feat(reports): preserve grouping comparison unexplained-share delta for serialized successor

AGENTS.md

@@ -544,3 +544,5 @@ ADR 0295 keeps grouping-comparison reconstruction in the LineageWeave read-model
 ADR 0296 adds persisted grouping-comparison explained-leftover share `e` in the LineageWeave read-model/UI boundary: expose it in the pair button accessible name, keep the duplicate visible badge presentation-only, and never derive or clamp psychometric values.
 
 ADR 0367 exposes persisted grouping-comparison leftover-map axis share only for a fully caller-visible persisted grouping. Partial visibility returns no axis aggregate; never recompute it from visible members. Missing/non-finite share omits only the badge; persisted zero and finite negative values remain explicit.
+
+ADR 0369 adds persisted grouping-comparison `U²/R²` only as a presentation/read-model consumer on exact #828. Never derive or clamp it, never recompute it from a visible subset, and include every finite buyer-visible comparison metric in the actionable pair button accessible name.

ARCHITECTURE.md

@@ -1097,3 +1097,5 @@ ADR 0295 adds persisted `R̂` to grouping-comparison pair buttons. The explicit
 ADR 0296 adds persisted explained-leftover share `e = R̂²/R²` to grouping-comparison pair actions; the button accessible name is authoritative for assistive technology and fast-mlsirm remains psychometric owner.
 
 ADR 0367 adds persisted `leftover_map_axes` to the grouping-comparison read model under the same whole-population authorization rule as other psychometric aggregates. The UI consumes persisted `leftover_share` through `leftoverMapCompareAxisShare`; no subset recomputation or singular-value derivation is permitted.
+
+ADR 0369 composes persisted finite grouping-comparison `leftover_map_unexplained_share` into pair actions. The parent button accessible name and visual badge share one formatter result; the visual duplicate is `aria-hidden`. Authorization and psychometric ownership remain upstream/current-parent contracts.

CHANGELOG.d/2.55.0-leftover-map-compare-unexplained-share.md

@@ -0,0 +1,5 @@
+## 2.55.0 — Grouping comparison unexplained leftover share
+
+- Show persisted finite `U²/R²` on grouping-comparison leftover-pair actions through `formatLeftoverMapUnexplainedShare` (ADR 0369). Zero and values above 1 remain explicit; missing/non-finite values are omitted.
+- Include the localized persisted metric in the actionable button accessible name; hide the duplicate visual badge from the accessibility tree.
+- Never derive, clamp, or recompute psychometric truth from caller-visible subsets. Historical ADR0295/v2.52.0 is evidence only.

CHANGELOG.md

@@ -8,6 +8,8 @@ All notable changes to this project are documented here. Format follows
 
 ### Added
 
+- Grouping comparison pair actions now surface persisted finite unexplained leftover share `U²/R²` under ADR 0369 / v2.55.0, including the metric in the button accessible name and never deriving it from other psychometric values.
+
 - Grouping comparison pair buttons now expose persisted explained-leftover share `e = R̂²/R²` (ADR 0296 / v2.53.0). The visible duplicate badge is accessibility-hidden while the actionable button name includes the localized label and formatted persisted value. Missing/non-finite `e` omits only the suffix; finite zero and values above 1 remain explicit without clamping or client-side derivation.
 
 - 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.

CLAUDE.md

@@ -63,3 +63,5 @@ ADR 0294 is the Proposed grouping-comparison incomplete-item presentation contra
 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.
 
