chore(tag-vocab): #3 closure — gates verified + roadmap mark complete

- typecheck 0 / 단위 384 / e2e 1
- v0.2.3 6/7 (#3 태그 vocab 머지)
- 다음: #6 리마인드 spike (마지막 항목)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/superpowers/specs/2026-05-01-v023-feedback-roadmap-design.md

@@ -154,7 +154,7 @@ v0.2.2 ────────[ dogfood 동결, 병렬 진행 ]─────
 
 **Out:** per-note retry 버튼 (NoteCard), failed reason 별 차등 정책, retry progress UI, retry rate-limit
 
-### #3 태그 vocab (6번)
+### #3 태그 vocab (6번) ✓ 완료
 
 **In:**
 - `NoteRepository.getTopUsedTags(N=20)`: