[CLAUDE] Workflow: State machine 5 trạng thái — Trả lại = Phase riêng

Session 17 spec: chốt 5 trạng thái phiếu PE/HĐ/Budget theo state diagram:
  Nháp ─trình──► Đã gửi duyệt ─approve cấp cuối──► Đã duyệt (terminal)
                              ├─ Trả lại ────────► Trả lại
                              └─ Từ chối ────────► Từ chối (terminal)
  Trả lại ──Drafter sửa+gửi lại──► Đã gửi duyệt (chạy LẠI từ đầu)

Khác Mig 21 (Session 16): bỏ smart-reject jump-back. Trả lại = Phase
RIÊNG (TraLai=98), không revert về DangSoanThao + không jump-back step.
Drafter từ TraLai gửi lại như case Nháp — workflow chạy lại từ Cấp 1
Bước 1 (Option A diagram chốt với user).

BE Domain:
- ContractPhase + TraLai = 98
- BudgetPhase + TraLai = 98
- PurchaseEvaluationPhase: TraLai=98 đổi từ [LEGACY deprecated] thành
  primary state. Comment update enum docs cho cả 3.

BE Policy (PE/HĐ/Budget):
- Reject transitions trỏ về TraLai (thay DangSoanThao)
- Mirror entry transitions: TraLai → next phase (cho Drafter resubmit)
- ActivePhases thêm TraLai
- FromDefinition mirror: TraLai → step.Phase + reject → TraLai
- DefaultSla cho TraLai = same as DangSoanThao

BE Service (PE + Contract):
- Reject branch: target=TuChoi giữ; else set Phase=TraLai, clear
  CurrentWorkflowStepIndex=null
- Bỏ ResumeAfterReject branch + RejectedAtStepIndex/RejectedFromPhase
  assignment (DB column giữ deprecated cho data cũ)
- Drafter trình branch: từ DangSoanThao HOẶC TraLai → ChoDuyet, init
  CurrentWorkflowStepIndex=0 (cùng entry point, chạy lại từ đầu)
- Notification: TraLai when fromPhase=ChoDuyet → "bị trả lại"
- Budget Handler: simplify reject → TraLai, bỏ smart-reject + isResuming

BE Tests update:
- WorkflowPolicyTests: Standard_RejectFromCCM → TraLai (rename + assert)
  + Standard_TraLai_To_DangGopY_Allowed_For_Drafter (new)
- PurchaseEvaluationPolicyTests: BothPolicies_RejectFromCCM → TraLai
  + BothPolicies_TraLai_To_ChoPurchasing_AllowedForDrafter (new theory)
- BudgetPolicyTests: Default_CostControl_ChoCCM_To_TraLai (rename)
  + ActivePhases All6States (was All5) + NextPhasesFrom_TraLai (new)
  + NextPhasesFrom_ChoCEO_Includes_DaDuyet_And_TraLai (rename)
- 77 → 81 test pass (+4 tests TraLai entry point)

FE rename "Bản nháp" → "Nháp" (cả 2 app + types):
- types/purchaseEvaluation.ts: PurchaseEvaluationPhaseLabel 1=Nháp,
  10=Đã gửi duyệt. PeDisplayStatus.BanNhap → Nhap (key + value).
  PhaseLabel/Color cho TraLai update active.
- types/contracts.ts: +ChoDuyet=10, +TraLai=98 const + label/color.
  Phase 2 'Đang soạn thảo' → 'Nháp'.
- types/budget.ts: +TraLai=98 const + label/color. Phase 1 → 'Nháp'.
- PeListPanel + PurchaseEvaluationsListPage filter dropdown: Nhap +
  TraLai map đúng phase value.

BE label maps update consistent:
- ContractExcelExporter PhaseLabel: DangSoanThao → "Nháp" + add ChoDuyet/
  TraLai entries.
- PeWorkflowAdminFeatures + WorkflowAdminFeatures PhaseLabels: same.

Verify: dotnet test 81 pass · npm build × 2 app pass · BE 0 error.

Field RejectedAtStepIndex/RejectedFromPhase giữ DB column (nullable,
không set value mới). Cleanup migration sau.

src/Backend/SolutionErp.Application/Budgets/BudgetFeatures.cs

@@ -136,29 +136,24 @@ public class TransitionBudgetCommandHandler(
         var entity = await db.Budgets.FirstOrDefaultAsync(x => x.Id == request.Id, ct)
             ?? throw new NotFoundException("Budget", request.Id);
 
