diff --git a/.gitea/workflows/deploy.yml b/.gitea/workflows/deploy.yml
index 02bfa04..b080165 100644
--- a/.gitea/workflows/deploy.yml
+++ b/.gitea/workflows/deploy.yml
@@ -29,6 +29,30 @@ jobs:
           & 'C:\Program Files\nodejs\node.exe' --version
           & 'C:\Program Files\nodejs\npm.cmd' --version
 
+      # ============== TEST GATE ==============
+      # Run unit tests TRƯỚC build/publish/deploy. Test fail → exit non-zero
+      # → toàn bộ job stop, KHÔNG deploy. Phase 1 chỉ Domain layer (~54 test
+      # phase machine + policy registry). Mở rộng Application/Infra/Api
+      # khi có nhu cầu (xem docs/changelog/migration-todos.md).
+      - name: Run unit tests (Domain)
+        shell: powershell
+        run: |
+          & 'C:\Program Files\dotnet\dotnet.exe' test tests/SolutionErp.Domain.Tests/SolutionErp.Domain.Tests.csproj `
+            --configuration Release `
+            --logger "trx;LogFileName=domain-tests.trx" `
+            --results-directory test-results
+          if ($LASTEXITCODE -ne 0) { exit $LASTEXITCODE }
+
+      - name: Upload test results
+        if: always()
+        continue-on-error: true   # nếu Gitea runner chưa có upload-artifact action, skip không block deploy
+        uses: actions/upload-artifact@v4
+        with:
+          name: test-results
+          path: test-results/*.trx
+          retention-days: 14
+
+      # ============== BUILD ==============
       - name: Build backend
         shell: powershell
         run: |
diff --git a/SolutionErp.slnx b/SolutionErp.slnx
index 9e44d7a..d616e0c 100644
--- a/SolutionErp.slnx
+++ b/SolutionErp.slnx
@@ -6,4 +6,7 @@
     <Project Path="src/Backend/SolutionErp.Domain/SolutionErp.Domain.csproj" />
     <Project Path="src/Backend/SolutionErp.Infrastructure/SolutionErp.Infrastructure.csproj" />
   </Folder>
+  <Folder Name="/tests/">
+    <Project Path="tests/SolutionErp.Domain.Tests/SolutionErp.Domain.Tests.csproj" />
+  </Folder>
 </Solution>
diff --git a/tests/SolutionErp.Domain.Tests/Budgets/BudgetPolicyTests.cs b/tests/SolutionErp.Domain.Tests/Budgets/BudgetPolicyTests.cs
new file mode 100644
index 0000000..af71068
--- /dev/null
+++ b/tests/SolutionErp.Domain.Tests/Budgets/BudgetPolicyTests.cs
@@ -0,0 +1,134 @@
+using SolutionErp.Domain.Budgets;
+using SolutionErp.Domain.Identity;
+
+namespace SolutionErp.Domain.Tests.Budgets;
+
+// Tests cho BudgetPolicy (hardcoded simple 3-step Default).
+// Chống regression khi BudgetPhase enum thêm phase hoặc role mapping bị edit.
+
+public class BudgetPolicyTests
+{
+    [Fact]
+    public void Default_Drafter_DangSoanThao_To_ChoCCM_Allowed()
+    {
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.DangSoanThao, BudgetPhase.ChoCCM,
+                [AppRoles.Drafter])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Default_DeptManager_DangSoanThao_To_ChoCCM_Allowed()
+    {
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.DangSoanThao, BudgetPhase.ChoCCM,
+                [AppRoles.DeptManager])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Default_RandomRole_DangSoanThao_To_ChoCCM_Denied()
+    {
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.DangSoanThao, BudgetPhase.ChoCCM,
+                [AppRoles.Procurement])
+            .Should().BeFalse();
+    }
+
+    [Fact]
+    public void Default_CostControl_ChoCCM_To_ChoCEO_Allowed()
+    {
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.ChoCCM, BudgetPhase.ChoCEO,
+                [AppRoles.CostControl])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Default_CostControl_ChoCCM_To_DangSoanThao_Allowed()
