[CLAUDE] PurchaseEvaluation: luy ke TAM TINH vs CHINH XAC — ComputePendingAsync + 5-field DTO + FE 2-app sub-dong amber/banner man duyet + D4 audit-note (UAT anh Kiet 15-07, 0 mig, test 520→528)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/SolutionErp.Infrastructure.Tests/Services/PePendingAccumulationTests.cs

@@ -0,0 +1,497 @@
+using Microsoft.AspNetCore.Identity;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using SolutionErp.Application.PurchaseEvaluations;         // PeBudgetAccumulator, ComputeAsync/ComputePendingAsync, GetPurchaseEvaluationQuery
+using SolutionErp.Application.PurchaseEvaluations.Dtos;    // PePendingPriorPeDto
+using SolutionErp.Domain.ApprovalWorkflowsV2;
+using SolutionErp.Domain.Contracts;                        // ApprovalDecision, ChangelogAction
+using SolutionErp.Domain.Identity;                         // AppRoles
+using SolutionErp.Domain.Master;
+using SolutionErp.Domain.Master.Catalogs;
+using SolutionErp.Domain.PurchaseEvaluations;
+using SolutionErp.Infrastructure.Services;
+using SolutionErp.Infrastructure.Tests.Common;
+
+namespace SolutionErp.Infrastructure.Tests.Services;
+
+// ===== S134 (2026-07-17) TEST-C — PE lũy kế TẠM TÍNH (PeBudgetAccumulator.ComputePendingAsync) =====
+// Code BE ĐÃ LAND (INV-2): lũy kế "phiếu TRƯỚC cùng cặp (ProjectId, WorkItemId) CHƯA duyệt xong"
+// BỔ SUNG (KHÔNG thay) số CHÍNH XÁC ComputeAsync (S133). 3 tầng cần phủ:
+//   (1) PeBudgetAccumulator.ComputePendingAsync — window Y HỆT ComputeAsync (peers cùng cặp,
+//       Id != peId, CreatedAt < peCreatedAt). 3 nhóm số:
+//         PendingSubmitted = Phase ∉ {DangSoanThao=1, DaDuyet=7, ChoDuyet=10, TuChoi=99} (= TraLai=98
+//                            + legacy 2-6) → Count + SUM(BudgetPeriodAmount ?? 0). ChoDuyet/DaDuyet
+//                            ĐÃ nằm trong ComputeAsync PrevSubmitted → loại tránh double-count.
+//         PendingSelected  = Phase ∉ {DangSoanThao, DaDuyet, TuChoi} && Suppliers.Any(IsWinner)
+//                            (GỒM ChoDuyet-có-winner = gap chính đề bài) → Count + SUM(ThanhTien IsSelected).
+//         PriorPes         = Phase ∉ {DaDuyet, TuChoi} orderby CreatedAt → PePendingPriorPeDto(Id, MaPhieu, (int)Phase).
+//   (2) GetPurchaseEvaluationQuery: nhánh live fill 5 field / nhánh frozen (DaDuyet + SnapshotAt) defaults 0/null.
+//   (3) D4 ApplyBudgetSnapshotOnFinalizeAsync: finalize khi còn phiếu trước chưa duyệt → +1 Changelog audit.
+//
+// Test theo CODE (S34 single source of truth). TEST-AFTER (code đã land, build 0/0). KHÔNG touch
+// production (src/Backend, fe-*). Mirror seed-helper PeBudgetFreezeTests :277-336 (CreatedAt override
+// thủ công — TestApplicationDbContext KHÔNG wire audit interceptor).
+public class PePendingAccumulationTests
+{
+    // Giá chốt hợp lệ khi finalize (ApplyApprovedPriceOnFinalize đòi source ∈ ValidApprovedPriceSources).
+    private const decimal ValidApprovedPrice = 400_000_000m;
+    private const string ValidApprovedSource = "Ncc";
+
+    // Mốc thời gian: peers seed TRƯỚC (BaseT.AddDays(-n)); "phiếu đang xét" = CurCreatedAt (muộn hơn).
