feat(reports): preserve grouping comparison reconstruction for serialized successor

AGENTS.md

@@ -538,3 +538,5 @@ closed-world data-validation boundary for DB-to-RDF projections and is
 published beside the ontology.
 
 ADR 0294 keeps grouping-comparison incomplete-item coverage in the LineageWeave read-model boundary: consume only authorization-filtered persisted coverage for a full grouping, omit partial visibility, and never recompute psychometrics in the client.
+
+ADR 0295 keeps grouping-comparison reconstruction in the LineageWeave read-model/UI boundary: format only persisted `R̂`, expose the value in the pair button accessible name, and never derive psychometric reconstruction from UI-visible proxies.

ARCHITECTURE.md

@@ -1091,3 +1091,5 @@ through the unchanged, lock-free similarity-matching fast path; only
 the rare creation branch serializes.
 
 ADR 0294 adds persisted incomplete-item coverage to grouping comparison presentation while the API remains the full-group visibility authority; the frontend formats only an admitted persisted count.
+
+ADR 0295 adds persisted `R̂` to grouping-comparison pair buttons. The explicit button accessible name carries the reconstruction label/value; the visible duplicate badge is presentation-only. Psychometric computation remains owned by fast-mlsirm.

CHANGELOG.d/2.52.0-leftover-map-compare-reconstruction.md

@@ -0,0 +1,5 @@
+## 2.52.0 — Grouping comparison leftover-map reconstruction
+
+- Show persisted leftover-map reconstruction `R̂` on grouping-comparison pair buttons (ADR 0295).
+- Include the admitted reconstruction label/value in the button accessible name; keep the visible badge `aria-hidden` so it is not double-announced.
+- Missing or non-finite values omit only the reconstruction; do not derive `R̂` from distance, coordinates, residuals, rank, coverage, or any other proxy.

CHANGELOG.md

@@ -8,6 +8,8 @@ All notable changes to this project are documented here. Format follows
 
 ### Added
 
+- Grouping comparison leftover-pair buttons now expose persisted leftover-map reconstruction `R̂` (ADR 0295 / v2.52.0). The visible badge is decorative to accessibility APIs; the button accessible name carries the reconstruction label and value, so the explicit button `aria-label` cannot suppress the metric. Missing/non-finite `R̂` omits only that value and no client-side proxy is invented.
+
 - Grouping comparison rows now show persisted leftover-map incomplete-item count through `leftoverMapIncompleteItemCount` (ADR 0294 / v2.51.0) only for fully caller-visible persisted groupings. Partial visibility remains omitted by the API; valid zero stays visible, and the UI never derives dropped criteria from scored-minus-used.
 
 - Grouping comparison rows now show persisted leftover-map incomplete-post count through `leftoverMapIncompletePostCount` (ADR 0293 / v2.50.0) only for a fully caller-visible persisted grouping. Partial visibility omits the aggregate; valid persisted zero remains visible, and the UI never derives dropped posts from scored-minus-used.

CLAUDE.md

@@ -59,3 +59,5 @@ changing code, tests, or runtime policy rather than restating anything
 here.
 
 ADR 0294 is the Proposed grouping-comparison incomplete-item presentation contract; preserve server-side full-group visibility gating and do not infer dropped criteria in the frontend.
+
+ADR 0295 is the Proposed grouping-comparison reconstruction contract: persisted `R̂` only, no client inference, accessible-name exposure required despite the button's explicit aria-label.

docs/adr/0295-leftover-map-compare-reconstruction.md

@@ -0,0 +1,11 @@
+# ADR 0295 — Grouping comparison leftover-map reconstruction
+
+**Decision status:** Proposed
+
+## Problem
+Grouping-comparison pair rows carry persisted `leftover_map_reconstruction`, but the serialized current stack does not expose it. The historical implementation placed a reconstruction badge inside a button that already had an explicit `aria-label`; descendant text therefore did not reliably contribute to the button accessible name.
+
+## Decision
+Format only persisted `leftover_map_reconstruction` through `formatLeftoverMapReconstruction`. Render the visible `R̂` badge, mark that duplicate badge `aria-hidden`, and include the localized comparison-reconstruction label plus formatted value in the pair button accessible name. Missing or non-finite `R̂` omits only this suffix. Never reconstruct `R̂` from distance, coordinates, residuals, unexplained leftover, rank, coverage counts, or any visible-subset proxy.
+
+This is LineageWeave read-model/UI composition only; fast-mlsirm remains the psychometric owner. ADR status remains Proposed while Draft. Acceptance requires current-head hosted tests, keyboard/screen-reader/browser evidence, canonical eight-locale translation-ledger convergence, independent approval, and normal protected-branch merge.