+    {
+        // Trả về Drafter
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.ChoCCM, BudgetPhase.DangSoanThao,
+                [AppRoles.CostControl])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Default_Director_ChoCEO_To_DaDuyet_Allowed()
+    {
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.ChoCEO, BudgetPhase.DaDuyet,
+                [AppRoles.Director])
+            .Should().BeTrue();
+
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.ChoCEO, BudgetPhase.DaDuyet,
+                [AppRoles.AuthorizedSigner])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Default_CCM_Cannot_Approve_To_DaDuyet()
+    {
+        // CCM chỉ chuyển đến ChoCEO, không tự duyệt thành DaDuyet
+        BudgetPolicies.Default
+            .IsTransitionAllowed(BudgetPhase.ChoCEO, BudgetPhase.DaDuyet,
+                [AppRoles.CostControl])
+            .Should().BeFalse();
+    }
+
+    [Fact]
+    public void Default_DaDuyet_NoFurtherTransitions()
+    {
+        BudgetPolicies.Default.NextPhasesFrom(BudgetPhase.DaDuyet)
+            .Should().BeEmpty("DaDuyet là terminal");
+    }
+
+    [Fact]
+    public void Default_TuChoi_NoFurtherTransitions()
+    {
+        BudgetPolicies.Default.NextPhasesFrom(BudgetPhase.TuChoi)
+            .Should().BeEmpty("TuChoi là terminal");
+    }
+
+    [Fact]
+    public void Default_ActivePhases_Includes_All5States()
+    {
+        BudgetPolicies.Default.ActivePhases.Should().BeEquivalentTo(new[]
+        {
+            BudgetPhase.DangSoanThao, BudgetPhase.ChoCCM,
+            BudgetPhase.ChoCEO, BudgetPhase.DaDuyet, BudgetPhase.TuChoi,
+        });
+    }
+
+    [Fact]
+    public void Default_NextPhasesFrom_DangSoanThao_Includes_ChoCCM_And_TuChoi()
+    {
+        var next = BudgetPolicies.Default.NextPhasesFrom(BudgetPhase.DangSoanThao);
+        next.Should().Contain(BudgetPhase.ChoCCM);
+        next.Should().Contain(BudgetPhase.TuChoi);
+    }
+
+    [Fact]
+    public void Default_NextPhasesFrom_ChoCEO_Includes_DaDuyet_And_DangSoanThao()
+    {
+        var next = BudgetPolicies.Default.NextPhasesFrom(BudgetPhase.ChoCEO);
+        next.Should().Contain(BudgetPhase.DaDuyet);
+        next.Should().Contain(BudgetPhase.DangSoanThao);
+    }
+
+    // SLA — chống regression khi đổi phase deadline accidentally
+    [Fact]
+    public void Default_SlaDeadlines_Match_Spec()
+    {
+        BudgetPolicies.Default.PhaseSla[BudgetPhase.DangSoanThao]
+            .Should().Be(TimeSpan.FromDays(5));
+        BudgetPolicies.Default.PhaseSla[BudgetPhase.ChoCCM]
+            .Should().Be(TimeSpan.FromDays(3));
+        BudgetPolicies.Default.PhaseSla[BudgetPhase.ChoCEO]
+            .Should().Be(TimeSpan.FromDays(2));
+        BudgetPolicies.Default.PhaseSla[BudgetPhase.DaDuyet]
+            .Should().BeNull("Terminal phase không có SLA");
+    }
+}
diff --git a/tests/SolutionErp.Domain.Tests/Contracts/WorkflowPolicyTests.cs b/tests/SolutionErp.Domain.Tests/Contracts/WorkflowPolicyTests.cs
new file mode 100644
index 0000000..3d3242f
--- /dev/null
+++ b/tests/SolutionErp.Domain.Tests/Contracts/WorkflowPolicyTests.cs
@@ -0,0 +1,227 @@
+using SolutionErp.Domain.Contracts;
+using SolutionErp.Domain.Identity;
+
+namespace SolutionErp.Domain.Tests.Contracts;
+
+// Tests for WorkflowPolicy state machine — pure functions, no DB / IO.
+// Mục tiêu: chống regression khi policy table bị edit nhầm hoặc khi ContractPhase
+// enum thêm phase mới mà quên update policy. ALL fast in-memory.
