feat(reports): leftover-map distance on pair segments (v2.28.0)

AGENTS.md

@@ -273,7 +273,7 @@ stops startup instead of leaving a healthy-looking partial schema, and
 application code must not compensate for a missing table.
 
 Period leftover pairs (ADR 0017 / 0018 / 0048 / 0049 / 0119 / 0158 / 0162 /
-0163 / 0164 / 0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270) are computed in `lineageweave/leftover_pairs.py` from the
+0163 / 0164 / 0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270 / 0271) are computed in `lineageweave/leftover_pairs.py` from the
 residual after a real GRM/GPCM score, never invented. Distances are
 Euclidean on the two-dimensional Gabriel leftover map; missing cells stay
 out of the factorization. Closest and farthest post–criterion pairs
@@ -298,7 +298,10 @@ that axis badge and keeps the existing leftover-map axis text. ADR 0270
 ticks leftover-map axes at the origin and at each unique finite
 persisted `ξ` / `ζ` coordinate so the pair-row badge matches the
 plot; rank-0 unused axes name only `0` and do not invent drawing-scale
-ticks. When `R`, `R̂`, `U`, `x`,
+ticks. ADR 0271 captions leftover-map pair segments with persisted
+leftover-map distance `d` so the pair-row badge matches the graphic;
+a missing or non-finite `d` omits that segment caption and does not
+invent `d` from plotted coordinates. When `R`, `R̂`, `U`, `x`,
 `s`, and `e` are finite, `e + s + x = 1`. When coordinates,
 reconstruction, and distance are finite, `R̂ = ξ · ζ` and
 `d = ‖ξ − ζ‖`. The pairs sit above the member

ARCHITECTURE.md

@@ -637,7 +637,7 @@ information at the group's mean θ (Lord, 1980 max-info CAT). Rankings
 persist to `report_item_information`. After those IRT main effects,
 residual SVD leftover pairs on two Gabriel axes (Jeon et al., 2021;
 ADR 0017 / 0048 / 0049 / 0119 / 0148 / 0158 / 0162 / 0163 / 0164 / 0168 /
-0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270) persist to `report_leftover_pair` with signed residual `R`,
+0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270 / 0271) persist to `report_leftover_pair` with signed residual `R`,
 observed `Y`, expected `E[Y|θ, item]`, full leftover-map rank, unexplained
 leftover, ADR 0201 reconstruction evidence, ADR 0185 cross-share evidence,
 ADR 0233 unexplained leftover share `s`, ADR 0266 explained leftover
@@ -646,7 +646,8 @@ ADR 0268 draws those persisted coordinates as the leftover-map graphic
 display above the pair buttons. ADR 0269 captions leftover-map axes 1
 and 2 with persisted leftover-map axis share. ADR 0270 ticks those
 leftover-map axes at persisted `ξ` / `ζ` coordinates so the pair-row
-badge matches the plot. Click a post marker or a pair button
+badge matches the plot. ADR 0271 captions leftover-map pair segments
+with persisted leftover-map distance `d`. Click a post marker or a pair button
 opens that post. Those ADRs are the normative mathematical, storage, and
 display contracts. Leftover-map axis share
 (Gabriel inertia of residual SVD axes 1 and 2; ADR 0148) persists to

CHANGELOG.d/2.28.0-leftover-map-segment-distance.md

@@ -0,0 +1,12 @@
+## 2.28.0 — Leftover-map distance on graphic-display pair segments
+
+- Caption leftover-map graphic-display pair segments with persisted
+  leftover-map distance `d` (ADR 0271). After `make seed`, closest and
+  farthest leftover pairs sit above the member list with the Gabriel
+  biplot of already-named coordinates, leftover-map axis share when
+  finite, axis ticks that match `ξ (x, y) ζ (x, y)` on the pair row,
+  and pair segments that match `d` on the pair row; click a post
+  marker or a pair button opens that post. A missing or non-finite
+  `d` omits that segment caption. Do not invent `d` from plotted
+  coordinates. Never invent a leftover score. Never invent a theta.
+  No new columns.

CHANGELOG.md

@@ -8,6 +8,17 @@ All notable changes to this project are documented here. Format follows
 
 ### Added
 
+- Period leftover pairs now caption leftover-map graphic-display pair
+  segments with persisted leftover-map distance `d` (ADR 0271 /
+  v2.28.0). After `make seed`, closest and farthest leftover pairs sit
+  above the member list with the Gabriel biplot of already-named
+  coordinates, leftover-map axis share when finite, axis ticks that
+  match `ξ (x, y) ζ (x, y)` on the pair row, and pair segments that
+  match `d` on the pair row; click a post marker or a pair button
+  opens that post. A missing or non-finite `d` omits that segment
+  caption. Do not invent `d` from plotted coordinates. Never invent a
+  leftover score or a theta. No new columns.
+
 - Period leftover pairs now caption leftover-map graphic-display axes
   with persisted leftover-map coordinate ticks (ADR 0270 / v2.27.0).
   After `make seed`, closest and farthest leftover pairs sit above the