+    private static readonly DateTime BaseT = new(2026, 7, 17, 8, 0, 0, DateTimeKind.Utc);
+    private static readonly DateTime CurCreatedAt = new(2026, 7, 17, 12, 0, 0, DateTimeKind.Utc);
+
+    private static (PurchaseEvaluationWorkflowService svc, IdentityFixture fix,
+        TestApplicationDbContext db) CreateService()
+    {
+        var fix = new IdentityFixture();
+        var db = fix.Services.GetRequiredService<TestApplicationDbContext>();
+        var um = fix.Services.GetRequiredService<UserManager<User>>();
+        var clock = new FixedDateTime(new DateTime(2026, 7, 17, 0, 0, 0, DateTimeKind.Utc));
+        var notify = new NoOpNotificationService();
+        var svc = new PurchaseEvaluationWorkflowService(db, clock, notify, um);
+        return (svc, fix, db);
+    }
+
+    // ---- shared seed helpers (mirror PeBudgetFreezeTests) ----
+
+    private static async Task<(Project project, WorkItem wi)> SeedProjectAndWorkItemAsync(
+        TestApplicationDbContext db, string suffix)
+    {
+        var project = new Project { Id = Guid.NewGuid(), Code = "PRJ-PA-" + suffix, Name = "Dự án " + suffix };
+        var wi = new WorkItem { Id = Guid.NewGuid(), Code = "WI-PA-" + suffix, Name = "Hạng mục " + suffix, IsActive = true };
+        db.Projects.Add(project);
+        db.WorkItems.Add(wi);
+        await db.SaveChangesAsync(CancellationToken.None);
+        return (project, wi);
+    }
+
+    // 1 record PeWorkItemBudget per cặp (ProjectId × WorkItemId). NAMING: Initial/Adjustment = CCM.
+    private static async Task SeedPairAsync(
+        TestApplicationDbContext db, Guid projectId, Guid wiId, decimal? ccmInit)
+    {
+        db.PeWorkItemBudgets.Add(new PeWorkItemBudget
+        {
+            Id = Guid.NewGuid(),
+            ProjectId = projectId,
+            WorkItemId = wiId,
+            InitialAmount = ccmInit,
+        });
+        await db.SaveChangesAsync(CancellationToken.None);
+    }
+
+    // Seed 1 đơn vị IsWinner + 1 detail + 1 quote IsSelected cho phiếu (own quotes → winnerQuoteTotal).
+    private static async Task SeedWinnerQuoteAsync(
+        TestApplicationDbContext db, PurchaseEvaluation pe, decimal thanhTien)
+    {
+        var pes = new PurchaseEvaluationSupplier
+        {
+            Id = Guid.NewGuid(),
+            PurchaseEvaluationId = pe.Id,
+            SupplierId = Guid.NewGuid(),
+            Order = 0,
+            IsWinner = true,
+        };
+        var detail = new PurchaseEvaluationDetail
+        {
+            Id = Guid.NewGuid(),
+            PurchaseEvaluationId = pe.Id,
+            GroupCode = "A.I",
+            GroupName = "Bê tông",
+            NoiDung = "Concrete",
+            Order = 0,
+        };
+        db.PurchaseEvaluationSuppliers.Add(pes);
+        db.PurchaseEvaluationDetails.Add(detail);
+        db.PurchaseEvaluationQuotes.Add(new PurchaseEvaluationQuote
+        {
+            Id = Guid.NewGuid(),
+            PurchaseEvaluationDetailId = detail.Id,
+            PurchaseEvaluationSupplierId = pes.Id,
+            ThanhTien = thanhTien,
+            IsSelected = true,
+        });
+        await db.SaveChangesAsync(CancellationToken.None);
+    }
+
+    // Peer PE cùng cặp cho accumulator (lũy kế phiếu TRƯỚC). CreatedAt override thủ công.
