[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.Domain/PurchaseEvaluations/PurchaseEvaluationPhase.cs

@@ -1,25 +1,27 @@
 namespace SolutionErp.Domain.PurchaseEvaluations;
 
-// State machine PE — Session 16 drastic refactor (Mig 21):
-//   DangSoanThao → ChoDuyet (Drafter trình, init CurrentWorkflowStepIndex=0)
-//   ChoDuyet → ChoDuyet (advance step pointer mỗi lần approve)
-//   ChoDuyet → DaDuyet (last step done — terminal thành công)
-//   ChoDuyet → DangSoanThao (Trả lại — save RejectedAtStepIndex, Drafter sửa)
-//   ChoDuyet → TuChoi (Từ chối — terminal khoá phiếu)
+// State machine PE — Session 17 spec mới (5 trạng thái):
+//   DangSoanThao (Nháp)        ──Drafter trình──► ChoDuyet
+//   TraLai       (Trả lại)     ──Drafter sửa+gửi lại──► ChoDuyet (chạy lại từ Cấp 1 Bước 1)
+//   ChoDuyet     (Đã gửi duyệt) ──advance step pointer──► ChoDuyet
+//                              ──last step done──────────► DaDuyet (terminal)
+//                              ──Approver Trả lại────────► TraLai
+//                              ──Approver Từ chối────────► TuChoi (terminal)
 //   DangSoanThao → TuChoi (Drafter huỷ trước trình)
 //
-// LEGACY values 2-6 + 98 deprecated post-Mig 21 (data cũ vẫn đọc OK,
-// new workflow definitions chỉ dùng DangSoanThao/ChoDuyet/DaDuyet/TuChoi).
+// LEGACY values 2-6 deprecated post-Mig 21 (data cũ vẫn đọc OK).
+// TraLai=98: Session 17 restore làm primary state — Trả lại là Phase RIÊNG,
+// không revert về DangSoanThao như Mig 21.
 public enum PurchaseEvaluationPhase
 {
-    DangSoanThao = 1,
-    ChoPurchasing = 2,         // [LEGACY] deprecated
-    ChoDuAn = 3,               // [LEGACY] deprecated
-    ChoCCM = 4,                // [LEGACY] deprecated
-    ChoCEODuyetPA = 5,         // [LEGACY] deprecated
-    ChoCEODuyetNCC = 6,        // [LEGACY] deprecated
-    DaDuyet = 7,               // terminal thành công
-    ChoDuyet = 10,             // [Mig 21] generic intermediate, dùng CurrentWorkflowStepIndex tracking
-    TraLai = 98,               // [LEGACY] deprecated — Session 14 chốt thay bằng Trả lại = về DangSoanThao
-    TuChoi = 99,               // terminal từ chối — KHÔNG cho edit/thao tác
+    DangSoanThao = 1,           // Nháp
+    ChoPurchasing = 2,          // [LEGACY] deprecated
+    ChoDuAn = 3,                // [LEGACY] deprecated
+    ChoCCM = 4,                 // [LEGACY] deprecated
+    ChoCEODuyetPA = 5,          // [LEGACY] deprecated
+    ChoCEODuyetNCC = 6,         // [LEGACY] deprecated
+    DaDuyet = 7,                // Đã duyệt — terminal thành công
+    ChoDuyet = 10,              // Đã gửi duyệt — generic intermediate, CurrentWorkflowStepIndex tracking
+    TraLai = 98,                // Trả lại — Phase riêng, Drafter sửa rồi gửi lại chạy từ đầu
+    TuChoi = 99,                // Từ chối — terminal khoá phiếu, KHÔNG cho edit/thao tác
 }

src/Backend/SolutionErp.Domain/PurchaseEvaluations/PurchaseEvaluationPolicy.cs

@@ -38,6 +38,7 @@ public static class PurchaseEvaluationPolicies
     private static readonly Dictionary<PurchaseEvaluationPhase, TimeSpan?> DefaultSla = new()
     {
         [PurchaseEvaluationPhase.DangSoanThao] = TimeSpan.FromDays(3),
+        [PurchaseEvaluationPhase.TraLai] = TimeSpan.FromDays(3),
         [PurchaseEvaluationPhase.ChoPurchasing] = TimeSpan.FromDays(2),
         [PurchaseEvaluationPhase.ChoDuAn] = TimeSpan.FromDays(2),
         [PurchaseEvaluationPhase.ChoCCM] = TimeSpan.FromDays(2),
@@ -48,33 +49,37 @@ public static class PurchaseEvaluationPolicies
     };
 
