[CLAUDE] Docs+Skill: chốt Session 14 wrap-up — PE 3-button workflow + Task 2 defer

Session 14 (2026-05-07) docs/skill update:

STATUS.md:
- Last updated + Phase summary count (95→96 test, 20 mig, 57 bảng, 41 gotcha)
- Recently Done row Session 14 chi tiết (3-button + Task 2 in-progress + DesignTime/Runtime DB gotcha)

HANDOFF.md:
- TL;DR Session 14 prepend với 1 commit + Task 2 defer
- 5 cảnh báo Session 15+: TraLai phase orphan / Task 2 sample seed / DesignTime
  vs Runtime DB / Budget N-stage defer / schema-diagram §17-19 defer

migration-todos.md: Phase 9 + Session 14 block 4 sub-task done + 2 defer task

Session log NEW `2026-05-07-2500-3-button-workflow.md`:
- Bối cảnh + spec 3-button (Duyệt/Trả lại/Từ chối) + implementation chi tiết
  (Domain policy expand + Service tách reject + FE button + dialog warning)
- Tests update (95→96 với +1 NEW Reject_To_TuChoi_Locks_Permanently)
- Task 2 in-progress: DesignTime vs Runtime DB gotcha + API exit 255 sớm
- Plan organization sau S14

Skill ef-core-migration:
- description + heading: 17→20 migration
- Bảng migration history thêm Mig 18-19 (PE) + Mig 20 (Contract)
- Section MỚI "N-stage workflow pattern (Mig 18-20)" — architecture decision
  với filtered unique trick + per-module migration packaging guideline
- Phase 8 update: 83→96 test breakdown

Skill contract-workflow:
- Section MỚI "Phase 9+ done (Mig 18-20 — Session 12/13/14)":
  * N-stage workflow PE + Contract (entity + filtered unique split + service
    refactor + tests + FE Designer + UsersPage cấp + API)
  * PE 3-button approval (Duyệt/Trả lại/Từ chối) Session 14
  * Defer: Budget N-stage / Phase TraLai=98 orphan

CLAUDE.md root: 16→20 migration + 55→57 bảng + 83→96 test
docs/rules.md §7: Phase 9 active 83→96 test

Verify: dotnet test 96 pass + npm build (skip — pure docs/skill update).

🎉 Session 14 wrap-up complete. Pushed 1 task (3-button) + Task 2 defer.
Cumulative since session start (13h17): 13 commit (1 button removal +
6 PE N-stage Chunk A-F + 5 Contract N-stage Chunk A,B,C,D,F + 1 3-button).

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

.claude/skills/ef-core-migration/SKILL.md

@@ -1,6 +1,6 @@
 ---
 name: ef-core-migration
-description: Tạo/sửa/revert EF Core 10 migration cho SOLUTION_ERP. Dùng khi thêm entity mới, thay đổi schema, rollback migration, debug DesignTimeDbContextFactory fail. Đã có 16 migration sẵn (Init → AddTwoStageDeptApprovalAndSmartReject). Snapshot + Designer + Migration 3-file rule bắt buộc commit đủ.
+description: Tạo/sửa/revert EF Core 10 migration cho SOLUTION_ERP. Dùng khi thêm entity mới, thay đổi schema, rollback migration, debug DesignTimeDbContextFactory fail. Đã có 20 migration sẵn (Init → AddContractWorkflowInnerStepsAndAlterDeptApprovalUnique). Snapshot + Designer + Migration 3-file rule bắt buộc commit đủ.
 when-to-use:
   - "thêm migration"
   - "EF Core migration"
@@ -16,7 +16,7 @@ when-to-use:
 
 > **Context:** .NET 10 + EF Core 10 + SQL Server. DbContext: `ApplicationDbContext` ở `Infrastructure/Persistence/`. Startup: `SolutionErp.Api`.
 
-## Migration history (17 migration hiện có)
+## Migration history (20 migration hiện có)
 
 | # | Name | Tables added / changed |
 |---|---|---|
@@ -37,8 +37,29 @@ when-to-use:
 | **15** | **`AddPurchaseEvaluationDepartmentOpinions`** | **1 bảng `PurchaseEvaluationDepartmentOpinions` (UNIQUE PEId+Kind, max 1 row mỗi PeDepartmentKind per phiếu — Phê duyệt/Ccm/MuaHang/SmPm)** |
 | **16** | **`AddTwoStageDeptApprovalAndSmartReject`** | **3 bảng `Contract/PurchaseEvaluation/Budget DepartmentApprovals` (UNIQUE TargetId+Phase+Dept+Stage cho 2-stage NV.Review → TPB.Confirm per phòng × phase) + 4 ALTER (`Users.CanBypassReview` bit cho NV bypass + 3 `RejectedFromPhase` int cho smart reject jump-back). Phase 9 — đóng bug "NV duyệt được hết phase" anh Kiệt (FDC) báo. Logic 2-stage trong PurchaseEvaluationWorkflowService chỉ áp PE; HĐ + Budget defer.** |
 | **17** | **`AddManualBudgetFieldsToPeAndContract`** | **4 ALTER (PE + HĐ × `BudgetManualName` nvarchar(200) + `BudgetManualAmount` decimal(18,2)) — manual budget fallback khi user không link Budget entity approved. KHÔNG XOR với BudgetId, cả 2 cùng null OK. Carry-forward `pe.BudgetManualName/Amount → contract` ở `CreateContractFromEvaluation`. Phase 9 — Session 11 (2026-05-07).** |
+| **18** | **`AddPeWorkflowInnerStepsAndPositionLevel`** | **N-stage workflow PE — 1 CREATE TABLE `PurchaseEvaluationWorkflowStepInnerSteps` (Order, DepartmentId, PositionLevel, Name, SlaDays, IsRequired) + 2 ALTER (`Users.PositionLevel int?` 1=NV/2=PP/3=TP + `PEDeptApproval.InnerStepId Guid?`) + 3 IX + FK Cascade Step / Restrict Dept+InnerStep. Phase 9+ — Session 12 (2026-05-07).** |
+| **19** | **`AlterPeDeptApprovalsUniqueFilteredForInnerSteps`** | **Filtered unique split: drop UNIQUE cũ Mig 16 → 2 filtered: legacy `WHERE InnerStepId IS NULL` (Stage Review/Confirm) + N-stage `WHERE InnerStepId IS NOT NULL` (per inner step). Tránh conflict 2 inner step cùng dept Stage=Confirm. Session 12.** |
+| **20** | **`AddContractWorkflowInnerStepsAndAlterDeptApprovalUnique`** | **N-stage workflow Contract mirror PE Mig 18+19 — GỘP 1 migration: CREATE TABLE `WorkflowStepInnerSteps` + ALTER `ContractDeptApproval.InnerStepId` + DropIndex old + Recreate filtered legacy/N-stage + 3 IX + FK. Session 13 (2026-05-07).** |
 