CLAUDE.md

@@ -49,7 +49,7 @@ cutoff. Global Ask optional `knowledge_cutoff` uses the same cover
 
 Create/start endpoint rules (ADR 0017 / 0021), tie-vs-miss similarity
 (ADR 0026), R&R catalog ids (ADR 0019 / 0027), leftover pairs
-(ADR 0048–0164 / 0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270), occupational construct catalog search
+(ADR 0048–0164 / 0182 / 0185 / 0201 / 0233 / 0266 / 0267 / 0268 / 0269 / 0270 / 0271), occupational construct catalog search
 (ADR 0257), the text-channel embedding swap and cosine
 clamp (ADR 0190), per-edge channel-score persistence (ADR 0195),
 token-backed status notices (ADR 0220),

docs/adr/0048-persist-lsirm-leftover-pairs.md

@@ -13,7 +13,8 @@
 [ADR 0267](0267-leftover-map-coordinates.md) (leftover-map coordinates ξ, ζ);
 [ADR 0268](0268-leftover-map-graphic-display.md) (leftover-map graphic display);
 [ADR 0269](0269-leftover-map-axis-share-plot.md) (leftover-map axis share on the graphic display);
-[ADR 0270](0270-leftover-map-coordinate-ticks.md) (leftover-map coordinate ticks)
+[ADR 0270](0270-leftover-map-coordinate-ticks.md) (leftover-map coordinate ticks);
+[ADR 0271](0271-leftover-map-segment-distance.md) (leftover-map distance on pair segments)
 
 ## Context
 
@@ -71,7 +72,9 @@ from the pair row. ADR 0268 draws those persisted coordinates as the
 leftover-map graphic display; it adds no columns. ADR 0269 captions
 those leftover-map axes with persisted leftover-map axis share; it
 adds no columns. ADR 0270 ticks leftover-map axes at persisted `ξ` /
-`ζ` coordinates; it adds no columns.
+`ζ` coordinates; it adds no columns. ADR 0271 captions leftover-map
+pair segments with persisted leftover-map distance `d`; it adds no
+columns.
 
 Cascade the rows with `report_period_score`. A leftover post must
 also be a `report_member_score` row, and the leftover criterion

docs/adr/0049-leftover-pair-report-ui.md

@@ -14,7 +14,8 @@
 [ADR 0267](0267-leftover-map-coordinates.md) (leftover-map coordinates ξ, ζ);
 [ADR 0268](0268-leftover-map-graphic-display.md) (leftover-map graphic display);
 [ADR 0269](0269-leftover-map-axis-share-plot.md) (leftover-map axis share on the graphic display);
-[ADR 0270](0270-leftover-map-coordinate-ticks.md) (leftover-map coordinate ticks)
+[ADR 0270](0270-leftover-map-coordinate-ticks.md) (leftover-map coordinate ticks);
+[ADR 0271](0271-leftover-map-segment-distance.md) (leftover-map distance on pair segments)
 
 ## Context
 
@@ -41,7 +42,8 @@ coordinates exist, the leftover-map graphic display of those positions
 sits above the pair buttons (ADR 0268); click a post marker to open
 that post. Leftover-map axis share captions those leftover-map axes
 when finite (ADR 0269). Leftover-map axis ticks name persisted `ξ` /
-`ζ` coordinates (ADR 0270). The pair renders every available finite measurement.
+`ζ` coordinates (ADR 0270). Pair segments name persisted leftover-map
+distance `d` (ADR 0271). The pair renders every available finite measurement.
 The next action uses the first available value in the priority below; no
 amendment hides another badge, rank 0
 explicitly names no leftover structure, and unexplained leftover names
@@ -72,6 +74,8 @@ Leftover-map axis share on the graphic display is
 [ADR 0269](0269-leftover-map-axis-share-plot.md).
 Leftover-map coordinate ticks are
 [ADR 0270](0270-leftover-map-coordinate-ticks.md).
+Leftover-map distance on pair segments is
+[ADR 0271](0271-leftover-map-segment-distance.md).
 