+    private static async Task<PurchaseEvaluation> SeedPeerAsync(
+        TestApplicationDbContext db, Guid projectId, Guid wiId,
+        PurchaseEvaluationPhase phase, decimal? budgetPeriod, DateTime createdAt,
+        decimal? winnerQuote, string code)
+    {
+        var peer = new PurchaseEvaluation
+        {
+            Id = Guid.NewGuid(),
+            Type = PurchaseEvaluationType.DuyetNcc,
+            Phase = phase,
+            MaPhieu = code,
+            TenGoiThau = "Peer " + code,
+            ProjectId = projectId,
+            WorkItemId = wiId,
+            DrafterUserId = Guid.NewGuid(),
+            BudgetPeriodAmount = budgetPeriod,
+        };
+        db.PurchaseEvaluations.Add(peer);
+        await db.SaveChangesAsync(CancellationToken.None);
+        peer.CreatedAt = createdAt;   // accumulator dùng CreatedAt < peCreatedAt
+        await db.SaveChangesAsync(CancellationToken.None);
+        if (winnerQuote is decimal wq)
+            await SeedWinnerQuoteAsync(db, peer, wq);
+        return peer;
+    }
+
+    // Workflow V2 1 Bước 1 Cấp AllowApproverFinalize=true → duyệt slot cuối = DaDuyet (finalize-branch).
+    private static async Task<ApprovalWorkflow> SeedFinalizeWorkflowAsync(
+        TestApplicationDbContext db, Guid approverUserId, string code)
+    {
+        var wf = new ApprovalWorkflow
+        {
+            Code = code,
+            Version = 1,
+            ApplicableType = ApprovalWorkflowApplicableType.DuyetNcc,
+            Name = "QT test pending-accumulation",
+            IsActive = true,
+            IsUserSelectable = true,
+        };
+        var step = new ApprovalWorkflowStep { ApprovalWorkflowId = wf.Id, Order = 1, Name = "Bước 1" };
+        step.Levels.Add(new ApprovalWorkflowLevel
+        {
+            ApprovalWorkflowStepId = step.Id,
+            Order = 1,
+            Name = "Cấp 1",
+            ApproverUserId = approverUserId,
+            AllowApproverFinalize = true,
+        });
+        wf.Steps.Add(step);
+        db.ApprovalWorkflows.Add(wf);
+        await db.SaveChangesAsync(CancellationToken.None);
+        return wf;
+    }
+
+    // PE đứng tại slot duyệt cuối V2 (ChoDuyet) gắn cặp + workflow đã pin.
+    private static PurchaseEvaluation BuildPeAtFinalizeSlot(
+        Guid approvalWorkflowId, Guid projectId, Guid? workItemId, Guid drafterUserId, string code)
+        => new()
+        {
+            Id = Guid.NewGuid(),
+            Type = PurchaseEvaluationType.DuyetNcc,
+            Phase = PurchaseEvaluationPhase.ChoDuyet,
+            MaPhieu = code,
+            TenGoiThau = "Gói thầu " + code,
+            ProjectId = projectId,
+            WorkItemId = workItemId,
+            DrafterUserId = drafterUserId,
+            ApprovalWorkflowId = approvalWorkflowId,
+            CurrentWorkflowStepIndex = 0,
+            CurrentApprovalLevelOrder = 1,
+            SlaDeadline = new DateTime(2026, 7, 24, 0, 0, 0, DateTimeKind.Utc),
+        };
+
+    // Approve-in-place + giá chốt hợp lệ → DaDuyet qua finalize path.
+    private static Task ApproveWithPriceAsync(
+        PurchaseEvaluationWorkflowService svc, PurchaseEvaluation pe, Guid approver, string[] roles) =>
+        svc.TransitionAsync(
+            evaluation: pe,
+            targetPhase: PurchaseEvaluationPhase.ChoDuyet,
+            actorUserId: approver,
+            actorRoles: roles,
+            decision: ApprovalDecision.Approve,
+            comment: null,
+            approvedPriceAmount: ValidApprovedPrice,
+            approvedPriceSource: ValidApprovedSource,
+            ct: CancellationToken.None);
+
+    // Direct call convenience — curPeId synthetic (KHÔNG cần row phiếu đang xét; accumulator chỉ
+    // filter p.Id != peId && p.CreatedAt < peCreatedAt). Window = CurCreatedAt (muộn hơn mọi peer sớm).