+
+public class WorkflowPolicyTests
+{
+    // ===== Standard policy (HĐ Thầu phụ / NCC / Giao khoán — full CCM) =====
+
+    [Fact]
+    public void Standard_Drafter_DangSoanThao_To_DangGopY_Allowed()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY,
+                [AppRoles.Drafter])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Standard_DeptManager_DangSoanThao_To_DangGopY_Allowed()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY,
+                [AppRoles.DeptManager])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Standard_RandomRole_DangSoanThao_To_DangGopY_Denied()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY,
+                [AppRoles.Procurement])
+            .Should().BeFalse();
+    }
+
+    [Fact]
+    public void Standard_HasCcmPhase_InActivePhases()
+    {
+        WorkflowPolicies.Standard.HasPhase(ContractPhase.DangKiemTraCCM)
+            .Should().BeTrue("Standard policy phải có CCM phase");
+    }
+
+    [Fact]
+    public void Standard_CcmRole_DangKiemTraCCM_To_DangTrinhKy_Allowed()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangKiemTraCCM, ContractPhase.DangTrinhKy,
+                [AppRoles.CostControl])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Standard_DangTrinhKy_To_DangDongDau_RequiresDirectorOrSigner()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangTrinhKy, ContractPhase.DangDongDau,
+                [AppRoles.Director])
+            .Should().BeTrue();
+
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangTrinhKy, ContractPhase.DangDongDau,
+                [AppRoles.AuthorizedSigner])
+            .Should().BeTrue();
+
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangTrinhKy, ContractPhase.DangDongDau,
+                [AppRoles.CostControl])
+            .Should().BeFalse();
+    }
+
+    [Fact]
+    public void Standard_HrAdmin_DangDongDau_To_DaPhatHanh_Allowed()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangDongDau, ContractPhase.DaPhatHanh,
+                [AppRoles.HrAdmin])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void Standard_FromTerminal_DaPhatHanh_NoFurtherTransitions()
+    {
+        WorkflowPolicies.Standard.NextPhasesFrom(ContractPhase.DaPhatHanh)
+            .Should().BeEmpty("DaPhatHanh là terminal — không transition tiếp");
+    }
+
+    [Fact]
+    public void Standard_RejectFromCCM_GoesBackToDraft()
+    {
+        WorkflowPolicies.Standard
+            .IsTransitionAllowed(ContractPhase.DangKiemTraCCM, ContractPhase.DangSoanThao,
+                [AppRoles.CostControl])
+            .Should().BeTrue("CCM có quyền reject về Drafter");
+    }
+
+    [Fact]
+    public void Standard_NextPhasesFrom_Draft_Includes_DangGopY_And_TuChoi()
+    {
+        var next = WorkflowPolicies.Standard.NextPhasesFrom(ContractPhase.DangSoanThao);
+        next.Should().Contain(ContractPhase.DangGopY);
+        next.Should().Contain(ContractPhase.TuChoi);
+    }
+
+    // ===== SkipCcm policy (HĐ Dịch vụ / Mua bán / Nguyên tắc — bỏ phase CCM) =====
+
+    [Fact]
+    public void SkipCcm_DoesNotHave_DangKiemTraCCM_Phase()
+    {
+        WorkflowPolicies.SkipCcm.HasPhase(ContractPhase.DangKiemTraCCM)
+            .Should().BeFalse("SkipCcm policy bypass CCM phase");
+    }
+
+    [Fact]
+    public void SkipCcm_DangInKy_GoesDirectlyTo_DangTrinhKy()
+    {
+        WorkflowPolicies.SkipCcm
+            .IsTransitionAllowed(ContractPhase.DangInKy, ContractPhase.DangTrinhKy,
+                [AppRoles.Drafter])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void SkipCcm_NoTransition_To_DangKiemTraCCM()
+    {
+        WorkflowPolicies.SkipCcm
+            .IsTransitionAllowed(ContractPhase.DangInKy, ContractPhase.DangKiemTraCCM,
+                [AppRoles.Drafter])
+            .Should().BeFalse();
+    }
+
+    // ===== Registry mapping per ContractType =====
+
+    [Theory]
+    [InlineData(ContractType.HopDongThauPhu, "Standard")]
+    [InlineData(ContractType.HopDongGiaoKhoan, "Standard")]
+    [InlineData(ContractType.HopDongNhaCungCap, "Standard")]
+    [InlineData(ContractType.HopDongDichVu, "SkipCcm")]
+    [InlineData(ContractType.HopDongMuaBan, "SkipCcm")]
+    [InlineData(ContractType.HopDongNguyenTacNCC, "SkipCcm")]
+    [InlineData(ContractType.HopDongNguyenTacDichVu, "SkipCcm")]