 After `make seed`, closest and farthest leftover pairs sit above the
 member list. Click a pair to open that post with the leftover

docs/adr/0268-leftover-map-graphic-display.md

@@ -6,7 +6,9 @@
 **Amended by:** [ADR 0269](0269-leftover-map-axis-share-plot.md)
 (leftover-map axis share on the graphic display);
 [ADR 0270](0270-leftover-map-coordinate-ticks.md)
-(leftover-map coordinate ticks)
+(leftover-map coordinate ticks);
+[ADR 0271](0271-leftover-map-segment-distance.md)
+(leftover-map distance on pair segments)
 
 Amends [ADR 0049](0049-leftover-pair-report-ui.md) and
 [ADR 0267](0267-leftover-map-coordinates.md). Independent of leftover-map
@@ -80,7 +82,8 @@ member list with the leftover-map graphic display of persisted `ξ`
 and `ζ`; click a post marker or a pair button opens that post.
 Hidden posts stay hidden. Leftover-map axis share captions those
 leftover-map axes when finite (ADR 0269). Leftover-map axis ticks name
-persisted `ξ` / `ζ` coordinates (ADR 0270). When coordinates, reconstruction, and
+persisted `ξ` / `ζ` coordinates (ADR 0270). Pair segments name
+persisted leftover-map distance `d` (ADR 0271). When coordinates, reconstruction, and
 distance are all finite, `R̂ = ξ_{1:2} · ζ_{1:2}` and
 `d = ‖ξ_{1:2} − ζ_{1:2}‖` remain the same identities already
 persisted by ADR 0267.

docs/adr/0270-leftover-map-coordinate-ticks.md

@@ -12,6 +12,8 @@ leftover-map unexplained leftover share
 ([ADR 0233](0233-leftover-map-unexplained-share.md)), leftover-map
 reconstruction ([ADR 0201](0201-leftover-map-reconstruction.md)), and
 leftover-map axis share persistence ([ADR 0148](0148-leftover-map-axis-share.md)).
+Independent of leftover-map distance on pair segments
+([ADR 0271](0271-leftover-map-segment-distance.md)).
 
 ## Context
 
@@ -90,7 +92,8 @@ inner product, leftover-map cosine, leftover-map length, leftover-map
 reconstruction, leftover-map unexplained leftover, leftover-map cross
 share, leftover-map unexplained leftover share, leftover-map explained
 leftover share, leftover-map coordinate persistence, leftover-map
-graphic display, and leftover-map axis share on the graphic display.
+graphic display, leftover-map axis share on the graphic display, and
+leftover-map distance on pair segments.
 
