feat(ms-ai-architect): Spor D Steg C — skill-quality SessionStart-surfacing (TDD) [skip-docs]

summarizeSkillQuality(cache) (pure) in detection-schedule.mjs: one-liner
"Skill-kvalitet: N skills < 90 % (navn)"; null when all skills meet target,
when the cache is missing (gitignored → absent in a fresh clone), or when the
shape is malformed. Reads the CACHED skill-score-report.json (from Steg B) —
never scores live (buildReport reads ~400 ref-files). Wired into
session-start-context.mjs after the course-signals block (same
existsSync/try-catch pattern). 7 new tests (kb-update 316 → 323).

[skip-docs]: README is the public end-user doc; skill-quality scoring is
maintainer-only tooling (the cache is gitignored, so the signal never surfaces
for end-users). The right doc homes ARE updated: CLAUDE.md hook table + a
caveat note (this commit), and docs/skill-quality-scoring-plan.md §3 komponent 4.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -104,9 +104,17 @@ Se `references/architecture/recommended-mcp-servers.md` for detaljer.
 
 | Event | Script | Formål |
 |-------|--------|--------|
-| SessionStart | `session-start-context.mjs` | Viser aktive utredninger, KB-ferskhet, onboarding-status, skill- + kurs-signaler (Spor C) + AI Act-frister |
+| SessionStart | `session-start-context.mjs` | Viser aktive utredninger, KB-ferskhet, onboarding-status, skill- + kurs-signaler (Spor C), skill-kvalitetssignaler (Spor D — skills under 90 %, fra cachet score-rapport) + AI Act-frister |
 | Stop | `stop-assessment-reminder.mjs` | Påminnelse om ucommittede vurderinger, neste steg |
 
+> Skill-kvalitetssignalet (Spor D) leser den **cachede** rapporten
+> `scripts/kb-eval/data/skill-score-report.json` og scorer aldri live
+> (buildReport leser ~400 ref-filer — for dyrt i en SessionStart-hook).
+> Cachen er gitignored (derivert/regenererbar via `score-skill.mjs --write`),
+> så den er fraværende i en fersk klon: linja surfacer kun for en vedlikeholder
+> som har produsert cachen lokalt, aldri for en sluttbruker. Alle skills ≥90 %
+> ⇒ ingen linje.
+
 > Secrets scanning consolidated to llm-security plugin.
 
 ## Reference docs (read on demand)

hooks/scripts/session-start-context.mjs

@@ -11,6 +11,7 @@ import {
   shouldRunDetection,
   summarizeSkillLifecycle,
   summarizeCourses,
+  summarizeSkillQuality,
 } from '../../scripts/kb-update/lib/detection-schedule.mjs';
 import {
   resolveOrgDir,
@@ -203,6 +204,21 @@ if (existsSync(courseReportPath)) {
   }
 }
 
+// Skill-quality score signals (Spor D / Steg C) — read-only one-liner; never
+// spawns, never scores live. Reads the CACHED skill-score-report.json (written
+// by `score-skill.mjs --write`). The cache is gitignored => absent in a fresh
+// clone, so this surfaces only for a maintainer who has produced it locally;
+// summarizeSkillQuality tolerates the missing/malformed case → null.
+const scoreCachePath = join(pluginRoot, 'scripts', 'kb-eval', 'data', 'skill-score-report.json');
+if (existsSync(scoreCachePath)) {
+  try {
+    const qualitySummary = summarizeSkillQuality(JSON.parse(readFileSync(scoreCachePath, 'utf8')));
+    if (qualitySummary) parts.push(qualitySummary);
+  } catch {
+    // Ignore — advisory only
+  }
+}
+
 if (nearestDeadline) {
   parts.push(`EU AI Act: ${nearestDeadline.daysLeft} dager til ${nearestDeadline.label}. Kjør /architect:classify`);
 }

scripts/kb-update/lib/detection-schedule.mjs

@@ -256,3 +256,47 @@ export function summarizeCourses(report) {
   if (changed > 0) parts.push(`${changed} endrede`);
   return parts.length ? `Kurs-signaler: ${parts.join(' / ')} kurs i dekkede produkter` : null;
 }
+
+// Default skill-quality target (%). The score cache always carries its own
+// `target` (buildScoreCache); this literal is only a defensive fallback for an
+// older/partial cache. Mirrors TARGET in scripts/kb-eval/lib/skill-score.mjs —
+// kept local so this Claude-free kb-update module never imports the kb-eval lib.
+const SKILL_QUALITY_TARGET_DEFAULT = 90;
+
+/**
+ * Build a compact one-liner summarizing skill-quality scores (Spor D / Steg C)
+ * for the SessionStart hook. Pure; tolerant of partial/missing caches. Mirrors
+ * summarizeSkillLifecycle / summarizeCourses.
+ *
+ * Consumes the CACHED score report (scripts/kb-eval/data/skill-score-report.json,
+ * produced by `score-skill.mjs --write`) — it NEVER scores live: buildReport
+ * reads ~400 ref-files, far too expensive for a SessionStart hook. That cache is
+ * gitignored (derived/regenerable), so it is ABSENT in a fresh clone — this MUST
+ * tolerate a missing/malformed cache → null and never crash the hook. In
+ * practice the one-liner therefore surfaces only for a maintainer who has run
+ * `--write` locally, never for an end-user of a fresh checkout.
+ *
+ * Surfaces ONLY skills below target. Returns null when every skill meets target,
+ * when the cache is missing/non-object, or when it carries no usable skill data.
+ * @param {object|null} cache  parsed skill-score-report.json
+ *   ({target, scored:[{name, meetsTarget}], below:[name]})
+ * @returns {string|null}
+ */
+export function summarizeSkillQuality(cache) {
+  if (!cache || typeof cache !== 'object') return null;
+  const target = Number.isFinite(cache.target) ? cache.target : SKILL_QUALITY_TARGET_DEFAULT;
+  // Trust the precomputed `below` name-list; fall back to deriving it from
+  // `scored` (tolerant of an older/partial shape). Neither present => unusable.
+  let below;
+  if (Array.isArray(cache.below)) {
+    below = cache.below;
+  } else if (Array.isArray(cache.scored)) {
+    below = cache.scored.filter((s) => s && s.meetsTarget === false).map((s) => s.name);
+  } else {
+    return null;
+  }
+  below = below.filter(Boolean);
+  if (below.length === 0) return null;
+  const noun = below.length === 1 ? 'skill' : 'skills';
+  return `Skill-kvalitet: ${below.length} ${noun} < ${target} % (${below.join(', ')})`;
+}