 ADR 0296 is the Proposed grouping-comparison explained-share contract: persisted `e` only, accessible-name exposure required, no client derivation or clamping.
+
+Grouping-comparison unexplained-share presentation is ADR 0369: consume persisted finite `leftover_map_unexplained_share`, never derive it, and keep its value in the actionable button accessible name.

docs/adr/0369-leftover-map-compare-unexplained-share.md

@@ -0,0 +1,26 @@
+# ADR 0369 — Persisted unexplained leftover share in grouping comparison pair actions
+
+**Decision status:** Proposed
+
+## Problem
+The grouping-comparison read model already carries persisted `leftover_map_unexplained_share` (`s = U² / R²`) for authorized leftover pairs, but exact #828 does not surface it on comparison pair actions. Historical #829 proved the buyer-visible delta but used stale ancestry/identity and put the metric only in a child badge while the parent button supplied an explicit accessible name.
+
+## Constraints
+- Consume persisted psychometric truth; never derive `s` from `U`, `R`, reconstruction, distance, geometry, rank, coverage, or other shares.
+- Missing/non-finite values are omitted. Zero and finite values above 1 remain explicit and unclamped.
+- Whole-population authorization remains current-parent authority; no visible-subset recomputation.
+- The actionable pair button and visible badge communicate the same finite persisted value.
+- Inline KO/ZH/JA/VI copy is compatibility presentation only; #922/#929/#932 remain canonical eight-locale translation-ledger authority.
+
+## Alternatives and decision
+Hiding `s` loses persisted buyer evidence. Recomputing it duplicates psychometric authority. A child-only badge fails the actionable accessible-name contract. Therefore consume persisted finite `s`, append its localized label/value to the button accessible name, and mark the duplicate visible badge `aria-hidden`.
+
+This is the serialized successor of exact #828 `7b6dbbb99a09d0523bce43c6872bbd9fa382a43a`, adopts the distinct historical #829 delta, and allocates v2.55.0. ADR0295/v2.52.0 is historical evidence only.
+
+## Verification
+The focused current-parent test must first RED while the parent name omits `U²/R² 0.02`, then GREEN after only the accessible-name/duplicate-badge fix. Full backend, frontend lint/test/build/Storybook, version parity, clean-tree authority, and non-force promotion are required. Hosted exact-product-head checks, browser/keyboard/focus/a11y evidence, and qualifying independent approval remain separate merge gates.
+
+## Evidence
+Gabriel, K. R. (1971). The biplot graphic display of matrices with application to principal component analysis. *Biometrika, 58*(3), 453–467.
+
+Jeon, M., Jin, I. H., Schweinberger, M., & Baugh, S. (2021). Mapping unobserved item–respondent interactions: A latent space item response model with interaction map. *Psychometrika, 86*(2), 378–403.

docs/product-technical-gap-baseline.md

@@ -1,5 +1,8 @@
 # Product & Technical Gap Baseline
 
+> Current serialized repair (2026-09-07): #829 consumes exact promoted #828 `7b6dbbb99a09d0523bce43c6872bbd9fa382a43a` and preserves persisted `U²/R²` comparison presentation as ADR 0369 / v2.55.0. Finite values are present in the actionable button name and visible badge; missing/non-finite values are absent; values are never derived/clamped; current-parent whole-population authorization remains intact. Historical ADR0295/v2.52.0 is evidence only. Inline five-locale copy is compatibility presentation while #922/#929/#932 remain the eight-locale translation-ledger owner path.
+
+
 > Current serialized repair (2026-09-07): #828 is reconstructed from exact #827 `0f9e9c8db37948041f39b4e68e4bbd808fa83752` as ADR 0367 / v2.54.0. The valid delta carries persisted grouping-comparison `leftover_map_axes` but exposes them only when the caller can see the entire persisted grouping population; partial visibility returns no aggregate and never recomputes psychometrics from the visible subset. Presentation consumes persisted `leftover_share` only, with zero and finite negative values explicit and missing/non-finite values omitted. Historical v2.50.0/ADR0293 identity is evidence only. Existing five-locale compatibility copy is preserved while the database-backed eight-locale translation-ledger authority remains #922/#929/#932; this Draft does not create a competing translation source.
 
