feat(enrichment): add revert-recurrence detector for review brief

[jeffrey701]

Summary

Adds a REES analyzer that detects when a PR is reverting or re-introducing previously reverted work — a common source of regressions and review churn the no-checkout claude --print reviewer cannot spot at a glance.

Closes #1696.

Signals (pure; only the request the engine already has — no repo checkout)

• explicit-revert — revert/rollback/re-introduce language in the PR title or body, including GitHub's Revert "…" titles (captures the reverted subject) and reverts commit <sha> (captures the sha).
• symmetric-churn — a file whose diff removes lines that re-appear as additions (distinct-line overlap ≥ 3 and ≥ half the larger side) — the textual fingerprint of a revert / re-introduce. Ordinary mostly-new or mostly-deleted edits are not flagged.

Changes (all within review-enrichment/)

• src/analyzers/revert-recurrence.ts — new scanRevertRecurrence(req) (fail-safe: [] on empty input).
• src/types.ts — RevertRecurrenceFinding + revertRecurrence? on BriefFindings.
• src/brief.ts — register the analyzer.
• src/render.ts — a dedicated "Revert / re-introduce recurrence" brief section.
• test/revert-recurrence.test.ts — explicit titles/bodies, reverts commit <sha>, free-text rollback, symmetric churn (incl. ignoring +++/--- headers), non-revert edits, empty input, and the rendered section.

Acceptance criteria

• Detects explicit revert titles/bodies
• Flags symmetric churn patterns in diff hunks
• Fail-safe: returns [] on empty input
• Brief renders a dedicated revert-recurrence section when findings exist

Validation

• npm --prefix review-enrichment test (build + sourcemap validation + node --test) → 165 tests pass.
• Change is isolated to the review-enrichment/ package (in wantedPaths); src/** does not import it, so the root typecheck/coverage/workers/UI gate is unaffected, and there is no src/** Codecov-patch surface.

[loopover-orb]

Warning

🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨🟨

⏸️ Gittensory review result - manual review recommended

_{Review updated: 2026-06-29 21:52:11 UTC}

5 files · 1 AI reviewer · no blockers · readiness 55/100 · CI green · dirty

⏸️ Suggested Action - Manual Review

Review summary
This change adds a REES analyzer for explicit revert language and same-file symmetric churn, wires it into the brief builder, renders a dedicated section, and covers the main intended paths in tests. The implementation is coherent and CI passed; the main maintainability concern is that the rendered explicit-revert reason can carry raw PR-title/body-derived text into the prompt brief instead of using the renderer’s existing escaping helpers.

Nits — 6 non-blocking

• nit: review-enrichment/src/render.ts:267 renders item.reason directly, so explicit-revert subjects parsed from PR title/body should be escaped with promptText or represented via safeCodeSpan before entering the prompt brief.
• nit: review-enrichment/src/analyzers/revert-recurrence.ts:44 trims diff lines before comparing them, which makes whitespace-only indentation changes look like identical removed/re-added lines; document that choice or compare a normalized-but-not-fully-trimmed body if indentation matters.
• nit: review-enrichment/src/analyzers/revert-recurrence.ts:9 caps symmetric-churn scanning to the first 50 files without surfacing truncation, so large PRs can silently skip later matching files.
• In review-enrichment/src/render.ts:267, render explicit revert subjects as escaped structured fields instead of trusting the preformatted reason string.
• In review-enrichment/src/analyzers/revert-recurrence.ts:44, add a test for indentation-only line changes so the distinct-line normalization behavior is intentional.
• Readiness score is below the configured threshold — Use the readiness panel as advisory maintainer context; the score does not block this PR.

Signal	Result	Evidence
Code review	✅ No blockers	1 reviewer
Linked issue	✅ Linked	#1696
Related work	⚠️ 3 scoped overlaps	Top overlaps are listed below; lower-confidence bulk is hidden.
Change scope	❌ 8/20	High review scope from cached public metadata (size label size:L; 1 linked issue).
Validation posture	❌ 5/25	Preflight is holding this PR; address the blocker before review.
Contributor workload	✅ 10/10	Author activity: 29 registered-repo PR(s), 16 merged, 0 issue(s).
Contributor context	✅ Confirmed Gittensor contributor	jeffrey701; Gittensor profile; 29 PR(s), 0 issue(s).
Gate result	✅ Passing	No configured blocker found.

Review context

• Author: jeffrey701
• Role context: outside_contributor
• Public audience mode: oss maintainer
• Lane context: Repository registration is not available in the local Gittensory cache.
• Public profile languages: Clojure, TypeScript
• Official Gittensor activity: 29 PR(s), 0 issue(s).
• Related work: Items reference the same linked issue feat(enrichment): revert-recurrence detector for review brief #1696. (issue #1696)
• Related work: Open PR work references issue feat(enrichment): revert-recurrence detector for review brief #1696. (issue #1696)
• Related work: Items reference the same linked issue feat(enrichment): Heavy-dependency-for-trivial-use detector #1505. (issue #1505, PR #1702)
• Additional title-only matches omitted; title-only overlap does not block.

Contributor next steps

• Review top overlaps.
• Add a concise scope and risk note.
• Fix the blocker.
• Triage stale or unlinked PRs.
• Refresh registry data or choose a registered active repo.
• Check active issues and PRs before submitting.

Signal definitions

• Related work = same linked issue, overlapping active PRs, or title/path similarity.
• Change scope = cached public metadata such as size labels, draft state, and review-burden hints.
• Validation posture = whether the PR provides enough public validation/test evidence for maintainer review.
• Contributor workload = public contributor activity and cleanup pressure, not a repo-wide quality failure.
• Contributor context = public GitHub/Gittensor identity context; non-Gittensor status is not a blocker.

_{🟩 Safe / merged · 🟦 Advisory · 🟨 Held for review · 🟥 Blocked / closed}

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Checked by Gittensory, a quiet PR intelligence layer for OSS maintainers.

• Re-run Gittensory review

[JSONbored]

The PR itself is valid/no problems, but there are now merge conflicts (previously submitted PR was merged that touched the same files).

This branch has conflicts that must be resolved
Use the [web editor](https://github.com/JSONbored/gittensory/pull/1753/conflicts) or the command line to resolve conflicts before continuing.

review-enrichment/src/brief.ts
review-enrichment/src/render.ts
review-enrichment/src/types.ts

Closing.