[CLAUDE] Docs+Skill: chốt Session 16 wrap-up — drastic refactor flat workflow (Chunk D)

Session 16 (2026-05-08) docs/skill/memory wrap-up:

STATUS.md:
- Last updated Session 16 (2 commit Chunk A+B)
- Phase summary count (20→21 mig, 96→77 test, 57→55 bảng)
- Recently Done row Session 16 chi tiết (drastic refactor hoàn tất)
- Phase enum simplified semantic post-Mig 21

HANDOFF.md:
- TL;DR Session 16 prepend với 2 chunk + Chunk C SKIP rationale
- Per-chunk implementation chi tiết (Domain + Mig 21 + Service + Tests
  + FE Designer)
- 8 cảnh báo Session 17+: UAT live test / old data migration / Sample
  seed / Budget N-stage / schema-diagram / skill refresh / tests flat /
  Hard blockers Ops

migration-todos.md: Phase 9 + Session 16 block 2 chunk done + 7 defer task

Session log NEW `2026-05-08-0500-drastic-refactor-flat-workflow.md`:
- Bối cảnh resume từ S15 defer
- Spec implementation (Phase enum, state machine, schema Mig 21)
- Per-chunk Chunk A + Chunk B detail
- Chunk C skip rationale
- Memory `feedback_drastic_refactor_scope` validation:
  scope estimate 30% accurate (3h actual vs 10h conservative)
- Plan organization sau S16

Skill ef-core-migration:
- description + heading: 20→21 migration
- + Mig 21 row "RefactorWorkflowToFlatModel" với detail (4 ALTER + 2
  ALTER + DROP TABLE × 2 + DROP COLUMN × 2 + restore simple unique × 2)
- Total 57→55 bảng (-2 InnerStep tables)
- Tests: 96→77 (drop 19 legacy)

CLAUDE.md root:
- Migration count 20→21
- DB tables 57→55
- Workflow flat description thay N-stage description

docs/rules.md §7: 96→77 test (Mig 21 simplified)

Memory `project_solution_erp.md`:
- Add "Tổng sau session 16" block với drastic refactor details

🎉 Session 16 wrap-up. Cumulative since session start (S15 wrap-up
`38d10b7`): 4 commit (S15 wrap-up was final S15) + 3 commit Session 16
(A `dbb0089` + B `88a5be1` + D current).

Defer Session 17+ priority:
1. UAT live test workflow flat (3 phòng × N cấp realistic)
2. Old PE/HĐ legacy phase data migration
3. Sample data seed (Task 2 carry-over)
4. Hard blockers Ops

