feat(#3806): canonize the Review Dispositions Ledger contract (#4345)

* test(#3806): add parity tests for the Review Dispositions Ledger contract

Failing-first: asserts references/planner-reviews.md, workflows/plan-phase.md,
and agents/gsd-plan-checker.md agree on a single canonical "Review Dispositions
Ledger" heading, its round-scoping, L##@{sha} anchor format, and append-only
supersession rule. These fail until the canon and its two references are added.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* feat(#3806): canonize the Review Dispositions Ledger contract

Promote the existing planner-reviews.md Step 4 return-payload tables
(Review Feedback Addressed/Deferred) into a canonical `## Review
Dispositions Ledger` PLAN.md section, stated once in planner-reviews.md
and referenced (not restated) from plan-phase.md's
<review_incorporation_contract> and gsd-plan-checker.md's Review
Incorporation dimension. Adds round-scoping (`### Round {N} —
{REVIEWS_sha}`), a `L##@{sha}` line-anchor format so a REVIEWS.md
reference survives the file being rewritten each round, and an
append-only supersession rule. Scoped to part 1 only per the
maintainer's approved-feature verdict — the deterministic lint/check
verb (part 2) is explicitly deferred to a follow-up.

Also: ADR-3806 recording the decision, a docs/features/ fragment
(FEATURES.md is generated), and a changeset fragment.

Closes #3806

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* fix(#3806): fenced-example count bug and lint findings from review

- tests/plan-review-convergence.test.cjs: the "heading exactly once"
  test counted the canonical heading text globally, so it also matched
  the illustrative fenced-code example in planner-reviews.md that shows
  the same heading as sample content, always failing 2 !== 1. Rewritten
  as a bounded line scanner that skips fenced blocks (found by an
  isolated adversarial review pass). Also bounded an unbounded regex
  quantifier over readFileSync content flagged by
  local/no-unbounded-quantifier.
- docs/features/review-dispositions-ledger.md: match house fragment
  style (bold-lead paragraphs, not #### headings) per the Standards-axis
  review; regenerated docs/FEATURES.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* fix(#3806): fit reference-cite fix within size hard caps; ack growth

Trims the plan-phase.md / gsd-plan-checker.md reference-cite text to a
single short clause pointing at gsd-core/references/planner-reviews.md
(also fixes the bare `references/planner-reviews.md` cite the #3576
shipped-reference-cites gate rejects), bringing both files back under
their SIZE hard caps and the plan-phase.md phase6 shrink-only baseline.
Both files still grow slightly versus origin/next, acknowledged below
per ADR-2719's emitted-drift-ack contract.

Emitted-Drift-Ack-Growth: gsd-plan-checker.md — adds a short pointer (in the existing Review Incorporation bullet) to the canonical Review Dispositions Ledger location (#3806); stays within the LARGE hard cap.
Emitted-Drift-Ack-Growth: plan-phase.md — adds a short pointer (in the existing review_incorporation_contract bullet) to the canonical Review Dispositions Ledger location (#3806); stays under the XL hard cap and the phase6 shrink-only baseline.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* fix(#3806): correct malformed Emitted-Drift-Ack-Growth trailer block

The previous commit's two Emitted-Drift-Ack-Growth trailers were
separated from the Co-Authored-By trailer by a blank line, so git's
own trailer parser (which tests/helpers/emitted-runtime.cjs reads via
`%(trailers:key=...)`) only recognized the last contiguous block
(Co-Authored-By) and treated the Ack-Growth lines as ordinary body
text — invisible to the emitted-attribution gate, not malformed data.
Restating them here as one contiguous trailer block, git log over the
PR range aggregates trailers from every commit, so this is additive.
Emitted-Drift-Ack-Growth: gsd-plan-checker.md — adds a short pointer (in the existing Review Incorporation bullet) to the canonical Review Dispositions Ledger location (#3806); stays within the LARGE hard cap.
Emitted-Drift-Ack-Growth: plan-phase.md — adds a short pointer (in the existing review_incorporation_contract bullet) to the canonical Review Dispositions Ledger location (#3806); stays under the XL hard cap and the phase6 shrink-only baseline.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* fix(#3806): isolate the ack-trailer paragraph as its own trailer block

Git's trailer parser requires the trailer paragraph to be the message's
final paragraph, preceded by a blank line, and to contain nothing but
trailer-shaped lines. The prior commit's blank line before the trailer
lines was missing, which folded the leading Emitted-Drift-Ack-Growth
lines into an ordinary prose paragraph.

Emitted-Drift-Ack-Growth: gsd-plan-checker.md — adds a short pointer (in the existing Review Incorporation bullet) to the canonical Review Dispositions Ledger location (#3806); stays within the LARGE hard cap.
Emitted-Drift-Ack-Growth: plan-phase.md — adds a short pointer (in the existing review_incorporation_contract bullet) to the canonical Review Dispositions Ledger location (#3806); stays under the XL hard cap and the phase6 shrink-only baseline.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* docs(#3806): backfill PR #4345 into changeset and ADR

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

---------

Co-authored-by: sim <sim@local>
Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>

docs/features/review-dispositions-ledger.md

@@ -0,0 +1,38 @@
+---
+id: 3806
+title: Review Dispositions Ledger
+group: Planning Features
+---
+
+**Purpose:** Reviews-mode planning (`/gsd-plan-phase {N} --reviews`) has required every current
+actionable REVIEWS.md finding to be incorporated into PLAN.md or explicitly deferred/rejected
+there since v1.5.0 (#724/#728). Nothing canonized *where* in PLAN.md, *what shape*, or how a
+REVIEWS.md line reference survives the next round rewriting the file wholesale. Two
+independently-invented, mutually incompatible disposition formats were observed across two
+consecutive rounds of the same phase, each written by a different planner subagent instance
+improvising from prose alone.
+
+**Behavior:** The existing return-payload tables from `references/planner-reviews.md` Step 4 —
+`### Review Feedback Addressed` / `### Review Feedback Deferred` — are now the canonical
+**Review Dispositions Ledger**, promoted verbatim in shape into the affected PLAN.md itself under
+a `## Review Dispositions Ledger` heading. Each reviews-mode round gets its own
+`### Round {N} — {REVIEWS_sha}` subsection, where `{REVIEWS_sha}` is the commit that wrote that
+round's REVIEWS.md snapshot (`workflows/review.md` already commits REVIEWS.md as its own commit).
+A REVIEWS.md line reference cites `L##@{REVIEWS_sha}`; a bare line number is non-conforming. The
+ledger is append-only — a later round adds a new row naming what it supersedes rather than editing
+or deleting an earlier round's tables.
+
+The contract is stated once, in `references/planner-reviews.md`; `workflows/plan-phase.md`'s
+`<review_incorporation_contract>` and `agents/gsd-plan-checker.md`'s Review Incorporation dimension
+both reference it by name rather than restating it, guarded by a parity test
+(`tests/plan-review-convergence.test.cjs`) that fails if the three drift apart.
+
+`{Concern}`/`{Reason}` stay free text — the reviewer roster is capability-owned and open to
+third-party additions, so no closed reviewer/severity enum is introduced.
+
+**Known limits:** No lint or check verb enforces this shape yet — a follow-up (tracked as part 2
+of #3806) will add deterministic enforcement once a migration story for the two pre-existing ad-hoc
+formats already in the wild is decided. Legacy PLAN.md content written before this convention is
+not migrated or flagged.
+
+**Reference:** [ADR-3806](adr/3806-review-dispositions-ledger.md) · [Cross-AI Peer Review](#42-cross-ai-peer-review)