tests/kb-update/test-detection-schedule.test.mjs

@@ -26,6 +26,7 @@ import {
   selectDetectionSteps,
   summarizeSkillLifecycle,
   summarizeCourses,
+  summarizeSkillQuality,
   daysSinceLastPoll,
 } from '../../scripts/kb-update/lib/detection-schedule.mjs';
 import { writeScheduleConfig } from '../../scripts/kb-update/write-schedule-config.mjs';
@@ -469,6 +470,92 @@ test('summarizeCourses — tolerates a missing/partial report shape', () => {
   assert.equal(summarizeCourses({ status: 'ok' }), null); // no counts
 });
 
+// ===========================================================================
+// (C3) summarizeSkillQuality — skill-quality one-liner at session start (Spor D / Steg C)
+// ===========================================================================
+// Reads the CACHED skill-score-report.json (produced by `score-skill.mjs
+// --write`), it NEVER scores live — buildReport reads ~400 ref-files, far too
+// expensive for a SessionStart hook. The cache is gitignored => ABSENT in a
+// fresh clone, so this MUST tolerate a missing/malformed cache → null and never
+// crash the hook. Mirrors summarizeCourses / summarizeSkillLifecycle: a pure
+// one-liner, null when there is nothing worth surfacing (all skills ≥ target).
+
+const SCORE_CACHE_ALL_PASS = {
+  generatedAt: '2026-06-23',
+  target: 90,
+  scored: [
+    { name: 'ms-ai-advisor', score: 91, meetsTarget: true },
+    { name: 'ms-ai-security', score: 96, meetsTarget: true },
+  ],
+  below: [],
+};
+
+const SCORE_CACHE_TWO_BELOW = {
+  generatedAt: '2026-06-23',
+  target: 90,
+  scored: [
+    { name: 'ms-ai-advisor', score: 88, meetsTarget: false },
+    { name: 'ms-ai-engineering', score: 72, meetsTarget: false },
+    { name: 'ms-ai-security', score: 96, meetsTarget: true },
+  ],
+  below: ['ms-ai-advisor', 'ms-ai-engineering'],
+};
+
+test('summarizeSkillQuality — surfaces the count + names of skills below target', () => {
+  const s = summarizeSkillQuality(SCORE_CACHE_TWO_BELOW);
+  assert.match(s, /Skill-kvalitet:/);
+  assert.match(s, /2 skills < 90 %/, 'canonical one-liner form (spec §3 komponent 4)');
+  assert.match(s, /ms-ai-advisor/);
+  assert.match(s, /ms-ai-engineering/);
+});
+
+test('summarizeSkillQuality — singular noun for exactly one skill below target', () => {
+  const s = summarizeSkillQuality({
+    target: 90,
+    below: ['ms-ai-advisor'],
+    scored: [{ name: 'ms-ai-advisor', meetsTarget: false }],
+  });
+  assert.match(s, /1 skill < 90 %/);
+  assert.doesNotMatch(s, /1 skills/, 'no plural "skills" for a single skill');
+});
+
+test('summarizeSkillQuality — all skills meet target returns null (nothing to surface)', () => {
+  assert.equal(summarizeSkillQuality(SCORE_CACHE_ALL_PASS), null);
+});
+
+test('summarizeSkillQuality — missing cache (fresh clone, gitignored) returns null', () => {
+  assert.equal(summarizeSkillQuality(null), null);
+  assert.equal(summarizeSkillQuality(undefined), null);
+});
+
+test('summarizeSkillQuality — malformed cache returns null (never crashes the hook)', () => {
+  assert.equal(summarizeSkillQuality({}), null, 'no below[] and no scored[] => unusable');
+  assert.equal(summarizeSkillQuality('nonsense'), null, 'non-object');
+  assert.equal(summarizeSkillQuality({ target: 90 }), null, 'target only, no skill data');
+});
+
+test('summarizeSkillQuality — uses the cache target in the message (not a hardcoded 90)', () => {
+  const s = summarizeSkillQuality({
+    target: 85,
+    below: ['ms-ai-advisor'],
+    scored: [{ name: 'ms-ai-advisor', meetsTarget: false }],
+  });
+  assert.match(s, /< 85 %/);
+});
+
+test('summarizeSkillQuality — derives below from scored when below[] is absent (shape tolerance)', () => {
+  const s = summarizeSkillQuality({
+    target: 90,
+    scored: [
+      { name: 'ms-ai-advisor', meetsTarget: false },
+      { name: 'ms-ai-security', meetsTarget: true },
+    ],
+  });
+  assert.match(s, /1 skill < 90 %/);
+  assert.match(s, /ms-ai-advisor/);
+  assert.doesNotMatch(s, /ms-ai-security/, 'only below-target skills are named');
+});
+
 // ===========================================================================
 // (D) STRUCTURAL ToS GUARANTEE — detection is Claude-free
 // ===========================================================================