+    public void Registry_DefaultPolicyName_MapsCorrectly(ContractType type, string expectedName)
+    {
+        WorkflowPolicyRegistry.DefaultPolicyNameFor(type)
+            .Should().Be(expectedName);
+    }
+
+    [Fact]
+    public void Registry_ForContract_BypassFlag_OverridesPolicy()
+    {
+        var contract = new Contract
+        {
+            Type = ContractType.HopDongThauPhu,   // mặc định Standard
+            BypassProcurementAndCCM = true,        // override → SkipCcm
+        };
+        WorkflowPolicyRegistry.ForContract(contract).Name
+            .Should().Be("SkipCcm");
+    }
+
+    // ===== FromDefinition (versioned admin-authored) =====
+
+    [Fact]
+    public void FromDefinition_BuildsPolicy_FromOrderedSteps()
+    {
+        var def = new WorkflowDefinition
+        {
+            Code = "QT-TEST",
+            Version = 1,
+            Name = "Test workflow",
+            ContractType = ContractType.HopDongMuaBan,
+            Steps =
+            [
+                new WorkflowStep { Order = 1, Phase = ContractPhase.DangSoanThao, Name = "Soạn",
+                    Approvers = [new WorkflowStepApprover { Kind = WorkflowApproverKind.Role, AssignmentValue = AppRoles.Drafter }] },
+                new WorkflowStep { Order = 2, Phase = ContractPhase.DangGopY, Name = "Góp ý",
+                    Approvers = [new WorkflowStepApprover { Kind = WorkflowApproverKind.Role, AssignmentValue = AppRoles.ProjectManager }] },
+                new WorkflowStep { Order = 3, Phase = ContractPhase.DaPhatHanh, Name = "Phát hành",
+                    Approvers = [new WorkflowStepApprover { Kind = WorkflowApproverKind.Role, AssignmentValue = AppRoles.HrAdmin }] },
+            ],
+        };
+        var policy = WorkflowPolicyRegistry.FromDefinition(def);
+
+        policy.Name.Should().Be("QT-TEST-v01");
+        policy.IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY, [AppRoles.ProjectManager])
+            .Should().BeTrue();
+        policy.IsTransitionAllowed(ContractPhase.DangGopY, ContractPhase.DaPhatHanh, [AppRoles.HrAdmin])
+            .Should().BeTrue();
+        policy.HasPhase(ContractPhase.TuChoi).Should().BeTrue("TuChoi luôn auto-thêm vào ActivePhases");
+    }
+
+    [Fact]
+    public void FromDefinition_UserKindApprover_PopulatesUserTransitions()
+    {
+        var userId = Guid.NewGuid().ToString();
+        var def = new WorkflowDefinition
+        {
+            Code = "QT-TEST",
+            Version = 1,
+            Name = "Test workflow user-kind",
+            ContractType = ContractType.HopDongMuaBan,
+            Steps =
+            [
+                new WorkflowStep { Order = 1, Phase = ContractPhase.DangSoanThao, Name = "Soạn", Approvers = [] },
+                new WorkflowStep { Order = 2, Phase = ContractPhase.DangGopY, Name = "Góp ý",
+                    Approvers = [new WorkflowStepApprover { Kind = WorkflowApproverKind.User, AssignmentValue = userId }] },
+            ],
+        };
+        var policy = WorkflowPolicyRegistry.FromDefinition(def);
+
+        // Role nào cũng deny vì step 2 chỉ có User-kind
+        policy.IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY,
+                [AppRoles.Drafter])
+            .Should().BeFalse();
+        // Đúng user-id → allow
+        policy.IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY,
+                [AppRoles.Drafter], Guid.Parse(userId))
+            .Should().BeTrue();
+        // Sai user-id → deny
+        policy.IsTransitionAllowed(ContractPhase.DangSoanThao, ContractPhase.DangGopY,
+                [AppRoles.Drafter], Guid.NewGuid())
+            .Should().BeFalse();
+    }
+}
diff --git a/tests/SolutionErp.Domain.Tests/PurchaseEvaluations/PurchaseEvaluationPolicyTests.cs b/tests/SolutionErp.Domain.Tests/PurchaseEvaluations/PurchaseEvaluationPolicyTests.cs
new file mode 100644
index 0000000..17e36e1
--- /dev/null
+++ b/tests/SolutionErp.Domain.Tests/PurchaseEvaluations/PurchaseEvaluationPolicyTests.cs
@@ -0,0 +1,180 @@
+using SolutionErp.Domain.Contracts;   // WorkflowApproverKind reuse
+using SolutionErp.Domain.Identity;
+using SolutionErp.Domain.PurchaseEvaluations;
+
+namespace SolutionErp.Domain.Tests.PurchaseEvaluations;
+
+// Tests cho PurchaseEvaluationPolicy — 2 quy trình A/B chính.