     // A — DuyetNcc (3 step thực + Drafter soạn): Drafter → Purchasing → CCM → CEO
+    // Session 17 spec: Reject = về TraLai (Phase riêng, không revert DangSoanThao).
+    // Drafter từ TraLai gửi lại = entry point thứ 2 (mirror DangSoanThao → ChoPurchasing).
     public static readonly PurchaseEvaluationPolicy NccOnly = new(
         Name: "NccOnly",
         Description: "Duyệt NCC — 3 step (Purchasing → CCM → CEO). Không cần duyệt phương án.",
         Transitions: new Dictionary<(PurchaseEvaluationPhase, PurchaseEvaluationPhase), string[]>
         {
+            // Drafter trình từ Nháp HOẶC gửi lại từ Trả lại — cùng entry point.
             [(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.ChoPurchasing)] = [AppRoles.Drafter, AppRoles.DeptManager],
             [(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Drafter, AppRoles.DeptManager],
+            [(PurchaseEvaluationPhase.TraLai, PurchaseEvaluationPhase.ChoPurchasing)] = [AppRoles.Drafter, AppRoles.DeptManager],
+            [(PurchaseEvaluationPhase.TraLai, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Drafter, AppRoles.DeptManager],
 
-            // Phase trung gian: 3 hành động — Duyệt forward / Trả lại Drafter (DangSoanThao) / Từ chối hoàn toàn (TuChoi).
-            // Trả lại = smart reject pattern Mig 16 (set RejectedFromPhase + về DangSoanThao + Drafter sửa).
-            // Từ chối = phiếu khoá hoàn toàn (Phase=TuChoi → 17 handler Mig 16 lock edit).
+            // Phase trung gian: 3 hành động — Duyệt forward / Trả lại (TraLai Phase riêng) / Từ chối (TuChoi terminal).
             [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.ChoCCM)] = [AppRoles.Procurement],
-            [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.Procurement],
+            [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.TraLai)] = [AppRoles.Procurement],
             [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Procurement],
 
             [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.ChoCEODuyetNCC)] = [AppRoles.CostControl],
-            [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.CostControl],
+            [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.TraLai)] = [AppRoles.CostControl],
             [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.CostControl],
 
             [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.DaDuyet)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
-            [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
+            [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.TraLai)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
             [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
         },
         PhaseSla: DefaultSla,
         ActivePhases:
         [
             PurchaseEvaluationPhase.DangSoanThao,
+            PurchaseEvaluationPhase.TraLai,
             PurchaseEvaluationPhase.ChoPurchasing,
             PurchaseEvaluationPhase.ChoCCM,
             PurchaseEvaluationPhase.ChoCEODuyetNCC,
@@ -90,32 +95,35 @@ public static class PurchaseEvaluationPolicies
         {
             [(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.ChoPurchasing)] = [AppRoles.Drafter, AppRoles.DeptManager],
             [(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Drafter, AppRoles.DeptManager],
+            [(PurchaseEvaluationPhase.TraLai, PurchaseEvaluationPhase.ChoPurchasing)] = [AppRoles.Drafter, AppRoles.DeptManager],
+            [(PurchaseEvaluationPhase.TraLai, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Drafter, AppRoles.DeptManager],
 
-            // Phase trung gian: 3 hành động — Duyệt forward / Trả lại / Từ chối (xem comment NccOnly).
+            // Phase trung gian: 3 hành động — Duyệt forward / Trả lại (TraLai) / Từ chối (TuChoi).
             [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.ChoDuAn)] = [AppRoles.Procurement],
-            [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.Procurement],
+            [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.TraLai)] = [AppRoles.Procurement],
             [(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Procurement],
 
             [(PurchaseEvaluationPhase.ChoDuAn, PurchaseEvaluationPhase.ChoCCM)] = [AppRoles.ProjectManager],
-            [(PurchaseEvaluationPhase.ChoDuAn, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.ProjectManager],
+            [(PurchaseEvaluationPhase.ChoDuAn, PurchaseEvaluationPhase.TraLai)] = [AppRoles.ProjectManager],
             [(PurchaseEvaluationPhase.ChoDuAn, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.ProjectManager],
 
             [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.ChoCEODuyetPA)] = [AppRoles.CostControl],
-            [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.CostControl],
+            [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.TraLai)] = [AppRoles.CostControl],
             [(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.CostControl],
 
