test: rebase parity baseline to v1.64.0.0; fix capture-vs-check drift

The parity ratchet had quietly failed for 7 skills — v1.58-v1.64 growth
landed past the v1.57.7.0 anchors and nothing caught it because this
test had no CI lane (verified pre-existing: SKILL.md content is
byte-identical to origin/main). Same rebase protocol as
v1.53->v1.57.7.0; old baseline retained for the audit trail.

Root-caused a second latent bug while rebasing: captureBaseline recorded
SKELETON-ONLY bytes while the checker compares UNION bytes (skeleton +
carved sections/*.md), so a fresh capture read carved skills at ~2x
ratio (ship: 82KB captured vs 183KB checked). captureBaseline now takes
sectionedSkills and records unions for carved skills — capture and check
measure the same thing, so the NEXT rebase can't hit this. Four
CARVE_GUARDS skeleton caps re-ratcheted to current +headroom
(plan-ceo 92K, plan-eng 70K, office-hours 100K, design-consultation
70K), annotated inline.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

test/helpers/capture-parity-baseline.ts

@@ -46,6 +46,14 @@ export interface ParityBaseline {
 export interface CaptureOptions {
   repoRoot: string;
   tag?: string;
+  /**
+   * Skills whose baseline bytes must be the UNION of skeleton + sections/*.md
+   * (mirroring parity-harness readSkillForParity, which is what the checker
+   * compares against). Omitting a carved skill here records skeleton-only
+   * bytes and the ratio check then reads ~2x on the next parity run — the
+   * exact capture-vs-check drift that broke the v1.64 rebase.
+   */
+  sectionedSkills?: string[];
 }
 
 /** Extract the frontmatter description from a SKILL.md file. Empty string if none. */
@@ -134,7 +142,7 @@ function getGitInfo(repoRoot: string): { commit: string; branch: string } {
 }
 
 export function captureBaseline(opts: CaptureOptions): ParityBaseline {
-  const { repoRoot, tag } = opts;
+  const { repoRoot, tag, sectionedSkills } = opts;
   const skillDirs = discoverSkillDirs(repoRoot);
   const evalCoverage = discoverEvalCoverage(repoRoot, skillDirs);
   const skills: Record<string, SkillBaselineEntry> = {};
@@ -144,7 +152,18 @@ export function captureBaseline(opts: CaptureOptions): ParityBaseline {
     const skillMdPath = path.join(repoRoot, dir, 'SKILL.md');
     const tmplPath = path.join(repoRoot, dir, 'SKILL.md.tmpl');
     const content = fs.readFileSync(skillMdPath, 'utf-8');
-    const bytes = Buffer.byteLength(content, 'utf-8');
+    let bytes = Buffer.byteLength(content, 'utf-8');
+    // Union in the carved sections for sectioned skills — semantic twin of
+    // parity-harness readSkillForParity (which the checker uses). Kept inline
+    // because parity-harness imports this module as a value (cycle).
+    if (sectionedSkills?.includes(dir)) {
+      const sectionsDir = path.join(repoRoot, dir, 'sections');
+      if (fs.existsSync(sectionsDir)) {
+        for (const f of fs.readdirSync(sectionsDir).filter(f => f.endsWith('.md')).sort()) {
+          bytes += Buffer.byteLength(fs.readFileSync(path.join(sectionsDir, f), 'utf-8'), 'utf-8');
+        }
+      }
+    }
     const lines = content.split('\n').length;
     const description = extractDescription(content);
     const descriptionLen = Buffer.byteLength(description, 'utf-8');

test/helpers/carve-guards.ts

@@ -144,7 +144,9 @@ export const CARVE_GUARDS: Record<string, CarveGuard> = {
     },
     behavioral: 'external',
     externalTest: 'test/skill-e2e-plan-ceo-review-section-loading.test.ts',
-    maxSkeletonBytes: 90_000,
+  // Re-ratcheted 2026-08 (v1.64 baseline rebase): v1.58-v1.64 growth landed
+  // while no CI lane ran the parity check; free-tests lane now enforces it.
+    maxSkeletonBytes: 92_000,
     minUnionBytes: 80_000,
     mustContain: ['SCOPE EXPANSION', 'SELECTIVE EXPANSION', 'HOLD SCOPE', 'SCOPE REDUCTION'],
     // Default-on Codex outside-voice (codexPreflight block + CODEX_MODE branch
@@ -165,7 +167,9 @@ export const CARVE_GUARDS: Record<string, CarveGuard> = {
     behavioral: 'plan',
     // v1.2.0 activation lift (shared first-run-guidance preamble) + #2077 ask-first scope gate.
     // +~1 KB: plan-mode auto-select-B scope-gate exceptions (2026-08).
-    maxSkeletonBytes: 68_000,
+  // Re-ratcheted 2026-08 (v1.64 baseline rebase): v1.58-v1.64 growth landed
+  // while no CI lane ran the parity check; free-tests lane now enforces it.
+    maxSkeletonBytes: 70_000,
     minUnionBytes: 70_000,
     mustContain: ['Architecture', 'Code Quality', 'Test', 'Performance'],
     // Cross-cutting preamble growth (v1.57.2.0 AUQ-failure prose fallback + the
@@ -240,7 +244,9 @@ export const CARVE_GUARDS: Record<string, CarveGuard> = {
     behavioral: 'prompt',
     // v1.2.0 activation lift: first-run-guidance section in the shared preamble,
     // plus the P1 office-hours closing handoff (AUQ that launches the next skill).
-    maxSkeletonBytes: 98_000,
+  // Re-ratcheted 2026-08 (v1.64 baseline rebase): v1.58-v1.64 growth landed
+  // while no CI lane ran the parity check; free-tests lane now enforces it.
+    maxSkeletonBytes: 100_000,
     minUnionBytes: 70_000,
     mustContain: ['design doc', 'problem statement'],
     maxSizeRatio: 1.07,
@@ -289,7 +295,9 @@ export const CARVE_GUARDS: Record<string, CarveGuard> = {
     // +Conductor AUQ-default-prose rule + one-way/continuation safety in the
     // always-loaded AskUserQuestion Format section.
     // v1.2.0 activation lift: first-run-guidance section in the shared preamble.
-    maxSkeletonBytes: 69_000,
+  // Re-ratcheted 2026-08 (v1.64 baseline rebase): v1.58-v1.64 growth landed
+  // while no CI lane ran the parity check; free-tests lane now enforces it.
+    maxSkeletonBytes: 70_000,
     minUnionBytes: 72_000,
     mustContain: ['Typography', 'Color', 'Aesthetic Direction'],
     // Cross-cutting preamble growth (v1.57.2.0 AUQ-failure prose fallback ~2KB +