+// Mục tiêu: chống regression khi PEPhase thêm phase mới hoặc role mapping bị edit.
+
+public class PurchaseEvaluationPolicyTests
+{
+    // ===== A — DuyetNcc (NccOnly): 3-step (Drafter → Purchasing → CCM → CEO) =====
+
+    [Fact]
+    public void NccOnly_Drafter_DangSoanThao_To_ChoPurchasing_Allowed()
+    {
+        PurchaseEvaluationPolicies.NccOnly
+            .IsTransitionAllowed(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.ChoPurchasing,
+                [AppRoles.Drafter])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void NccOnly_Procurement_ChoPurchasing_To_ChoCCM_Allowed()
+    {
+        PurchaseEvaluationPolicies.NccOnly
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.ChoCCM,
+                [AppRoles.Procurement])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void NccOnly_CostControl_ChoCCM_GoesDirectlyTo_ChoCEODuyetNCC()
+    {
+        // A skip ChoDuAn + ChoCEODuyetPA — CCM đẩy thẳng CEO duyệt NCC
+        PurchaseEvaluationPolicies.NccOnly
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.ChoCEODuyetNCC,
+                [AppRoles.CostControl])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void NccOnly_DoesNotHave_ChoDuAn_Phase()
+    {
+        PurchaseEvaluationPolicies.NccOnly.HasPhase(PurchaseEvaluationPhase.ChoDuAn)
+            .Should().BeFalse("Quy trình A chỉ áp dụng khi không cần Dự án duyệt");
+    }
+
+    [Fact]
+    public void NccOnly_DoesNotHave_ChoCEODuyetPA_Phase()
+    {
+        PurchaseEvaluationPolicies.NccOnly.HasPhase(PurchaseEvaluationPhase.ChoCEODuyetPA)
+            .Should().BeFalse();
+    }
+
+    [Fact]
+    public void NccOnly_Director_FinalApproval_To_DaDuyet()
+    {
+        PurchaseEvaluationPolicies.NccOnly
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.DaDuyet,
+                [AppRoles.Director])
+            .Should().BeTrue();
+
+        PurchaseEvaluationPolicies.NccOnly
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoCEODuyetNCC, PurchaseEvaluationPhase.DaDuyet,
+                [AppRoles.AuthorizedSigner])
+            .Should().BeTrue();
+    }
+
+    // ===== B — DuyetNccPhuongAn (NccWithPlan): 5-step =====
+
+    [Fact]
+    public void NccWithPlan_Has_ChoDuAn_AndChoCEODuyetPA_Phases()
+    {
+        PurchaseEvaluationPolicies.NccWithPlan.HasPhase(PurchaseEvaluationPhase.ChoDuAn)
+            .Should().BeTrue();
+        PurchaseEvaluationPolicies.NccWithPlan.HasPhase(PurchaseEvaluationPhase.ChoCEODuyetPA)
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void NccWithPlan_Procurement_ChoPurchasing_GoesTo_ChoDuAn_NotChoCCM()
+    {
+        // Khác với A — B đi qua Dự án trước CCM
+        PurchaseEvaluationPolicies.NccWithPlan
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.ChoDuAn,
+                [AppRoles.Procurement])
+            .Should().BeTrue();
+
+        PurchaseEvaluationPolicies.NccWithPlan
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoPurchasing, PurchaseEvaluationPhase.ChoCCM,
+                [AppRoles.Procurement])
+            .Should().BeFalse();
+    }
+
+    [Fact]
+    public void NccWithPlan_ProjectManager_ChoDuAn_To_ChoCCM_Allowed()
+    {
+        PurchaseEvaluationPolicies.NccWithPlan
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoDuAn, PurchaseEvaluationPhase.ChoCCM,
+                [AppRoles.ProjectManager])
+            .Should().BeTrue();
+    }
+
+    [Fact]
+    public void NccWithPlan_CostControl_ChoCCM_GoesTo_ChoCEODuyetPA_NotDuyetNCC()
+    {
+        // B: CCM xong đi qua CEO duyệt PA trước, sau mới CEO duyệt NCC
+        PurchaseEvaluationPolicies.NccWithPlan
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.ChoCEODuyetPA,
+                [AppRoles.CostControl])