+    private static Task<PePendingAccumulation> ComputePendingAsync(
+        TestApplicationDbContext db, Guid projectId, Guid wiId) =>
+        PeBudgetAccumulator.ComputePendingAsync(db, projectId, wiId, Guid.NewGuid(), CurCreatedAt, CancellationToken.None);
+
+    // =====================================================================
+    // C1 — peer ChoDuyet + IsWinner + quote IsSelected → PendingSelected (gap chính đề bài):
+    //   Total = SUM ThanhTien, Count = 1; peer CÓ MẶT trong PriorPes (đúng Id + MaPhieu + Phase=10).
+    //   PendingSubmitted = 0 (ChoDuyet CỐ Ý loại — đã nằm ComputeAsync PrevSubmitted, tránh double-count).
+    // =====================================================================
+    [Fact]
+    public async Task ChoDuyetWinner_CountsInPendingSelected_AndListedInPriorPes()
+    {
+        var (_, fix, db) = CreateService();
+        using (fix)
+        {
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C1");
+            var peer = await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: 30_000_000m, createdAt: BaseT.AddDays(-2), winnerQuote: 70_000_000m, code: "PE-C1-CD");
+
+            var r = await ComputePendingAsync(db, project.Id, wi.Id);
+
+            r.PendingSelectedTotal.Should().Be(70_000_000m, "peer ChoDuyet + winner + quote IsSelected → tạm tính đã chọn");
+            r.PendingSelectedCount.Should().Be(1);
+            r.PendingSubmittedTotal.Should().Be(0m, "ChoDuyet loại khỏi PendingSubmitted (đã nằm ComputeAsync PrevSubmitted)");
+            r.PendingSubmittedCount.Should().Be(0);
+
+            r.PriorPes.Should().ContainSingle("ChoDuyet ∉ {DaDuyet, TuChoi} → có trong danh sách cần lưu ý");
+            var prior = r.PriorPes.Single();
+            prior.Id.Should().Be(peer.Id);
+            prior.MaPhieu.Should().Be("PE-C1-CD");
+            prior.Phase.Should().Be(10, "Phase = (int)ChoDuyet");
+        }
+    }
+
+    // =====================================================================
+    // C2 — peer TuChoi → mọi delta 0 + KHÔNG trong PriorPes; peer DaDuyet → delta 0 (nằm bên
+    //   ComputeAsync chính xác, KHÔNG lũy kế tạm tính) + KHÔNG trong PriorPes.
+    // =====================================================================
+    [Fact]
+    public async Task TuChoiAndDaDuyetPeers_ContributeNothingToPending_AndAbsentFromPriorPes()
+    {
+        var (_, fix, db) = CreateService();
+        using (fix)
+        {
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C2");
+            // Cả 2 peer đều có winner + budget để CHỨNG MINH exclusion theo Phase (không phải thiếu data).
+            await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.TuChoi,
+                budgetPeriod: 50_000_000m, createdAt: BaseT.AddDays(-3), winnerQuote: 30_000_000m, code: "PE-C2-REJ");
+            await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.DaDuyet,
+                budgetPeriod: 100_000_000m, createdAt: BaseT.AddDays(-2), winnerQuote: 90_000_000m, code: "PE-C2-DD");
+
+            var r = await ComputePendingAsync(db, project.Id, wi.Id);
+
+            r.PendingSubmittedTotal.Should().Be(0m, "TuChoi + DaDuyet đều bị loại khỏi PendingSubmitted");
+            r.PendingSubmittedCount.Should().Be(0);
+            r.PendingSelectedTotal.Should().Be(0m, "TuChoi + DaDuyet đều bị loại khỏi PendingSelected dù có winner");
+            r.PendingSelectedCount.Should().Be(0);
+            r.PriorPes.Should().BeEmpty("cả 2 phase = terminal → không nằm danh sách cần lưu ý");
+        }
+    }
+
+    // =====================================================================
+    // C3 — peer DangSoanThao (Nháp) → TRONG PriorPes NHƯNG delta tiền = 0 (D1 list-only); peer TraLai
+    //   có BudgetPeriodAmount → PendingSubmittedTotal đúng (D2). Chứng minh: budget 40tr của Nháp
+    //   KHÔNG cộng, budget 60tr của TraLai CÓ cộng.
