chore: update vendored skills and record provenance

humanizer 2.2.0 -> 2.9.1 (blader/humanizer, MIT): adds a Voice
Calibration section and a passive-voice pattern, reworks negative
parallelisms and em dashes. Version moved to metadata.version upstream.

impeccable 3.6.0 -> 4.0.4 (pbakaus/impeccable, Apache-2.0): the repo
tags the skill and the npm CLI separately, so 3.6.0 was a real release
and npm's 3.5.0 was never the comparison. Adds native-platform reference
briefs.

Each now carries an UPSTREAM file; bin/check-vendored.sh reports drift.

skills/impeccable/scripts/detector/detect-antipatterns.mjs

@@ -23,6 +23,13 @@ export {
   checkHtmlPatterns,
 } from './rules/checks.mjs';
 export { createDetectorProfile, summarizeDetectorProfile } from './profile/profiler.mjs';
+export {
+  parseFrontmatter as parseDesignFrontmatter,
+  normalizeDesignSystem,
+  loadDesignSystemForCwd,
+  checkSourceDesignSystem,
+  collectStaticDesignSystemFindings,
+} from './design-system.mjs';
 export { detectHtml } from './engines/static-html/detect-html.mjs';
 export { detectUrl, createBrowserDetector } from './engines/browser/detect-url.mjs';
 export { detectText, extractStyleBlocks, extractCSSinJS } from './engines/regex/detect-text.mjs';