docs/product-technical-gap-baseline.md

@@ -1393,3 +1393,7 @@ historical evidence only. The job-architecture artifact ship originally via
 ### 2026-09-07 — #825 current-parent reconstruction candidate
 
 Exact parent `#824@499d653ed6e9206249e3f3a07518ad3fc01f14bd` lacks the grouping-comparison incomplete-item note while carrying authorization-filtered persisted coverage. ADR 0294 / v2.51.0 adds that buyer-visible read-model presentation and regression. Candidate evidence is not protected-main/release evidence; current-head browser/a11y, canonical eight-locale ledger consumption, independent review, and normal protected merge remain outstanding.
+
+### 2026-09-07 — #826 exact-parent reconstruction candidate
+
+Exact parent `#825@b73b10e3079e77f3e62235b2b709dc8a3f450292` omits persisted `R̂` from grouping-comparison pair rows. ADR 0295 / v2.52.0 restores that valid read-model delta and repairs the historical accessibility defect by carrying the label/value in the button accessible name. Candidate evidence is not protected-main/release evidence; current-head browser/screen-reader/a11y, canonical eight-locale ledger consumption, independent review, and normal protected merge remain outstanding.

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "2.51.0",
+  "version": "2.52.0",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/App.test.tsx

@@ -922,6 +922,7 @@ describe("App, authenticated", () => {
                     criterion_code: "sales_lead_specificity",
                     leftover_distance: 0.12,
                     leftover_residual: 0.4,
+                    leftover_map_reconstruction: 0.248,
                   },
                 ],
                 leftover_map_coverage: {
@@ -4337,6 +4338,10 @@ describe("App, authenticated", () => {
         name: /open leftover closest pair from comparison: public post/i,
       }),
     ).toHaveTextContent("Closest leftover: Public post · sales-lead");
+    const reconstructionPair = screen.getByRole("button", {
+      name: /open leftover closest pair from comparison: public post.*leftover map comparison reconstruction R̂ \+0\.25/i,
+    });
+    expect(reconstructionPair).toHaveTextContent("R̂ +0.25");
     await waitFor(() =>
       expect(fetchMock).toHaveBeenCalledWith(
         expect.stringContaining("/api/reports/thread_group/2026-W02"),

frontend/src/App.tsx

@@ -143,6 +143,10 @@ import {
   LEFTOVER_MAP_AXIS_BADGE_SHARE,
   LEFTOVER_MAP_AXIS_BADGE_SINGULAR,
 } from "./leftoverMapAxisBadge";
+import {
+  formatLeftoverMapReconstruction,
+  LEFTOVER_MAP_COMPARE_RECONSTRUCTION_LABEL,
+} from "./leftoverMapReconstruction";
 import "./App.css";
 
 const AdminPanel = lazy(() => import("./components/AdminPanel").then((module) => ({ default: module.AdminPanel })));
@@ -4066,14 +4070,22 @@ function ReportsPanel({
                         ? "Open this post to read the criterion it sat farthest from after main effects."
                         : "Open this post to read the criterion it sat closest to after main effects.";
                     const criterion = criterionShortLabel(pair.criterion_code);
+                    const reconstruction = formatLeftoverMapReconstruction(
+                      pair.leftover_map_reconstruction,
+                    );
+                    const pairAccessibleName = `Open leftover ${pair.pair_kind} pair from comparison: ${pair.post_title} · ${criterion}${
+                      reconstruction
+                        ? ` · ${t(LEFTOVER_MAP_COMPARE_RECONSTRUCTION_LABEL)} ${reconstruction}`
+                        : ""
+                    }`;
                     return (
                       <li
                         key={`${row.grouping_kind}:${row.grouping_key}:${pair.pair_kind}:${pair.post_id}:${pair.criterion_code}`}
                         className="ticket-list-item"
                       >
                         <button
                           className="post-list-item"
-                          aria-label={`Open leftover ${pair.pair_kind} pair from comparison: ${pair.post_title} · ${criterion}`}
+                          aria-label={pairAccessibleName}
                           onClick={() =>
                             // Same promise, same landing: the badge tells the
                             // reader the criterion will be current in Post
@@ -4092,6 +4104,11 @@ function ReportsPanel({
                           </span>
                           <span className="post-badge">{nextAction}</span>
                           <span className="post-badge">d {pair.leftover_distance.toFixed(2)}</span>
+                          {reconstruction ? (
+                            <span className="post-badge" aria-hidden="true">
+                              {reconstruction}
+                            </span>
+                          ) : null}
                         </button>
                       </li>
                     );

