Spec-reviewer PASS pointed two factual nits:
- MitrePage helper text still referenced the old 3-column drill-down ("Pick
a tactic on the left, then a technique..."). Reworded for the flat matrix
with the ▸ glyph + hover-for-id idiom.
- testing-m4.md + CHANGELOG were stale at 51/12; the actual counts are 53/14
after the GET /mitre/matrix tests landed. Reconciled.
No code-path change, no e2e fallout — DoD remains 53 pytest + 34 Playwright.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>