+    // =====================================================================
+    [Fact]
+    public async Task DraftPeer_ListOnly_TraLaiPeer_CountsInPendingSubmitted()
+    {
+        var (_, fix, db) = CreateService();
+        using (fix)
+        {
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C3");
+            var draft = await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.DangSoanThao,
+                budgetPeriod: 40_000_000m, createdAt: BaseT.AddDays(-3), winnerQuote: null, code: "PE-C3-NHAP");
+            var traLai = await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.TraLai,
+                budgetPeriod: 60_000_000m, createdAt: BaseT.AddDays(-2), winnerQuote: null, code: "PE-C3-TRALAI");
+
+            var r = await ComputePendingAsync(db, project.Id, wi.Id);
+
+            r.PendingSubmittedTotal.Should().Be(60_000_000m, "chỉ TraLai cộng (D2); Nháp 40tr là list-only (D1)");
+            r.PendingSubmittedCount.Should().Be(1, "chỉ TraLai; DangSoanThao loại khỏi PendingSubmitted");
+            r.PendingSelectedTotal.Should().Be(0m, "không peer nào có winner");
+            r.PendingSelectedCount.Should().Be(0);
+
+            r.PriorPes.Should().HaveCount(2, "Nháp + TraLai đều ∉ {DaDuyet, TuChoi}");
+            r.PriorPes.Select(p => p.Id).Should().ContainInOrder(new[] { draft.Id, traLai.Id }, "orderby CreatedAt");
+            r.PriorPes.Should().Contain(p => p.Id == draft.Id && p.Phase == 1,
+                "peer Nháp CÓ trong danh sách (list-only) dù đóng góp tiền = 0");
+        }
+    }
+
+    // =====================================================================
+    // C4 — peer-window: peer CreatedAt > phiếu đang xét → loại HOÀN TOÀN (mirror PeBudgetFreezeTests
+    //   :435-451). Contrast: peer TRƯỚC vẫn lọt để chứng minh filter phân biệt đúng chiều.
+    // =====================================================================
+    [Fact]
+    public async Task PeerCreatedAfterCurrent_ExcludedFromWindow()
+    {
+        var (_, fix, db) = CreateService();
+        using (fix)
+        {
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C4");
+            // (a) peer TRƯỚC CurCreatedAt (noon) → LỌT.
+            var before = await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: 10_000_000m, createdAt: BaseT.AddDays(-1), winnerQuote: 25_000_000m, code: "PE-C4-BEFORE");
+            // (b) peer SAU CurCreatedAt → LOẠI hoàn toàn.
+            var after = await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: 999_000_000m, createdAt: CurCreatedAt.AddHours(1), winnerQuote: 999_000_000m, code: "PE-C4-AFTER");
+
+            var r = await ComputePendingAsync(db, project.Id, wi.Id);
+
+            r.PendingSelectedTotal.Should().Be(25_000_000m, "chỉ peer TRƯỚC lọt; peer SAU (999tr) bị loại khỏi window");
+            r.PendingSelectedCount.Should().Be(1);
+            r.PriorPes.Should().ContainSingle().Which.Id.Should().Be(before.Id);
+            r.PriorPes.Should().NotContain(p => p.Id == after.Id, "peer CreatedAt > current → ngoài window");
+        }
+    }
+
+    // =====================================================================
+    // C5 — quote ÂM trong PendingSelected (signed-sum): peer ChoDuyet + winner + quote −500k →
+    //   PendingSelectedTotal = −500k (báo giá âm = phát-sinh-giảm/hoàn NCC, KHÔNG clamp).