frontend/src/i18n.test.ts

@@ -84,6 +84,7 @@ describe("i18n", () => {
     "Leftover map comparison item coverage",
     "Leftover map comparison incomplete posts",
     "Leftover map comparison incomplete items",
+    "Leftover map comparison reconstruction",
     "Leftover-map graphic item coverage",
     "Leftover map item coverage",
     "Leftover map incomplete posts",

frontend/src/i18n.ts

@@ -272,6 +272,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "Leftover map comparison item coverage": "잔여 지도 비교 기준 포함 범위",
     "Leftover map comparison incomplete posts": "잔여 지도 비교 불완전 글",
     "Leftover map comparison incomplete items": "잔여 지도 비교 불완전 기준",
+    "Leftover map comparison reconstruction": "잔여 지도 비교 재구성",
     "Leftover map item coverage": "잔여 지도 기준 포함 범위",
     "Leftover map incomplete posts": "잔여 지도 불완전 글",
     "Leftover map incomplete items": "잔여 지도 불완전 기준",
@@ -885,6 +886,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "Leftover map comparison item coverage": "残差地图比较准则覆盖范围",
     "Leftover map comparison incomplete posts": "残差地图比较不完整帖文",
     "Leftover map comparison incomplete items": "残差地图比较不完整准则",
+    "Leftover map comparison reconstruction": "残差地图比较重建",
     "Leftover map item coverage": "残差地图准则覆盖范围",
     "Leftover map incomplete posts": "残差地图不完整帖文",
     "Leftover map incomplete items": "残差地图不完整准则",
@@ -1519,6 +1521,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "Leftover map comparison item coverage": "残差マップの比較基準対象範囲",
     "Leftover map comparison incomplete posts": "残差マップの比較不完全投稿",
     "Leftover map comparison incomplete items": "残差マップの比較不完全基準",
+    "Leftover map comparison reconstruction": "残差マップの比較再構成",
     "Leftover map item coverage": "残差マップの基準対象範囲",
     "Leftover map incomplete posts": "残差マップの不完全投稿",
     "Leftover map incomplete items": "残差マップの不完全基準",
@@ -2132,6 +2135,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "Leftover map comparison item coverage": "Phạm vi so sánh tiêu chí bản đồ phần dư",
     "Leftover map comparison incomplete posts": "Bài không đầy đủ so sánh trên bản đồ phần dư",
     "Leftover map comparison incomplete items": "Tiêu chí không đầy đủ so sánh trên bản đồ phần dư",
+    "Leftover map comparison reconstruction": "Tái dựng so sánh bản đồ phần dư",
     "Leftover map item coverage": "Phạm vi tiêu chí bản đồ phần dư",
     "Leftover map incomplete posts": "Bài không đầy đủ trên bản đồ phần dư",
     "Leftover map incomplete items": "Tiêu chí không đầy đủ trên bản đồ phần dư",

frontend/src/leftoverMapReconstruction.ts

@@ -5,6 +5,9 @@ import { formatSignedLeftoverValue } from "./leftoverMapUnexplained";
 export const LEFTOVER_MAP_RECONSTRUCTION_ACTION =
   "Leftover map reconstructs R̂ {value} after IRT main effects. Open this post to read {criterion}.";
 
+export const LEFTOVER_MAP_COMPARE_RECONSTRUCTION_LABEL =
+  "Leftover map comparison reconstruction";
+
 const RECONSTRUCTION_BADGE = "R\u0302";
 
 export function formatLeftoverMapReconstruction(value: number | null | undefined): string | null {

lineageweave/__init__.py

@@ -130,4 +130,4 @@
     "serialize_lineage_analysis_result",
 ]
 
-__version__ = "2.51.0"
+__version__ = "2.52.0"

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "lineageweave"
-version = "2.51.0"
+version = "2.52.0"
 description = "Reconstructs git-branch-style lineage DAGs from scattered short records using multi-channel score fusion and LLM adjudication."
 readme = "README.md"
 license = { text = "MIT" }

tests/test_adr_0295_governance.py

@@ -0,0 +1,15 @@
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def test_reconstruction_comparison_uses_distinct_proposed_adr_0295() -> None:
+    assert (ROOT / "docs/adr/0294-leftover-map-compare-incomplete-item.md").exists()
+    path = ROOT / "docs/adr/0295-leftover-map-compare-reconstruction.md"
+    assert path.exists()
+    text = path.read_text(encoding="utf-8")
+    assert text.startswith("# ADR 0295 —")
+    assert "**Decision status:** Proposed" in text
+    assert "**Decision status:** Accepted" not in text
+    assert "accessible name" in text
+    assert "fast-mlsirm" in text