Code-quality reviewer flagged stylistic divergence from auth's pattern:
- All 3 blog use cases now have // ── Input ──... / ── Output ──... /
── Use case ──... section dividers (consistent with auth Task 3 + plan
template §4.1).
- Removed inline comment in get-articles controller's presenter that
appeared in only 1 of 3 controllers; identity presenters are
self-explanatory.