+            .Should().BeTrue();
+
+        PurchaseEvaluationPolicies.NccWithPlan
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.ChoCEODuyetNCC,
+                [AppRoles.CostControl])
+            .Should().BeFalse("CCM trong quy trình B không được skip CEO duyệt PA");
+    }
+
+    [Fact]
+    public void NccWithPlan_Director_ChoCEODuyetPA_To_ChoCEODuyetNCC()
+    {
+        PurchaseEvaluationPolicies.NccWithPlan
+            .IsTransitionAllowed(PurchaseEvaluationPhase.ChoCEODuyetPA, PurchaseEvaluationPhase.ChoCEODuyetNCC,
+                [AppRoles.Director])
+            .Should().BeTrue();
+    }
+
+    // ===== Reject paths chung cả 2 quy trình =====
+
+    [Theory]
+    [InlineData(nameof(PurchaseEvaluationPolicies.NccOnly))]
+    [InlineData(nameof(PurchaseEvaluationPolicies.NccWithPlan))]
+    public void BothPolicies_RejectFromCCM_GoesBackTo_DangSoanThao(string policyName)
+    {
+        var policy = policyName == nameof(PurchaseEvaluationPolicies.NccOnly)
+            ? PurchaseEvaluationPolicies.NccOnly
+            : PurchaseEvaluationPolicies.NccWithPlan;
+
+        policy.IsTransitionAllowed(PurchaseEvaluationPhase.ChoCCM, PurchaseEvaluationPhase.DangSoanThao,
+                [AppRoles.CostControl])
+            .Should().BeTrue();
+    }
+
+    [Theory]
+    [InlineData(nameof(PurchaseEvaluationPolicies.NccOnly))]
+    [InlineData(nameof(PurchaseEvaluationPolicies.NccWithPlan))]
+    public void BothPolicies_DangSoanThao_To_TuChoi_DrafterOrDeptManager(string policyName)
+    {
+        var policy = policyName == nameof(PurchaseEvaluationPolicies.NccOnly)
+            ? PurchaseEvaluationPolicies.NccOnly
+            : PurchaseEvaluationPolicies.NccWithPlan;
+
+        policy.IsTransitionAllowed(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.TuChoi,
+                [AppRoles.Drafter])
+            .Should().BeTrue();
+        policy.IsTransitionAllowed(PurchaseEvaluationPhase.DangSoanThao, PurchaseEvaluationPhase.TuChoi,
+                [AppRoles.Procurement])
+            .Should().BeFalse();
+    }
+
+    // ===== Registry mapping per PEType =====
+
+    [Theory]
+    [InlineData(PurchaseEvaluationType.DuyetNcc, "NccOnly")]
+    [InlineData(PurchaseEvaluationType.DuyetNccPhuongAn, "NccWithPlan")]
+    public void Registry_DefaultPolicyName_MapsCorrectly(
+        PurchaseEvaluationType type, string expectedName)
+    {
+        PurchaseEvaluationPolicyRegistry.DefaultPolicyNameFor(type)
+            .Should().Be(expectedName);
+    }
+
+    [Fact]
+    public void Registry_For_TypeA_ReturnsNccOnlyPolicy()
+    {
+        PurchaseEvaluationPolicyRegistry.For(PurchaseEvaluationType.DuyetNcc).Name
+            .Should().Be("NccOnly");
+    }
+}
diff --git a/tests/SolutionErp.Domain.Tests/SolutionErp.Domain.Tests.csproj b/tests/SolutionErp.Domain.Tests/SolutionErp.Domain.Tests.csproj
new file mode 100644
index 0000000..7520290
--- /dev/null
+++ b/tests/SolutionErp.Domain.Tests/SolutionErp.Domain.Tests.csproj
@@ -0,0 +1,28 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="coverlet.collector" Version="6.0.4" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
+    <PackageReference Include="xunit" Version="2.9.3" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.4" />
+    <!-- FluentAssertions 7.x — pin trước version 8 vì v8 yêu cầu commercial license. -->
+    <PackageReference Include="FluentAssertions" Version="7.2.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\Backend\SolutionErp.Domain\SolutionErp.Domain.csproj" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Using Include="Xunit" />
+    <Using Include="FluentAssertions" />
+  </ItemGroup>
+
+</Project>