 

frontend/package.json

@@ -1,7 +1,7 @@
 {
   "name": "frontend",
   "private": true,
-  "version": "2.54.0",
+  "version": "2.55.0",
   "type": "module",
   "scripts": {
     "dev": "vite",

frontend/src/App.test.tsx

@@ -928,6 +928,7 @@ describe("App, authenticated", () => {
                     leftover_residual: 0.4,
                     leftover_map_reconstruction: 0.248,
                     leftover_map_explained_share: 0.76,
+                    leftover_map_unexplained_share: 0.02,
                   },
                 ],
                 leftover_map_coverage: {
@@ -4383,6 +4384,10 @@ describe("App, authenticated", () => {
       name: /open leftover closest pair from comparison: public post.*leftover map comparison reconstruction R̂ \+0\.25.*leftover map comparison explained leftover share R̂²\/R² 0\.76/i,
     });
     expect(explainedSharePair).toHaveTextContent("R̂²/R² 0.76");
+    const unexplainedSharePair = screen.getByRole("button", {
+      name: /open leftover closest pair from comparison: public post.*leftover map comparison unexplained leftover share U²\/R² 0\.02/i,
+    });
+    expect(unexplainedSharePair).toHaveTextContent("U²/R² 0.02");
     await waitFor(() =>
       expect(fetchMock).toHaveBeenCalledWith(
         expect.stringContaining("/api/reports/thread_group/2026-W02"),

frontend/src/App.tsx

@@ -151,6 +151,10 @@ import {
   formatLeftoverMapExplainedShare,
   LEFTOVER_MAP_COMPARE_EXPLAINED_SHARE_LABEL,
 } from "./leftoverMapExplainedShare";
+import {
+  formatLeftoverMapUnexplainedShare,
+  LEFTOVER_MAP_COMPARE_UNEXPLAINED_SHARE_LABEL,
+} from "./leftoverMapUnexplainedShare";
 import {
   leftoverMapCompareAxisShare,
   LEFTOVER_MAP_COMPARE_AXIS_SHARE,
@@ -4100,6 +4104,9 @@ function ReportsPanel({
                     const explainedShare = formatLeftoverMapExplainedShare(
                       pair.leftover_map_explained_share,
                     );
+                    const unexplainedShare = formatLeftoverMapUnexplainedShare(
+                      pair.leftover_map_unexplained_share,
+                    );
                     const pairAccessibleName = `Open leftover ${pair.pair_kind} pair from comparison: ${pair.post_title} · ${criterion}${
                       reconstruction
                         ? ` · ${t(LEFTOVER_MAP_COMPARE_RECONSTRUCTION_LABEL)} ${reconstruction}`
@@ -4108,6 +4115,10 @@ function ReportsPanel({
                       explainedShare
                         ? ` · ${t(LEFTOVER_MAP_COMPARE_EXPLAINED_SHARE_LABEL)} ${explainedShare}`
                         : ""
+                    }${
+                      unexplainedShare
+                        ? ` · ${t(LEFTOVER_MAP_COMPARE_UNEXPLAINED_SHARE_LABEL)} ${unexplainedShare}`
+                        : ""
                     }`;
                     return (
                       <li
@@ -4145,6 +4156,11 @@ function ReportsPanel({
                               {explainedShare}
                             </span>
                           ) : null}
+                          {unexplainedShare ? (
+                            <span className="post-badge" aria-hidden="true">
+                              {unexplainedShare}
+                            </span>
+                          ) : null}
                         </button>
                       </li>
                     );

frontend/src/i18n.test.ts

@@ -88,6 +88,7 @@ describe("i18n", () => {
     "leftover map comparison axis {axis} {share}%",
     "Leftover map comparison reconstruction",
     "Leftover map comparison explained leftover share",
+    "Leftover map comparison unexplained leftover share",
     "Leftover-map graphic item coverage",
     "Leftover map item coverage",
     "Leftover map incomplete posts",

