[CLAUDE] Docs: chốt Session 15 wrap-up — tooltip diagnose + drastic refactor DEFER

Session 15 (2026-05-07) docs update:

STATUS.md:
- Last updated Session 15 (1 commit `835cc7f` tooltip + working tree
  drastic refactor revert)
- Recently Done row Session 15 chi tiết (diagnose + plan drastic +
  attempt 12 file edits + REVERT decision)

HANDOFF.md:
- TL;DR Session 15 prepend với 2 phần: Diagnose tooltip + Drastic
  refactor DEFER decision
- 4 cảnh báo Session 16+: Drastic refactor pending (8-10h dedicated
  hoặc fallback Approach Y), Task 2 sample seed pending, schema-diagram
  defer cron audit, Hard blockers giữ nguyên

migration-todos.md:
- Phase 9 + Session 15 block với 1 task done (tooltip) + 1 defer
  (drastic refactor) + memory entry note
- Defer Session 16+ list

Session log NEW `2026-05-07-2600-tooltip-defer-drastic.md`:
- Bối cảnh user UAT báo button silent disabled
- Phần 1 — Diagnose tooltip (root cause + fix UX + "trùng ID" KHÔNG
  phải bug FE)
- Phần 2 — Plan drastic refactor flat workflow → DEFER:
  * User spec mới (Phòng × Cấp × Users[] flat)
  * Plan 6 chunk + estimate scope realistic ~8-10h
  * Attempt 12 file working tree edits → REVERT decision
  * Memory entry capture decision rule
- Plan organization sau S15 (defer queue)

Memory entry NEW `feedback_drastic_refactor_scope.md`:
- Quy tắc: drastic refactor cần dedicated session, scope conservative
  2x buffer
- Anti-patterns mid-session big refactor + commit broken state
- Defer pattern (revert working tree → document → memory entry → surface
  trade-off cho user)
- Cross-ref `feedback_per_chunk_commit.md` discipline

🎉 Session 15 wrap-up. Cumulative since session start (13h17): 16 commit
(1 button removal + 6 PE N-stage + 5 Contract N-stage + 1 3-button +
1 Session 14 wrap-up + 1 tooltip + 1 Session 15 wrap-up).

Verify: dotnet test 96 pass + working tree clean.

Defer Session 16+ priority order:
1. Drastic refactor flat workflow (dedicated session ~8-10h)
   OR fallback Approach Y (FE flat UI 5 phòng, 1-2h)
2. Task 2 sample data seed N-stage
3. Hard blockers Ops (UAT, SMTP, etc.)

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

docs/HANDOFF.md

@@ -1,6 +1,58 @@
 # HANDOFF — Brief 5 phút cho session tiếp theo
 
-**Last updated:** 2026-05-07 (Session 14 — **PE 3-button workflow Duyệt/Trả lại/Từ chối — Domain policy expand + Service tách reject 2 case + FE 3-button + 1 test mới = 96 pass. 1 commit `0d77698`. Task 2 sample seed defer (DesignTime vs Runtime DB gotcha + API exit sớm).**)
+**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.**)
+
+## TL;DR Session 15 (07/05 — Tooltip diagnose + drastic refactor DEFER)
+
+User UAT live screenshot báo button "Lưu & Gửi Duyệt" KHÔNG hoạt động + suy đoán "trùng ID" giữa các phiếu.
+
+**Diagnose (commit `835cc7f`):**
+- Root cause: button silent disabled khi `evaluation.workflow.nextPhases` không có forward phase (chỉ TuChoi/TraLai). Cause khả năng: workflow definition pinned thiếu adjacent step → `policy.NextPhasesFrom(DangSoanThao)` return empty.
+- Improvement: tooltip + dialog hiển thị reason rõ ràng:
+  - `submitDisabledReason` text: "Phiếu đã ở phase X — chỉ Bản nháp/Trả lại mới sửa+gửi" / "Workflow không có phase tiếp theo từ X. Liên hệ admin kiểm tra cấu hình"
+  - Button title attribute → hover show reason hoặc forward phase label
+  - Dialog confirm show forward phase explicit ("Sẽ chuyển sang Chờ Purchasing")
+- Mirror fe-admin + fe-user. Build pass cả 2. KHÔNG đụng BE — chỉ FE diagnostic UX.
+- "Trùng ID" KHÔNG phải bug FE — `PurchaseEvaluationWorkspacePage` URL state đúng, mỗi PE row unique GUID + MaPhieu. Suy đoán user do button silent.
+
+**Plan drastic refactor → DEFER:**
+
+User confirm "bỏ phase enum hoàn toàn, dùng ChoDuyet=10 đơn nhất + currentStepIndex tracking" — refactor workflow từ phase-based + InnerStep nested model sang flat WorkflowStep model (mỗi step = Phòng × Cấp + Approvers users).
+
+Edit working tree 12 files (Domain entities + EF Configurations + DbContext):
+- Phase enum +ChoDuyet=10, legacy values 2-6 deprecated
+- WorkflowStep +DepartmentId, +PositionLevel
+- Drop class WorkflowStepInnerStep + nav (PE + Contract)
+- PE/Contract +CurrentWorkflowStepIndex int?, +RejectedAtStepIndex int?
+- *DepartmentApproval drop InnerStepId column
+- EF Configurations: drop InnerStep config + nav, restore simple unique non-filtered
+- DbContext: drop DbSet<WorkflowStepInnerStep> × 2
+
+Reality check scope realistic ~8-10h:
+1. Domain + EF + DbContext (~50min) ✓ done in working tree
+2. PolicyRegistry rewrite PE+Contract (~45min)
+3. App CQRS DTOs rewrite (~45min)
+4. Service rewrite PE+Contract (~2-3h)
+5. Tests rewrite — drop 12 N-stage tests + update remaining (~1.5h)
+6. Migration 21 + LocalDB apply + verify (~30min)
+7. FE Designer rewrite (~1.5h)
+8. FE PeWorkflowPanel + workflow timeline (~1h)
+9. Docs/Skill update (~45min)
+
+Vượt session boundary + risk session deep ~30 commits → **REVERT working tree** về `835cc7f` clean state. Test 96 pass intact.
+
+**Decision memorized:** add memory `feedback_drastic_refactor_scope.md` — drastic refactor cần dedicated session, scope estimation conservative (2x buffer), tránh mid-session big refactor.
+
+## ⚠️ CẢNH BÁO Session 16+
+
+1. **Drastic refactor flat workflow chưa làm — DEFER** với plan chi tiết. Khi resume:
+   - Plan kỹ 6 chunk per-commit
+   - Buffer 2x estimate (~16h thực tế)
+   - Tests rewrite biggest risk
+   - Hoặc fall back Approach Y (FE Designer flat UI giới hạn 5 phòng) ROI 1-2h nếu user OK trade-off
+2. **Task 2 sample data seed N-stage** vẫn pending (block trên DesignTime vs Runtime DB gotcha + DbInitializer seed flow)
+3. **schema-diagram §17-19 Mig 18-20** vẫn defer cron audit 2026-06-01
+4. **Hard blockers Ops** giữ nguyên 6 task
 
 ## TL;DR Session 14 (07/05 — PE 3-button approval workflow)