+    // =====================================================================
+    [Fact]
+    public async Task NegativeSelectedQuote_ProducesSignedPendingSelectedTotal()
+    {
+        var (_, fix, db) = CreateService();
+        using (fix)
+        {
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C5");
+            await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: null, createdAt: BaseT.AddDays(-1), winnerQuote: -500_000m, code: "PE-C5-NEG");
+
+            var r = await ComputePendingAsync(db, project.Id, wi.Id);
+
+            r.PendingSelectedTotal.Should().Be(-500_000m, "signed-sum: quote âm giữ dấu, KHÔNG clamp về 0");
+            r.PendingSelectedCount.Should().Be(1);
+        }
+    }
+
+    // =====================================================================
+    // C6 REGRESSION chính-xác bất động: cùng seed {DaDuyet+winner, ChoDuyet+winner}, gọi CẢ
+    //   ComputeAsync (S133 số CHÍNH XÁC) và ComputePendingAsync (S134 tạm tính) — chứng minh 2 hàm
+    //   BỔ SUNG nhau, KHÔNG chồng lấn:
+    //     ComputeAsync.PrevSelected  = CHỈ DaDuyet+winner (thêm peer ChoDuyet KHÔNG đổi).
+    //     ComputeAsync.PrevSubmitted = ChoDuyet + DaDuyet (như cũ).
+    //     ComputePendingAsync.PendingSelected  = CHỈ ChoDuyet+winner (DaDuyet loại).
+    //     ComputePendingAsync.PendingSubmitted = 0 (ChoDuyet + DaDuyet đều loại khỏi tạm tính).
+    // =====================================================================
+    [Fact]
+    public async Task Compute_And_ComputePending_AreComplementary_NoDoubleCount()
+    {
+        var (_, fix, db) = CreateService();
+        using (fix)
+        {
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C6");
+            await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.DaDuyet,
+                budgetPeriod: 100_000_000m, createdAt: BaseT.AddDays(-3), winnerQuote: 90_000_000m, code: "PE-C6-DD");
+            await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: 30_000_000m, createdAt: BaseT.AddDays(-2), winnerQuote: 50_000_000m, code: "PE-C6-CD");
+
+            var curPeId = Guid.NewGuid();
+            var exact = await PeBudgetAccumulator.ComputeAsync(
+                db, project.Id, wi.Id, curPeId, CurCreatedAt, Array.Empty<Guid>(), CancellationToken.None);
+            var pending = await PeBudgetAccumulator.ComputePendingAsync(
+                db, project.Id, wi.Id, curPeId, CurCreatedAt, CancellationToken.None);
+
+            // ComputeAsync (S133) — số CHÍNH XÁC KHÔNG bị peer ChoBudget kéo lệch.
+            exact.PrevSelectedTotal.Should().Be(90_000_000m, "PrevSelected CHỈ đếm DaDuyet+winner");
+            exact.PrevSelectedCount.Should().Be(1, "peer ChoDuyet KHÔNG cộng vào PrevSelected (bất động)");
+            exact.PrevSubmittedTotal.Should().Be(130_000_000m, "PrevSubmitted = ChoDuyet 30tr + DaDuyet 100tr (như cũ)");
+            exact.PrevSubmittedCount.Should().Be(2);
+
+            // ComputePendingAsync (S134) — bổ sung ChoDuyet winner, KHÔNG chồng DaDuyet.
