diff --git a/AGENTS.md b/AGENTS.md
index 2bd32b4dc..92dbcc403 100644
--- a/AGENTS.md
+++ b/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.
diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 2c555752b..1e9cbde0d 100644
--- a/ARCHITECTURE.md
+++ b/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.
diff --git a/CHANGELOG.d/2.55.0-leftover-map-compare-unexplained-share.md b/CHANGELOG.d/2.55.0-leftover-map-compare-unexplained-share.md
new file mode 100644
index 000000000..57d19892c
--- /dev/null
+++ b/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.
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5cffe6075..524e9a4c1 100644
--- a/CHANGELOG.md
+++ b/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.
diff --git a/CLAUDE.md b/CLAUDE.md
index a4d4ece4e..c86ebcb45 100644
--- a/CLAUDE.md
+++ b/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.
diff --git a/backend/app/report_ingestion.py b/backend/app/report_ingestion.py
index 58c6c2dc4..b4bfb3187 100644
--- a/backend/app/report_ingestion.py
+++ b/backend/app/report_ingestion.py
@@ -1052,7 +1052,7 @@ async def fetch_period_comparison(
f"""
select lp.grouping_kind, lp.grouping_key, lp.pair_kind, lp.post_id,
lp.criterion_code, lp.leftover_distance, lp.leftover_residual,
- lp.leftover_map_reconstruction,
+ lp.leftover_map_reconstruction, lp.leftover_map_unexplained_share,
p.post_title, p.visibility_code, p.corporate_entity_id,
({_SOURCE_CONTEXT_PRESENT_SQL}) as has_real_source_context
from report_leftover_pair lp
@@ -1138,6 +1138,11 @@ async def fetch_period_comparison(
if pair["leftover_map_reconstruction"] is None
else float(pair["leftover_map_reconstruction"])
),
+ "leftover_map_unexplained_share": (
+ None
+ if pair["leftover_map_unexplained_share"] is None
+ else float(pair["leftover_map_unexplained_share"])
+ ),
"visibility_code": pair["visibility_code"],
"corporate_entity_id": str(pair["corporate_entity_id"]),
"has_real_source_context": bool(pair["has_real_source_context"]),
diff --git a/backend/tests/test_api.py b/backend/tests/test_api.py
index 95431c425..e3590a16c 100644
--- a/backend/tests/test_api.py
+++ b/backend/tests/test_api.py
@@ -5860,6 +5860,19 @@ def test_seed_period_report_surfaces_on_get_reports(client, demo_analyst_token,
or isinstance(pair["leftover_map_reconstruction"], (int, float))
for pair in leftover_thread.get("leftover_pairs", [])
)
+ assert all(
+ "leftover_map_unexplained_share" in pair
+ for pair in leftover_thread.get("leftover_pairs", [])
+ )
+ assert any(
+ pair["leftover_map_unexplained_share"] is not None
+ for pair in leftover_thread.get("leftover_pairs", [])
+ )
+ assert all(
+ pair["leftover_map_unexplained_share"] is None
+ or isinstance(pair["leftover_map_unexplained_share"], (int, float))
+ for pair in leftover_thread.get("leftover_pairs", [])
+ )
def test_seed_period_report_includes_fixture_event_lineage_posts(
diff --git a/backend/tests/test_report_ingestion_unexplained_share.py b/backend/tests/test_report_ingestion_unexplained_share.py
new file mode 100644
index 000000000..0c6f6dff3
--- /dev/null
+++ b/backend/tests/test_report_ingestion_unexplained_share.py
@@ -0,0 +1,48 @@
+"""Regression for persisted grouping-comparison unexplained-share transport."""
+
+from __future__ import annotations
+
+import asyncio
+from decimal import Decimal
+
+from backend.app import report_ingestion
+
+
+class _ComparisonConnection:
+ """Minimal asyncpg-compatible read boundary for one comparison row."""
+
+ async def fetch(self, query: str, *_args: object) -> list[dict[str, object]]:
+ if "from report_period_score" in query:
+ return [{"grouping_kind": "thread_group", "grouping_key": "synthetic-thread", "mean_theta": 0.1, "post_count": 2, "link_method": "synthetic"}]
+ if "from report_member_score" in query:
+ return []
+ if "from report_leftover_pair" in query:
+ assert "lp.leftover_map_unexplained_share" in query, "leftover_map_unexplained_share is absent from comparison SELECT"
+ common = {
+ "grouping_kind": "thread_group",
+ "grouping_key": "synthetic-thread",
+ "post_id": "00000000-0000-0000-0000-000000000001",
+ "post_title": "Synthetic comparison post",
+ "criterion_code": "synthetic_criterion",
+ "leftover_distance": 0.5,
+ "leftover_residual": 0.4,
+ "leftover_map_reconstruction": Decimal("0.25"),
+ "visibility_code": "public",
+ "corporate_entity_id": "00000000-0000-0000-0000-000000000002",
+ "has_real_source_context": False,
+ }
+ return [
+ {**common, "pair_kind": "closest", "leftover_map_unexplained_share": Decimal("0.02")},
+ {**common, "pair_kind": "farthest", "leftover_map_unexplained_share": None},
+ ]
+ if "from report_leftover_map_coverage" in query or "from report_leftover_map_axis" in query:
+ return []
+ raise AssertionError(f"unexpected comparison query: {query}")
+
+
+def test_fetch_period_comparison_transports_persisted_unexplained_share() -> None:
+ """Persisted finite values reach the read model while SQL NULL remains unknown."""