 ## References
 

docs/adr/0271-leftover-map-segment-distance.md

@@ -0,0 +1,108 @@
+# ADR 0271 — Name leftover-map distance on graphic-display pair segments
+
+**Decision status:** Accepted
+**Date:** 2026-08-29
+
+Amends [ADR 0268](0268-leftover-map-graphic-display.md) and
+[ADR 0049](0049-leftover-pair-report-ui.md). Independent of leftover-map
+coordinate ticks ([ADR 0270](0270-leftover-map-coordinate-ticks.md)),
+leftover-map axis share on the graphic display
+([ADR 0269](0269-leftover-map-axis-share-plot.md)), leftover-map
+explained leftover share ([ADR 0266](0266-leftover-map-explained-share.md)),
+leftover-map unexplained leftover share
+([ADR 0233](0233-leftover-map-unexplained-share.md)), leftover-map
+reconstruction ([ADR 0201](0201-leftover-map-reconstruction.md)), and
+leftover-map axis share persistence ([ADR 0148](0148-leftover-map-axis-share.md)).
+
+## Context
+
+ADR 0267 already persists leftover-map distance
+`d = ‖ξ_{1:2} − ζ_{1:2}‖` on leftover pair rows next to coordinates
+`ξ_{1:2}` / `ζ_{1:2}`. ADR 0268 already draws the connecting segment
+between those positions. ADR 0270 already ticks leftover-map axes at
+the persisted coordinates. The segment still has no leftover-map
+distance label, so a buyer who reads `d 0.12` on the pair row cannot
+match that length to the graphic line. Hiding `d` on the segment lets
+leftover residual `R`, reconstruction `R̂`, or leftover-map location
+be read as leftover-map distance even after the coordinates and ticks
+are named.
+
+This increment names leftover-map graphic-display pair segments with
+persisted leftover-map distance. It does not add columns. It does not
+recompute `d` from plotted pixel length or from coordinates. It does
+not persist leftover-map inner product, cosine, or length. It does not
+land Post quality on the leftover criterion. Leftover-map distance
+stays two-axis Euclidean. Do not invent a leftover score. Do not
+invent a theta.
+
+The dashboard stack already used neighbouring leftover facts under
+other numbers. This protected increment uses **0271** so it does not
+collide with leftover-map coordinate ticks (0270), leftover-map axis
+share on the graphic display (0269), leftover-map graphic display
+(0268), leftover-map coordinates (0267 / migration 0245), leftover-map
+explained leftover share (0266 / migration 0244), leftover-map
+unexplained leftover share (0233 / migration 0233), leftover-map
+reconstruction (0201 / migration 0206), leftover-map cross share
+(0185), leftover residual disclosure, leftover observed `Y` /
+expected `E`, leftover-map rank, two-axis leftover-map distance
+persistence, leftover coverage, leftover-map axis share persistence
+(0148), leftover interaction-map persistence, occupational construct
+catalog search (0265), or the dashboard stacks.
+
+## Decision
+
+On the leftover-map graphic display, caption each closest or farthest
+pair segment with the same persisted leftover-map distance formatter
+as the pair-row `d` badge. A missing or non-finite `d` omits that
+segment caption and keeps the connecting line. Rank-0 origin cells
+still name `d 0.00` when that persisted distance is finite. Do not
+invent `d` from plotted coordinates or pixel length. Click a post
+marker to open that post. Criterion markers are not post buttons. The
+grouping comparison strip (ADR 0149) stays on its reduced leftover
+payload and does not gain these segment captions.
+
+Do not add SQL. Do not edit shipped migrations. Do not persist inner
+product, cosine, or length as separate columns. Do not invent a
+leftover score. Do not invent a theta.
+
+## Consequences
+
+After `make seed`, closest and farthest leftover pairs sit above the
+member list with the leftover-map graphic display of persisted `ξ`
+and `ζ`, leftover-map axes name persisted Gabriel inertia share when
+finite, leftover-map axis ticks name the same coordinates shown on
+the pair row, and pair segments name persisted leftover-map distance
+`d`; click a post marker or a pair button opens that post. Hidden
+posts stay hidden. Rank-0 unused axes still plot at the origin, still
+name zero leftover-map axis share with a `0` tick, and still name
+`d 0.00` when that distance is persisted. When coordinates,
+reconstruction, and distance are all finite, `R̂ = ξ_{1:2} · ζ_{1:2}`
+and `d = ‖ξ_{1:2} − ζ_{1:2}‖` remain the same identities already
+persisted by ADR 0267.
+
+## Related
+
+Independent of leftover interaction-map persistence, leftover-criterion
+evaluation landing, leftover residual disclosure, leftover observed
+`Y` / expected `E`, leftover-map complete-case coverage, leftover-map
+axis share persistence, leftover pairs on the grouping comparison
+strip, two-axis leftover-map distance persistence, leftover-map rank,
+leftover-map inner product, leftover-map cosine, leftover-map length,
+leftover-map reconstruction, leftover-map unexplained leftover,
+leftover-map cross share, leftover-map unexplained leftover share,
+leftover-map explained leftover share, leftover-map coordinate
+persistence, leftover-map graphic display, leftover-map axis share on
+the graphic display, and leftover-map coordinate ticks.
+
+## References
+
+Gabriel, K. R. (1971). The biplot graphic display of matrices with
+application to principal component analysis. *Biometrika, 58*(3),
+453–467. https://doi.org/10.1093/biomet/58.3.453
+
+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.
+https://doi.org/10.1007/s11336-021-09762-5
+(LSIRM interaction `−γ‖ξ_j − ζ_i‖` after main effects
+`α_j − β_i`; typically `p = 2` for the interaction map.)

docs/product-technical-gap-baseline.md

@@ -1,5 +1,28 @@
 # Product & Technical Gap Baseline
 
+> Exact-head loop overlay: 2026-08-29 13:20 KST. Protected `main` is
+> `fc13acaa20adca11968238e398d4aafcf62b6cee` (v2.23.0 leftover-map
+> explained leftover share, #775). Open ready PRs still lack independent
+> APPROVE. #782 leftover-map coordinates + graphic + axis share + ticks
+> (v2.24.0–v2.27.0 / ADR 0267–0270) is on
+> `2a203bf8b75b987ba899a0006a312d81259b9124` after #799 squash-merged
+> into the unprotected leftover branch. Auto-merge squash remains armed
+> on #782/#780/#774/#772/#771/#770. Independent APPROVE is still
+> required for protected main. Drafts remain dirty against `main`. #96
+> stays closed as a weaker duplicate of #91. GitHub writes through
+> `gh`/MCP succeed. Copilot review is not independent APPROVE. Do not
+> self-approve. Do not `gh pr merge` stacked leftover PRs onto an
+> unprotected leftover base.
+>
+> Next buyer increment on this cycle: leftover-map distance on
+> graphic-display pair segments (ADR 0271 / v2.28.0). Caption each
+> closest/farthest segment with persisted leftover-map distance `d` so
+> the pair-row badge matches the graphic line. UI-only; no new columns.
+> Missing/non-finite `d` omits that segment caption. Do not invent `d`
+> from plotted coordinates. Do not invent leftover scores. Stack onto
+> leftover branch `feat/leftover-map-coordinates-v2240`; leave the PR
+> open for independent review.
+
 > Exact-head loop overlay: 2026-08-29 13:15 KST. Protected `main` is
 > `fc13acaa20adca11968238e398d4aafcf62b6cee` (v2.23.0 leftover-map
 > explained leftover share, #775). Open ready PRs still lack independent