-Total: **55 bảng** dbo + `__EFMigrationsHistory` (Mig 17 không thêm bảng, chỉ +4 cột). Xem `docs/database/schema-diagram.md` ERD đầy đủ.
+Total: **57 bảng** dbo + `__EFMigrationsHistory` (Mig 17 alter cột; Mig 18 + Mig 20 thêm 1 bảng/mỗi; Mig 19 chỉ alter index). Xem `docs/database/schema-diagram.md` ERD đầy đủ.
+
+## N-stage workflow pattern (Mig 18-20 — Session 12-13)
+
+Architecture decision đáng ghi cho session sau:
+
+**Pattern:** Mỗi WorkflowStep cha (= 1 phase) cấu hình động chuỗi InnerSteps con theo Department × PositionLevel với Order sequential. Approver cần khớp DeptId + PositionLevel + Order tiếp theo chưa duyệt. CanBypassReview cho user level cao hơn skip cấp dưới cùng dept.
+
+**Per-module migration** (PE first, mirror sang Contract sau):
+- PE: 2 migration tách (Mig 18 schema + Mig 19 alter index) — vì index issue phát hiện sau khi schema đã commit
+- Contract: 1 migration GỘP (Mig 20) — gộp CREATE TABLE + ALTER + DropIndex + Recreate filtered. Cleaner cho mirror.
+
+**Filtered unique trick:** legacy 2-stage rows (Mig 16, Stage=Review/Confirm) + N-stage rows (per InnerStep) cùng table `*DepartmentApprovals` → cần unique split:
+- `UX_*_Phase_Dept_Stage WHERE InnerStepId IS NULL` (legacy, prevent duplicate Review/Confirm cùng phase × dept)
+- `UX_*_Phase_InnerStep WHERE InnerStepId IS NOT NULL` (N-stage, prevent duplicate per inner step)
+
+**Backward compat 100%:** workflow no InnerSteps configured → service fallback legacy 2-stage logic Mig 16. Data legacy InnerStepId=null vẫn enforce unique cũ qua filtered index.
+
+**Budget defer:** Budget chưa có versioned WorkflowDefinition entity (hardcoded `BudgetPolicy.Default`). Để mirror N-stage Budget cần migration `AddBudgetVersionedWorkflow` trước (4 bảng + ALTER `Budget.WorkflowDefinitionId?`). Defer cho user quyết riêng.
 
 **Phase 7 pending:**
 - `AddPePaymentTermFields` — tách `PurchaseEvaluations.PaymentTerms` JSON thành 6 column riêng (Session 11+++++ đã thay UI Workspace `<Textarea>` JSON → `<Select>` 8 preset, BE schema vẫn nvarchar(max). Migration tách field defer cho khi BE cần aggregate/filter từng terms riêng)
@@ -50,7 +71,7 @@ Total: **55 bảng** dbo + `__EFMigrationsHistory` (Mig 17 không thêm bảng,
 
 **Phase 8 update (2026-04-29 Session 5):**
 - Migration 15 `AddPurchaseEvaluationDepartmentOpinions` — 1 bảng riêng (UNIQUE PEId+Kind), max 4 row mỗi phiếu cho 4 phòng ban (Phê duyệt/Ccm/MuaHang/SmPm). UPDATE in-place khi user đổi ý, audit qua Changelog.
-- Tests Phase 1-2-3mini-2stage live: `tests/SolutionErp.Domain.Tests/` (54 test policy state machine) + `tests/SolutionErp.Infrastructure.Tests/` (17 test code generator + 6 test PE WF versioning + 6 test PE 2-stage approval Session 9). **Total 83 test pass / ~3s**. CI fail → no deploy.
+- Tests Phase 1-2-3mini-2stage-Nstage live: `tests/SolutionErp.Domain.Tests/` (54 test policy state machine) + `tests/SolutionErp.Infrastructure.Tests/` (17 test code generator + 6 test PE WF versioning + 6 test PE 2-stage Session 9 + 6 PE N-stage Session 12 + 6 Contract N-stage Session 13 + 1 PE Reject Từ chối Session 14). **Total 96 test pass / ~3s**. CI fail → no deploy.
 - CI optimize 3 fix (29/04):
   - Manual checkout bypass github.com (gotcha #39) — fix TCP timeout 21s
   - Path filter docs-only skip (gotcha #41) — commit MD-only KHÔNG trigger CI