+ payload = asyncio.run(report_ingestion.fetch_period_comparison(_ComparisonConnection(), "2026-W02")) # type: ignore[arg-type]
+ pairs = payload[0]["leftover_pairs"]
+ assert pairs[0]["leftover_map_unexplained_share"] == 0.02
+ assert pairs[1]["leftover_map_unexplained_share"] is None
diff --git a/docs/adr/0369-leftover-map-compare-unexplained-share.md b/docs/adr/0369-leftover-map-compare-unexplained-share.md
new file mode 100644
index 000000000..ce851b826
--- /dev/null
+++ b/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 period-report pair model persists `leftover_map_unexplained_share` (`s = U² / R²`) for authorized leftover pairs, but exact #828's grouping-comparison read path omits that field, so the frontend cannot receive it from `GET /api/reports/compare/{period_code}`. 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 accessibility test must RED while the parent name omits `U²/R² 0.02`, then GREEN after only the accessible-name/duplicate-badge fix. The transport regression must independently RED while the comparison SELECT omits the persisted field, then GREEN without deriving or clamping it. A real authenticated PostgreSQL/Keycloak/Valkey `GET /api/reports/compare/2026-W02` acceptance must prove the persisted key/value reaches authorized leftover pairs. 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.
diff --git a/docs/product-technical-gap-baseline.md b/docs/product-technical-gap-baseline.md
index 6a0bc0295..7ff09f08e 100644
--- a/docs/product-technical-gap-baseline.md
+++ b/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.
diff --git a/frontend/package.json b/frontend/package.json
index 52298d5f8..228735341 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,7 +1,7 @@
{
"name": "frontend",
"private": true,
- "version": "2.54.0",
+ "version": "2.55.0",
"type": "module",
"scripts": {
"dev": "vite",
diff --git a/frontend/src/App.test.tsx b/frontend/src/App.test.tsx
index 6768f4a0e..3230225df 100644
--- a/frontend/src/App.test.tsx
+++ b/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"),
diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index d291e1f55..863999640 100644
--- a/frontend/src/App.tsx
+++ b/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 (
) : null}
+ {unexplainedShare ? (
+
+ {unexplainedShare}
+
+ ) : null}
);
diff --git a/frontend/src/i18n.test.ts b/frontend/src/i18n.test.ts
index 582d0da33..8597babd7 100644
--- a/frontend/src/i18n.test.ts
+++ b/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",
diff --git a/frontend/src/i18n.ts b/frontend/src/i18n.ts
index 11745c611..ee6da0b6b 100644
--- a/frontend/src/i18n.ts
+++ b/frontend/src/i18n.ts
@@ -276,6 +276,7 @@ const TRANSLATIONS: Partial>> = {
"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>> = {
"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>> = {
"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>> = {
"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",
diff --git a/frontend/src/leftoverMapUnexplainedShare.test.ts b/frontend/src/leftoverMapUnexplainedShare.test.ts
index a5ce71272..1a369ca1d 100644
--- a/frontend/src/leftoverMapUnexplainedShare.test.ts
+++ b/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",
+ );
+ });
});
diff --git a/frontend/src/leftoverMapUnexplainedShare.ts b/frontend/src/leftoverMapUnexplainedShare.ts
index 5189471f4..4a21400db 100644
--- a/frontend/src/leftoverMapUnexplainedShare.ts
+++ b/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 {
diff --git a/lineageweave/__init__.py b/lineageweave/__init__.py
index 2c9bae6e7..15a8d1d08 100644
--- a/lineageweave/__init__.py
+++ b/lineageweave/__init__.py
@@ -130,4 +130,4 @@
"serialize_lineage_analysis_result",
]
-__version__ = "2.54.0"
+__version__ = "2.55.0"
diff --git a/pyproject.toml b/pyproject.toml
index eb1f2076d..61be353ce 100644
--- a/pyproject.toml
+++ b/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" }