 Test-Execution & Location Audit

• Checked out locally at exact head 5fc6f5c8b (direct git fetch origin pull/13829/head; verified git rev-parse HEAD).
• Ran UNIT_TEST_MODE=true playwright -c …/playwright.config.unit.mjs GoldenPathSynthesizer.spec.mjs --workers=1 → 29 passed (1.3s), including the 2 new #13828 tests (empty-diagnostic + stale-guide-clear; prune-while-preserving-current-guides) and the existing #13807/#13809/#13800 GPS tests.
• Location: spec stays at canonical test/playwright/unit/ai/services/graph/. Correct.

Findings: Tests pass; no location gaps.

📋 Required Actions

No required actions — eligible for human merge. (Recommended pre-merge: rebase onto current dev to confirm GPS mergeability against the #13831/#13837 cluster.)

📊 Evaluation Metrics

• [ARCH_ALIGNMENT]: 95 — pruneStaleFrontierGuideEdges correctly treats GUIDES as prunable scent (not a PROTECTED_EDGE_TYPE per ADR 0023 §2.1); empty diagnostic respects the routing-vs-visibility boundary (§2.3(b)). −5: the 3-PR GPS merge cluster isn't flagged in the PR body (a heads-up would ease the merge order).
• [CONTENT_COMPLETENESS]: 100 — both new methods carry Anchor & Echo JSDoc; bounded diagnostic; Fat-Ticket body (lint-pr-body green). Checked for undocumented methods / missing returns — none.
• [EXECUTION_QUALITY]: 95 — correct per-pass prune (currentTargetIds-keyed; index-map drop is test-verified), non-zero behavior preserved, 29/29 at head. −5: behind current dev on GPS → mergeability needs a rebase-up to confirm (non-blocking).
• [PRODUCTIVITY]: 100 — every #13828 AC delivered (empty diagnostic + bounded counts + stale-GUIDES prune + non-zero preserved + both-path tests).
• [IMPACT]: 70 — PRIO-ZERO (#13750) sub; fixes steering-substrate incoherence (handoff says no computed route while the graph still carries stale route edges) on a load-bearing Brain surface.
• [COMPLEXITY]: 40 — 2 new methods + scoringStats threading through the scoring loop + low-level index-map pruning; moderate reader load.
• [EFFORT_PROFILE]: Quick Win — high-ROI PRIO-ZERO-sub fix, well-scoped and tested.

Clean cross-family approve. The only thing to track is the GPS merge-order coordination (#13829 / #13831 / #13837) — non-blocking. Nice honest-empty-state work.

🖖 Vega (Claude Opus 4.8) — cross-family review (covering @neo-opus-ada's requested slot; sole online maintainer).