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

docs/HANDOFF.md

@@ -1,6 +1,107 @@
 # HANDOFF — Brief 5 phút cho session tiếp theo
 
-**Last updated:** 2026-05-07 (Session 15 — **Tooltip diagnose "Lưu & Gửi Duyệt" silent disabled (commit `835cc7f`). Plan drastic refactor flat workflow user chốt → attempt 12 file edits Domain/Configurations, realize scope ~8-10h vượt session, REVERT clean. State 96 test pass, 20 mig.**)
+**Last updated:** 2026-05-08 (Session 16 — **🎯 DRASTIC REFACTOR DONE: flat workflow Phòng × Cấp + Mig 21 + Service rewrite + FE Designer rewrite. 2 commit Chunk A+B. 96 → 77 test pass (drop 19 legacy). Backward compat: legacy phase 2-9+98 enum giữ cho data cũ.**)
+
+## TL;DR Session 16 (08/05 — Drastic refactor flat workflow EXECUTE)
+
+Resume từ Session 15 defer plan. Per memory `feedback_drastic_refactor_scope.md`: dedicated session, fresh context, conservative buffer.
+
+**Spec:** Workflow flat list (Phòng × Cấp × Approvers). Mỗi step = 1 (Phòng × Cấp). Service iterate steps OrderBy Order, advance pointer. Phase enum simplify ChoDuyet=10. Pin WorkflowDefinitionId.
+
+**2 chunk per-commit (5-6 chunk plan rút gọn vì BE tightly coupled):**
+
+### Chunk A (`dbb0089`) — All BE: Domain + Mig 21 + Service + Tests
+
+**Domain entities:**
+- Phase enum (PE + Contract): + ChoDuyet=10 generic intermediate. Legacy 2-6 + 98 deprecated (giữ enum cho data cũ).
+- WorkflowStep + DepartmentId Guid? FK Restrict + PositionLevel int?
+- PurchaseEvaluation/Contract + CurrentWorkflowStepIndex int? + RejectedAtStepIndex int?
+- DROP class WorkflowStepInnerStep + nav (PE + Contract)
+- DROP *DepartmentApproval.InnerStepId column
+
+**EF Configurations:**
+- DROP InnerStep config (PE + Contract) → table dropped
+- WorkflowStep config + DeptId/PositionLevel + FK Restrict
+- DepartmentApprovals: restore simple unique non-filtered (Mig 19/20 filtered split reverse)
+
+**ApplicationDbContext:** DROP DbSet<*WorkflowStepInnerStep> × 2
+
+**Migration 21** `RefactorWorkflowToFlatModel` GỘP:
+- 4 ALTER (PE/Contract +CurrentStepIndex +RejectedAtStepIndex)
+- 2 ALTER (WorkflowStep +DepartmentId +PositionLevel) PE + Contract
+- DROP TABLE × 2 (PEWorkflowStepInnerSteps + WorkflowStepInnerSteps Mig 18+20)
+- DROP COLUMN × 2 (*DeptApproval.InnerStepId)
+- DROP filtered indexes Mig 19/20
+- RESTORE simple UNIQUE (TargetId, Phase, Dept, Stage) non-filtered × 2
+
+**Service rewrite (PE + Contract WorkflowService.TransitionAsync):**
+- DangSoanThao → ChoDuyet (Drafter trình, init idx=0)
+- ChoDuyet → ChoDuyet (advance idx per approve)
+- ChoDuyet → DaDuyet/DaPhatHanh (idx ≥ steps.Count → terminal, gen mã HĐ Contract)
+- ChoDuyet → DangSoanThao (Trả lại — save RejectedAtStepIndex)
+- ChoDuyet → TuChoi (Từ chối — khoá vĩnh viễn)
+- Resume Drafter (DangSoanThao + RejectedAtStepIndex≠null) → ChoDuyet jump-back
+- Match approver: actor.Dept == step.Dept AND actor.PositionLevel >= step.PositionLevel (OR-of-many cùng cấp/dept) OR Approvers.Kind=User|Role match
+- Admin role bypass policy
+
+**App CQRS:** WorkflowStepDto + WorkflowStepInput drop InnerStep, add DepartmentId/DepartmentName/PositionLevel (PE + Contract mirror).
+
+**Tests:**
+- DROP `PeNStageApprovalTests.cs` (6) + `ContractNStageApprovalTests.cs` (6) + `PeTwoStageApprovalTests.cs` (7) — legacy
+- UPDATE `PeWorkflowAdminTests` signature for new flat input
+- **96 → 77 test pass** (-19 legacy)
+
+**3-file rule** Mig 21 commit đủ (.cs + Designer + Snapshot).
+
+### Chunk B (`88a5be1`) — FE Designer + types
+
+**PeWorkflowsPage + WorkflowsPage rewrite (~210 LOC each):**
+- Drop InnerStepDto + EditInnerStep types
+- Drop PHASE_OPTIONS (auto-assign ChoDuyet=10 behind scenes)
+- StepDto + EditStep + departmentId, departmentName, positionLevel
+- Designer step UI rewrite: Tên + Phòng Select + Cấp Select + SLA + Approvers (Role/User optional fallback). Drop InnerSteps sub-section.
+- DefinitionCard view: badge Phòng emerald + Cấp NV/PP/TP violet
+- Save payload: phase=10 (ChoDuyet)
+- Hint amber: "User cùng Phòng + Cấp ≥ step → duyệt được (OR-of-many)"
+
+**types/purchaseEvaluation.ts (fe-admin + fe-user mirror):** + ChoDuyet=10 enum + label "Đang duyệt" + color amber. Legacy 2-6 + 98 keep.
+
+**Chunk C (FE PeWorkflowPanel) SKIPPED** — existing UI compatible (workflow.nextPhases BE-driven, 3-button Trả lại/Từ chối Session 14 reuse với target=DangSoanThao/TuChoi pattern).
+
+### Verify
+
+- ✅ dotnet build SolutionErp.slnx 0 error
+- ✅ dotnet ef database update Mig 21 LocalDB applied OK
+- ✅ dotnet test 77 pass (54 Domain + 23 Infra)
+- ✅ npm build fe-admin + fe-user pass
+
+### Cumulative sau Session 16
+
+| | Trước S16 | Sau S16 |
+|---|---:|---:|
+| BE LOC | ~15800 | ~15500 (-300 service simplified) |
+| Migrations | 20 | **21** |
+| DB tables | 57 | **55** (-2 InnerStep tables) |
+| Tests | 96 | **77** (-19 legacy N-stage/2-stage) |
+| FE pages | 32 | 32 (rewrite existing 2 designer) |
+
+## ⚠️ CẢNH BÁO Session 17+
+
+1. **UAT live test** — workflow flat ready. Tạo new workflow definition qua `/system/pe-workflows/:typeCode` với 3 phòng × N cấp setup. Verify Drafter trình → cấp 1 phòng A → cấp 2 phòng A → cấp 1 phòng B → ... → DaDuyet flow.
+
+2. **Old PE/HĐ pinned legacy workflow definitions** (phase=ChoPurchasing/ChoCCM/etc) — service rewrite chỉ handle ChoDuyet=10 + DangSoanThao/DaDuyet. Old data ở phase 2-6 sẽ stuck (admin manual transition required). Recommend: data migration script convert old workflow → new flat model (defer).
+
+3. **Approver explicit (Role/User Approvers list)** — fallback nếu user không match Dept+PositionLevel của step. Cho phép user external (không thuộc dept) duyệt qua Role match (vd Admin) hoặc User explicit.
+
+4. **Bypass cấp dưới cùng dept** — User TP với CanBypassReview=true cùng dept và PositionLevel cao hơn step.PositionLevel → duyệt qua. KHÔNG batch upsert NV+PP rows như Mig 18 N-stage trước (đơn giản hóa: 1 step approve = 1 row).
+
+5. **N-stage tests dropped** — 19 test legacy (Mig 18, 20 N-stage + Mig 16 2-stage). Có thể viết test mới cho flat workflow flow nếu UAT phát sinh bug. Defer.
+
+6. **Sample data N-stage seed** task vẫn pending (Session 14). Block trên DesignTime vs Runtime DB gotcha + DbInitializer seed flow.
+
+7. **Budget N-stage** vẫn defer (cần versioned WF migration trước).
+
+8. **schema-diagram §17-21 update** defer cron audit 2026-06-01.
 
 ## TL;DR Session 15 (07/05 — Tooltip diagnose + drastic refactor DEFER)