             [(PurchaseEvaluationPhase.ChoCEODuyetPA, PurchaseEvaluationPhase.ChoCEODuyetNCC)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
-            [(PurchaseEvaluationPhase.ChoCEODuyetPA, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
+            [(PurchaseEvaluationPhase.ChoCEODuyetPA, PurchaseEvaluationPhase.TraLai)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
             [(PurchaseEvaluationPhase.ChoCEODuyetPA, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
 
             [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.DaDuyet)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
-            [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.DangSoanThao)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
+            [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.TraLai)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
             [(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.TuChoi)] = [AppRoles.Director, AppRoles.AuthorizedSigner],
         },
         PhaseSla: DefaultSla,
         ActivePhases:
         [
             PurchaseEvaluationPhase.DangSoanThao,
+            PurchaseEvaluationPhase.TraLai,
             PurchaseEvaluationPhase.ChoPurchasing,
             PurchaseEvaluationPhase.ChoDuAn,
             PurchaseEvaluationPhase.ChoCCM,
@@ -183,30 +191,45 @@ public static class PurchaseEvaluationPolicyRegistry
                 transitions[(prev.Value, s.Phase)] = roles;
                 if (userIds.Length > 0) userTransitions[(prev.Value, s.Phase)] = userIds;
 
-                // 3 hành động phase trung gian — Duyệt forward + Trả lại Drafter + Từ chối hoàn toàn
+                // Mirror: TraLai → s.Phase cho cả Drafter (resubmit từ Trả lại = entry point thứ 2)
+                if (prev.Value == PurchaseEvaluationPhase.DangSoanThao)
+                {
+                    transitions.TryAdd((PurchaseEvaluationPhase.TraLai, s.Phase), roles);
+                    if (userIds.Length > 0)
+                        userTransitions.TryAdd((PurchaseEvaluationPhase.TraLai, s.Phase), userIds);
+                }
+
+                // 3 hành động phase trung gian — Duyệt forward + Trả lại (TraLai) + Từ chối (TuChoi)
                 if (prev.Value != PurchaseEvaluationPhase.DangSoanThao && s.Phase != PurchaseEvaluationPhase.DangSoanThao)
                 {
-                    transitions.TryAdd((s.Phase, PurchaseEvaluationPhase.DangSoanThao), roles);
+                    transitions.TryAdd((s.Phase, PurchaseEvaluationPhase.TraLai), roles);
                     transitions.TryAdd((s.Phase, PurchaseEvaluationPhase.TuChoi), roles);
                     if (userIds.Length > 0)
                     {
-                        userTransitions.TryAdd((s.Phase, PurchaseEvaluationPhase.DangSoanThao), userIds);
+                        userTransitions.TryAdd((s.Phase, PurchaseEvaluationPhase.TraLai), userIds);
                         userTransitions.TryAdd((s.Phase, PurchaseEvaluationPhase.TuChoi), userIds);
                     }
                 }
             }
             prev = s.Phase;
         }
-        // First step (DangSoanThao) — Drafter có thể TuChoi (huỷ phiếu)
+        // First step (DangSoanThao) — Drafter có thể TuChoi (huỷ phiếu).
+        // Tương tự cho TraLai — Drafter có thể TuChoi luôn từ Trả lại.
         if (steps.Count > 0)
+        {
             transitions.TryAdd((steps[0].Phase, PurchaseEvaluationPhase.TuChoi),
                 [AppRoles.Drafter, AppRoles.DeptManager]);
+            transitions.TryAdd((PurchaseEvaluationPhase.TraLai, PurchaseEvaluationPhase.TuChoi),
+                [AppRoles.Drafter, AppRoles.DeptManager]);
+        }
 
-        // Terminal states always available
+        // Terminal states always available + TraLai phase
         if (!activePhases.Contains(PurchaseEvaluationPhase.TuChoi))
             activePhases.Add(PurchaseEvaluationPhase.TuChoi);
         if (!activePhases.Contains(PurchaseEvaluationPhase.DaDuyet))
             activePhases.Add(PurchaseEvaluationPhase.DaDuyet);
+        if (!activePhases.Contains(PurchaseEvaluationPhase.TraLai))
+            activePhases.Add(PurchaseEvaluationPhase.TraLai);
 
         return new PurchaseEvaluationPolicy(
             Name: $"{def.Code}-v{def.Version:D2}",