+            pending.PendingSelectedTotal.Should().Be(50_000_000m, "PendingSelected CHỈ ChoDuyet+winner (DaDuyet loại)");
+            pending.PendingSelectedCount.Should().Be(1);
+            pending.PendingSubmittedTotal.Should().Be(0m, "ChoDuyet + DaDuyet đều loại khỏi PendingSubmitted (no double-count)");
+            pending.PendingSubmittedCount.Should().Be(0);
+            pending.PriorPes.Should().ContainSingle("chỉ ChoDuyet ∉ {DaDuyet, TuChoi}");
+        }
+    }
+
+    // =====================================================================
+    // C7 — DISPLAY frozen: phiếu DaDuyet (finalize) + SnapshotAt qua GetPurchaseEvaluationQuery →
+    //   DTO pending 4 số = 0 + PendingPriorPes null, DÙ tồn tại peer ChoDuyet cùng cặp (nhánh frozen
+    //   hardcode defaults, KHÔNG chạy accumulator). Mirror T7 PeBudgetFreezeTests :730.
+    // =====================================================================
+    [Fact]
+    public async Task FrozenQuery_ReturnsZeroPendingAndNullPriorPes_EvenWithPendingPeer()
+    {
+        var (svc, fix, db) = CreateService();
+        using (fix)
+        {
+            var um = fix.Services.GetRequiredService<UserManager<User>>();
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C7");
+            await SeedPairAsync(db, project.Id, wi.Id, 200_000_000m);
+
+            // Peer ChoDuyet + winner cùng cặp, TRƯỚC phiếu B → nếu B ở nhánh LIVE sẽ có pending != 0.
+            await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: 50_000_000m, createdAt: BaseT.AddDays(-2), winnerQuote: 80_000_000m, code: "PE-C7-PEER");
+
+            var approver = (await fix.CreateUserAsync("appr@c7.test", "Approver", null, Array.Empty<string>())).Id;
+            var wf = await SeedFinalizeWorkflowAsync(db, approver, "QT-PA-C7");
+            var pe = BuildPeAtFinalizeSlot(wf.Id, project.Id, wi.Id, Guid.NewGuid(), "PE-C7-B");
+            db.PurchaseEvaluations.Add(pe);
+            await db.SaveChangesAsync(CancellationToken.None);
+            pe.CreatedAt = BaseT;   // muộn hơn peer → peer lọt window (nếu live)
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await ApproveWithPriceAsync(svc, pe, approver, Array.Empty<string>());
+            pe.Phase.Should().Be(PurchaseEvaluationPhase.DaDuyet);
+
+            var admin = new TestCurrentUser(Guid.NewGuid(), "Admin", null, AppRoles.Admin);
+            var bundle = await new GetPurchaseEvaluationQueryHandler(db, um, admin)
+                .Handle(new GetPurchaseEvaluationQuery(pe.Id), CancellationToken.None);
+            var s = bundle.BudgetSummary!;
+
+            s.BudgetFrozen.Should().BeTrue("phiếu DaDuyet + SnapshotAt → nhánh frozen (test không vacuous)");
+            s.PendingSubmittedTotal.Should().Be(0m, "nhánh frozen hardcode 0 dù tồn tại peer ChoDuyet");
+            s.PendingSubmittedCount.Should().Be(0);
+            s.PendingSelectedTotal.Should().Be(0m, "nhánh frozen KHÔNG chạy accumulator tạm tính");
+            s.PendingSelectedCount.Should().Be(0);
+            s.PendingPriorPes.Should().BeNull("nhánh frozen serve PendingPriorPes null");
+        }
+    }
+
+    // =====================================================================
+    // C8 — D4 audit: finalize phiếu B tới DaDuyet QUA TransitionAsync (finalize path) khi TỒN TẠI
+    //   peer A ChoDuyet cùng cặp → +1 Changelog Action=Update, EntityType=Workflow, UserId=null,
+    //   UserName="Hệ thống", ContextNote chứa "[S134 pending-prior]" + MaPhieu A (filter discriminator
+    //   ContextNote.Contains — #48 tie-break tránh row Transition). CONTRAST: finalize phiếu KHÔNG có
+    //   pending peer → 0 row loại này.