-        // ===== Smart reject + resume (Phase 9 — Migration 16) =====
+        // ===== Reject → TraLai (Session 17 spec mới) =====
+        // Bỏ smart-reject jump-back. Trả lại = Phase riêng (TraLai).
+        // Drafter từ TraLai gửi lại như Nháp — Policy `(TraLai, ChoCCM)` đã wire.
+        // Field RejectedFromPhase giữ DB column nhưng KHÔNG set value mới (data cũ vẫn đọc).
         var fromPhase = entity.Phase;
         var targetPhase = request.TargetPhase;
-        var isResumingAfterReject = request.Decision == ApprovalDecision.Approve
-            && fromPhase == BudgetPhase.DangSoanThao
-            && entity.RejectedFromPhase != null;
 
-        if (request.Decision == ApprovalDecision.Reject)
+        if (request.Decision == ApprovalDecision.Reject && targetPhase != BudgetPhase.TuChoi)
         {
-            entity.RejectedFromPhase = fromPhase;
-            targetPhase = BudgetPhase.DangSoanThao;
-        }
-        else if (isResumingAfterReject)
-        {
-            targetPhase = entity.RejectedFromPhase!.Value;
-            entity.RejectedFromPhase = null;
+            // Trả lại — override target → TraLai
+            targetPhase = BudgetPhase.TraLai;
         }
 
         var policy = BudgetPolicies.Default;
         var isAdmin = currentUser.Roles.Contains(AppRoles.Admin);
 
-        // Policy guard — bypass khi resume sau reject.
-        if (!isAdmin && !isResumingAfterReject
+        // Policy guard
+        if (!isAdmin
             && !policy.IsTransitionAllowed(fromPhase, targetPhase, currentUser.Roles))
             throw new ForbiddenException(
                 $"Role không đủ quyền chuyển {fromPhase} → {targetPhase}.");
@@ -168,8 +163,8 @@ public class TransitionBudgetCommandHandler(
         // nhưng giữ consistent UX 3 module.
         if (request.Decision == ApprovalDecision.Approve
             && targetPhase != BudgetPhase.DangSoanThao
+            && targetPhase != BudgetPhase.TraLai
             && targetPhase != BudgetPhase.TuChoi
-            && !isResumingAfterReject
             && !isAdmin
             && currentUser.UserId is Guid actorUid)
         {

src/Backend/SolutionErp.Application/Contracts/WorkflowAdminFeatures.cs

@@ -74,7 +74,7 @@ public class GetWorkflowAdminOverviewQueryHandler(
 
     private static readonly Dictionary<ContractPhase, string> PhaseLabels = new()
     {
-        [ContractPhase.DangSoanThao] = "Đang soạn thảo",
+        [ContractPhase.DangSoanThao] = "Nháp",
         [ContractPhase.DangGopY] = "Đang góp ý",
         [ContractPhase.DangDamPhan] = "Đang đàm phán",
         [ContractPhase.DangInKy] = "Đang in ký",
@@ -82,6 +82,9 @@ public class GetWorkflowAdminOverviewQueryHandler(
         [ContractPhase.DangTrinhKy] = "Đang trình ký",
         [ContractPhase.DangDongDau] = "Đang đóng dấu",
         [ContractPhase.DaPhatHanh] = "Đã phát hành",
+        [ContractPhase.ChoDuyet] = "Đã gửi duyệt",
+        [ContractPhase.TraLai] = "Trả lại",
+        [ContractPhase.TuChoi] = "Từ chối",
     };
 
     public async Task<WorkflowAdminOverviewDto> Handle(GetWorkflowAdminOverviewQuery request, CancellationToken ct)

src/Backend/SolutionErp.Application/PurchaseEvaluations/PeWorkflowAdminFeatures.cs

@@ -69,13 +69,16 @@ public class GetPeWorkflowAdminOverviewQueryHandler(
 
     private static readonly Dictionary<PurchaseEvaluationPhase, string> PhaseLabels = new()
     {
-        [PurchaseEvaluationPhase.DangSoanThao] = "Đang soạn thảo",
+        [PurchaseEvaluationPhase.DangSoanThao] = "Nháp",
         [PurchaseEvaluationPhase.ChoPurchasing] = "Chờ Purchasing",
         [PurchaseEvaluationPhase.ChoDuAn] = "Chờ Dự án",
         [PurchaseEvaluationPhase.ChoCCM] = "Chờ CCM",
         [PurchaseEvaluationPhase.ChoCEODuyetPA] = "Chờ CEO duyệt PA",
         [PurchaseEvaluationPhase.ChoCEODuyetNCC] = "Chờ CEO duyệt NCC",
+        [PurchaseEvaluationPhase.ChoDuyet] = "Đã gửi duyệt",
         [PurchaseEvaluationPhase.DaDuyet] = "Đã duyệt",
+        [PurchaseEvaluationPhase.TraLai] = "Trả lại",
+        [PurchaseEvaluationPhase.TuChoi] = "Từ chối",
     };
 
     public async Task<PeWorkflowAdminOverviewDto> Handle(GetPeWorkflowAdminOverviewQuery request, CancellationToken ct)