frontend/src/i18n.ts

@@ -276,6 +276,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison axis {axis} {share}%": "잔여 지도 비교 축 {axis} {share}%",
     "Leftover map comparison reconstruction": "잔여 지도 비교 재구성",
     "Leftover map comparison explained leftover share": "잔여 지도 비교 설명 잔여 비율",
+    "Leftover map comparison unexplained leftover share": "잔여 지도 비교 미설명 잔여 비율",
     "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",
@@ -893,6 +894,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison axis {axis} {share}%": "残差地图比较轴 {axis} {share}%",
     "Leftover map comparison reconstruction": "残差地图比较重建",
     "Leftover map comparison explained leftover share": "残差地图比较已解释残差占比",
+    "Leftover map comparison unexplained leftover share": "残差地图比较未解释残差占比",
     "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",
@@ -1531,6 +1533,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison axis {axis} {share}%": "残差マップの比較軸 {axis} {share}%",
     "Leftover map comparison reconstruction": "残差マップの比較再構成",
     "Leftover map comparison explained leftover share": "残差マップの比較説明済み残差比率",
+    "Leftover map comparison unexplained leftover share": "残差マップの比較未説明残差比率",
     "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",
@@ -2148,6 +2151,7 @@ const TRANSLATIONS: Partial<Record<Locale, Record<string, string>>> = {
     "leftover map comparison axis {axis} {share}%": "trục so sánh bản đồ phần dư {axis} {share}%",
     "Leftover map comparison reconstruction": "Tái dựng so sánh bản đồ phần dư",
     "Leftover map comparison explained leftover share": "Tỷ phần phần dư được giải thích khi so sánh bản đồ phần dư",
+    "Leftover map comparison unexplained leftover share": "Tỷ phần phần dư chưa được giải thích khi 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/leftoverMapUnexplainedShare.test.ts

@@ -1,5 +1,8 @@
 import { describe, expect, it } from "vitest";
-import { formatLeftoverMapUnexplainedShare } from "./leftoverMapUnexplainedShare";
+import {
+  formatLeftoverMapUnexplainedShare,
+  LEFTOVER_MAP_COMPARE_UNEXPLAINED_SHARE_LABEL,
+} from "./leftoverMapUnexplainedShare";
 
 describe("formatLeftoverMapUnexplainedShare", () => {
   it("names leftover-map unexplained leftover share without inventing a leftover score", () => {
@@ -15,4 +18,10 @@ describe("formatLeftoverMapUnexplainedShare", () => {
     expect(formatLeftoverMapUnexplainedShare(Number.POSITIVE_INFINITY)).toBeNull();
     expect(formatLeftoverMapUnexplainedShare(Number.NEGATIVE_INFINITY)).toBeNull();
   });
+
+  it("keeps the grouping comparison unexplained leftover share label distinct", () => {
+    expect(LEFTOVER_MAP_COMPARE_UNEXPLAINED_SHARE_LABEL).toBe(
+      "Leftover map comparison unexplained leftover share",
+    );
+  });
 });

frontend/src/leftoverMapUnexplainedShare.ts

@@ -3,6 +3,9 @@
 export const LEFTOVER_MAP_UNEXPLAINED_SHARE_ACTION =
   "Leftover map leaves unexplained leftover share {value} of raw residual after IRT main effects. Open this post to read {criterion}.";
 
+export const LEFTOVER_MAP_COMPARE_UNEXPLAINED_SHARE_LABEL =
+  "Leftover map comparison unexplained leftover share";
+
 export function formatLeftoverMapUnexplainedShare(
   value: number | null | undefined,
 ): string | null {

lineageweave/__init__.py

@@ -130,4 +130,4 @@
     "serialize_lineage_analysis_result",
 ]
 
-__version__ = "2.54.0"
+__version__ = "2.55.0"

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "lineageweave"
-version = "2.54.0"
+version = "2.55.0"
 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" }