+    // =====================================================================
+    [Fact]
+    public async Task Finalize_WithPendingPriorPeer_WritesAuditChangelog_ContrastNoPeerWritesNone()
+    {
+        var (svc, fix, db) = CreateService();
+        using (fix)
+        {
+            // ---- Case chính: có peer A ChoDuyet trước phiếu B ----
+            var (project, wi) = await SeedProjectAndWorkItemAsync(db, "C8");
+            var peerA = await SeedPeerAsync(db, project.Id, wi.Id, PurchaseEvaluationPhase.ChoDuyet,
+                budgetPeriod: 50_000_000m, createdAt: BaseT.AddDays(-2), winnerQuote: null, code: "PE-C8-A");
+
+            var approver = (await fix.CreateUserAsync("appr@c8.test", "Approver", null, Array.Empty<string>())).Id;
+            var wf = await SeedFinalizeWorkflowAsync(db, approver, "QT-PA-C8");
+            var peB = BuildPeAtFinalizeSlot(wf.Id, project.Id, wi.Id, Guid.NewGuid(), "PE-C8-B");
+            db.PurchaseEvaluations.Add(peB);
+            await db.SaveChangesAsync(CancellationToken.None);
+            peB.CreatedAt = BaseT;   // muộn hơn peer A → A lọt window pending
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await ApproveWithPriceAsync(svc, peB, approver, Array.Empty<string>());
+            peB.Phase.Should().Be(PurchaseEvaluationPhase.DaDuyet);
+
+            // Filter discriminator ContextNote.Contains (#48 tie-break) → cô lập row D4 khỏi row Transition.
+            var d4 = await db.PurchaseEvaluationChangelogs.AsNoTracking()
+                .Where(c => c.PurchaseEvaluationId == peB.Id
+                    && c.ContextNote != null && c.ContextNote.Contains("[S134 pending-prior]"))
+                .ToListAsync(CancellationToken.None);
+
+            d4.Should().ContainSingle("finalize khi còn 1 phiếu trước chưa duyệt → đúng 1 row audit D4");
+            var row = d4.Single();
+            row.Action.Should().Be(ChangelogAction.Update, "D4 = Update, KHÔNG Transition (gotcha #49 tránh 2 row chuyển phase)");
+            row.EntityType.Should().Be(PurchaseEvaluationEntityType.Workflow);
+            row.PhaseAtChange.Should().Be(PurchaseEvaluationPhase.DaDuyet);
+            row.UserId.Should().BeNull("D4 do hệ thống ghi");
+            row.UserName.Should().Be("Hệ thống");
+            row.ContextNote.Should().Contain(peerA.MaPhieu!, "audit liệt kê mã phiếu trước còn treo (peer A)");
+
+            // ---- CONTRAST: phiếu C cặp MỚI không peer → 0 row D4 ----
+            var (project2, wi2) = await SeedProjectAndWorkItemAsync(db, "C8none");
+            var approver2 = (await fix.CreateUserAsync("appr2@c8.test", "Approver2", null, Array.Empty<string>())).Id;
+            var wf2 = await SeedFinalizeWorkflowAsync(db, approver2, "QT-PA-C8b");
+            var peC = BuildPeAtFinalizeSlot(wf2.Id, project2.Id, wi2.Id, Guid.NewGuid(), "PE-C8-C");
+            db.PurchaseEvaluations.Add(peC);
+            await db.SaveChangesAsync(CancellationToken.None);
+            peC.CreatedAt = BaseT;
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await ApproveWithPriceAsync(svc, peC, approver2, Array.Empty<string>());
+            peC.Phase.Should().Be(PurchaseEvaluationPhase.DaDuyet);
+
+            var noneCount = await db.PurchaseEvaluationChangelogs.AsNoTracking()
+                .CountAsync(c => c.PurchaseEvaluationId == peC.Id
+                    && c.ContextNote != null && c.ContextNote.Contains("[S134 pending-prior]"),
+                    CancellationToken.None);
+            noneCount.Should().Be(0, "finalize không còn phiếu trước treo → KHÔNG ghi row D4");
+        }
+    }
+}