[CLAUDE] Docs+Skill: audit định kỳ 2026-05 — 6 file patch + 1 log page

Combined audit (skill staleness + doc drift) theo §6.4 + §9.4. Cron 2026-05-01 trễ 4 ngày (cron empty), chạy manual 2026-05-04 sau Session 9 close Chunk E-bis.

Drift patched (Phase 1 — count cross-check):
- docs/CLAUDE.md:70    52 bảng → 55 bảng (+§14 DepartmentApprovals Mig 16)
- docs/rules.md:368    Phase 8 active — 77 test → Phase 9 — 83 test
- docs/architecture.md:329, 365   77 test → 83 test (2 chỗ)
- .claude/skills/ef-core-migration/SKILL.md:52    77 test → 83 test + ghi 6 PE 2-stage S9
- .claude/skills/dependency-audit-erp/SKILL.md:153    26+ bẫy → 41 bẫy

Skill content patch (Phase 2 — staleness):
- contract-workflow: thêm "Phase 9 cross-ref (Mig 16)" block + section "Phase 9 done" (2-stage dept approval + smart reject + lock edit + CanBypassReview)
  → KHÔNG tạo skill 2-stage riêng (§9.5 anti-pattern "viết skill chỉ để có thêm")

KEEP per §6.5 (không cắt narrative):
- docs/rules.md:328 "52 bảng" example minh họa rule §6.5
- docs/changelog/migration-todos.md:152, 196 historical session record
- 9 session log mention 77/52 — snapshot lịch sử

Total patches: 6 file ~+30 / ~12 lines, KHÔNG rewrite, đáp ứng 3 câu validation §6.5.

Audit log: docs/changelog/skill-audit-2026-05.md (1 page max per cadence).

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

docs/architecture.md

@@ -326,7 +326,7 @@ Test pyramid bottom-heavy, **không E2E** (brittle, maintenance cao cho solo dev
 ├──────────────────────────────────┤  ✅ Done Phase 1 — 54 test
 │  Domain Policy (pure functions)  │     State machine + role transition + Registry mapping
 └──────────────────────────────────┘
-                                Total: 77 test pass / ~3s
+                                Total: 83 test pass / ~3s
 ```
 
 **Stack:**
@@ -362,7 +362,7 @@ Test pyramid bottom-heavy, **không E2E** (brittle, maintenance cao cho solo dev
 - CQRS handler có guard → 1 test mỗi guard branch
 - Bug found in production → 1 regression test added before merge
 
-Detail run: `dotnet test SolutionErp.slnx` chạy cả **77 test ~3s**.
+Detail run: `dotnet test SolutionErp.slnx` chạy cả **83 test ~3s**.
 
 ### CI/CD optimization (29/04)