[CLAUDE] Docs+Skill: chốt session 8 ending — patch count drift + skill refresh

Session 8 ending workflow theo template (kết thúc lúc ~13:00).

Patch drift count post Migration 16:
- docs/architecture.md §1: "(dbo schema, 19 bảng)" → 55 bảng
  (drift cũ session 6 chưa fix, giờ fix luôn)
- docs/database/schema-diagram.md §8 Migration history: thêm row 16
  AddTwoStageDeptApprovalAndSmartReject + Tổng 52 → 55 bảng
- .claude/skills/ef-core-migration/SKILL.md: 15→16 migration history,
  52→55 tables, description + code pointers + related links
- .claude/skills/README.md: ef-core-migration row "13 migration" → 16,
  gotchas count "32 bẫy" → 41 (drift cũ chưa fix)

Memory entry mới (cross-session pattern):
- feedback_per_chunk_commit.md: rule per-chunk commit cho big-feature
  (>500 LOC, multi-layer). Bài học S8 — 5 commit A-B-C-D-E thay vì
  1 monolithic. MEMORY.md index +1 entry (6 total).

Skip (intentional, theo §6.5 KHÔNG cố sửa):
- docs/gotchas.md: KHÔNG có gotcha mới đáng note (S8 dùng pattern
  đã proven, không có bug pitfall mới)
- docs/database/database-guide.md: KHÔNG có migration table chi tiết,
  chỉ conventions. Skip.
- contract-workflow + permission-matrix skills: KHÔNG touch (PE module
  only, contract policy chưa đổi, permission không liên quan bypass-review)

Verify:
- 77 unit test vẫn pass (54 Domain + 23 Infra)
- Build pass

Total session 8 cumulative: 6 commit (5 code A-B-C-D-E1 + 1 docs ending).

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

docs/database/schema-diagram.md

@@ -484,8 +484,9 @@ COMMIT;
 | **13** | **`AddPurchaseEvaluationCodeSequences`** | **PurchaseEvaluationCodeSequences (Prefix PK, atomic seq mirror ContractCodeSequences). Format MaPhieu PE/{YYYY}/{A\|B}/{Seq:D3}** |
 | **14** | **`AddBudgets`** | **4 bảng module Ngân sách: Budgets + BudgetDetails + BudgetApprovals + BudgetChangelogs. + nullable FK index Contract.BudgetId & PurchaseEvaluation.BudgetId** |
 | **15** | **`AddPurchaseEvaluationDepartmentOpinions`** | **1 bảng `PurchaseEvaluationDepartmentOpinions` (UNIQUE PEId+Kind, max 1 row mỗi loại phòng ban per phiếu — UPDATE in-place, audit qua Changelog)** |
+| **16** | **`AddTwoStageDeptApprovalAndSmartReject`** | **3 bảng `Contract/PurchaseEvaluation/Budget DepartmentApprovals` (UNIQUE TargetId+Phase+Dept+Stage cho 2-stage NV/TPB approval per phòng × phase) + 4 ALTER (`Users.CanBypassReview` bit + 3 `RejectedFromPhase` int cho smart reject quay về Drafter + jump-back phase đã reject)** |
 
-Tổng: **52 bảng** (+ `__EFMigrationsHistory` hệ thống).
+Tổng: **55 bảng** (+ `__EFMigrationsHistory` hệ thống).
 
 ## 8bis. Bảng mới sau Migration 9-11