[CLAUDE] Workflow: wire ApproveV2 + LevelOpinions cho 4 WorkflowApps module (Phase 11 P11-A)

Wire full approval workflow V2 cho Leave/OT/Travel/Vehicle — cookie-cutter
mirror Proposal (Mig 38). Trước đây skeleton Phase 1 (Create+List), giờ
ApproveV2 advance-level + UPSERT LevelOpinion + atomic codegen.

Schema (Mig 41 WireWorkflowAppsApprovalV2 — 84→89 tables, pure additive):
- 4 bảng {Leave,Ot,Travel,Vehicle}LevelOpinions (UNIQUE composite + Cascade
  parent + Restrict Level — mirror ProposalLevelOpinion)
- 1 bảng WorkflowAppCodeSequences (shared atomic MaDonTu, Prefix-keyed)
- 4 cột RejectedFromStatus (smart return tracking)
- enum ApprovalWorkflowApplicableType.TravelRequest = 9

Application (LeaveOt + TravelVehicle ApprovalFeatures.cs — 30 handler):
- GetById detail (Include LevelOpinions + JOIN Step/Level) · UpdateDraft
- Submit (gen MaDonTu + DaGuiDuyet + level=1, verify ApplicableType per module)
- Approve (verify actor==ApproverUserId OR Admin, UPSERT opinion latest-write-wins,
  advance level OR terminal DaDuyet, empty comment → placeholder)
- Reject (→TuChoi) · Return (→TraLai + RejectedFromStatus)

Api: 4 controller +6 route mỗi cái (GET/{id}, PUT/{id}, submit/approve/reject/return)
Infra: DbInitializer seed 4 workflow V2 mẫu (QT-NP/OT/CT/XE-V2-001) → UAT test ngay
FE: WorkflowAppDetailPage.tsx declarative 4-kind (fe-admin+fe-user SHA256 identical)
  — workflow status + opinion timeline + action buttons; gỡ banner skeleton + row nav

Tests: +11 WorkflowAppApproveV2Tests (130→141 PASS) — state machine + UPSERT
  invariant + guards + codegen + forbidden + placeholder (Leave full + Ot smoke)

Verify: build 0 error · 141 test PASS · FE build ×2 · reviewer checklist
  (ApplicableType per-module + cross-module DbSet + [Authorize] — no copy-paste bug)
Known-minor (unreachable): Reject/Return actor-check skip nếu CurrentApprovalLevelOrder
  null — nhưng DaGuiDuyet luôn có set (defer hardening).
ItTicket KHÔNG đụng (kanban, no workflow V2).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/SolutionErp.Infrastructure.Tests/Application/WorkflowAppApproveV2Tests.cs

@@ -0,0 +1,443 @@
+using Microsoft.AspNetCore.Identity;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using SolutionErp.Application.Common.Exceptions;
+using SolutionErp.Application.Office;
+using SolutionErp.Domain.ApprovalWorkflowsV2;
+using SolutionErp.Domain.Identity;
+using SolutionErp.Domain.Office;
+using SolutionErp.Infrastructure.Tests.Common;
+
+namespace SolutionErp.Infrastructure.Tests.Application;
+
+// Phase 11 P11-A Wave 4 (S42 2026-05-30) — test-after ApproveV2 wire WorkflowApps.
+// Critical-algo state machine + UPSERT invariant cho LeaveOtApprovalFeatures.cs
+// (LeaveRequest đầy đủ 8 case + OtRequest smoke 1 case).
+//
+// Handlers là CQRS MediatR — inject IApplicationDbContext + ICurrentUser + IDateTime
+// trực tiếp (không qua service). Khác ContractWorkflowServiceApproveV2Tests (service
+// wire 6 dep) — đây nhẹ hơn, instantiate handler + gọi Handle().
+//
+// Mirror LeaveOtApprovalFeatures.cs:250 ApproveLeaveRequestHandler. Status state:
+//   Nhap=1, DaGuiDuyet=2, TraLai=3, TuChoi=4, DaDuyet=5.
+// LevelOpinion UNIQUE composite (LeaveRequestId, ApprovalWorkflowLevelId).
+public class WorkflowAppApproveV2Tests
+{
+    private static readonly DateTime FixedNow = new(2026, 5, 30, 8, 0, 0, DateTimeKind.Utc);
+
+    private static (IdentityFixture fix, TestApplicationDbContext db, FixedDateTime clock) NewCtx()
+    {
+        var fix = new IdentityFixture();
+        var db = fix.Services.GetRequiredService<TestApplicationDbContext>();
+        var clock = new FixedDateTime(FixedNow);
+        return (fix, db, clock);
+    }
+
+    private static TestCurrentUser AsUser(User u, params string[] roles)
+        => new() { UserId = u.Id, FullName = u.FullName, Roles = roles ?? Array.Empty<string>() };
+
+    // Seed 1 Bước × N Cấp LeaveRequest workflow. Trả về list Levels theo Order asc.
+    private static async Task<(ApprovalWorkflow wf, List<ApprovalWorkflowLevel> levels)> SeedLeaveWorkflowAsync(
+        TestApplicationDbContext db, params Guid[] approverUserIds)
+    {
+        var wf = new ApprovalWorkflow
+        {
+            Id = Guid.NewGuid(),
+            Code = "QT-LR-001",
+            Version = 1,
+            Name = "Quy trình nghỉ phép test",
+            ApplicableType = ApprovalWorkflowApplicableType.LeaveRequest,
+            IsActive = true,
+            IsUserSelectable = true,
+        };
+        var step = new ApprovalWorkflowStep
+        {
+            Id = Guid.NewGuid(),
+            ApprovalWorkflowId = wf.Id,
+            Order = 1,
+            DepartmentId = null,
+            Name = "Bước 1",
+        };
+        var levels = new List<ApprovalWorkflowLevel>();
+        for (var i = 0; i < approverUserIds.Length; i++)
+        {
+            levels.Add(new ApprovalWorkflowLevel
+            {
+                Id = Guid.NewGuid(),
+                ApprovalWorkflowStepId = step.Id,
+                Order = i + 1,
+                ApproverUserId = approverUserIds[i],
+            });
+        }
+        db.ApprovalWorkflows.Add(wf);
+        db.ApprovalWorkflowSteps.Add(step);
+        db.ApprovalWorkflowLevels.AddRange(levels);
+        await db.SaveChangesAsync(CancellationToken.None);
+        return (wf, levels);
+    }
+
+    private static LeaveRequest BuildLeave(
+        Guid requesterId,
+        Guid? workflowId,
+        WorkflowAppStatus status,
+        int? currentLevel)
+        => new()
+        {
+            Id = Guid.NewGuid(),
+            RequesterUserId = requesterId,
+            RequesterFullName = "Người tạo",
+            LeaveTypeId = Guid.NewGuid(),
+            StartDate = FixedNow.Date,
+            EndDate = FixedNow.Date.AddDays(2),
+            NumDays = 3,
+            Reason = "Nghỉ việc riêng",
+            Status = status,
+            ApprovalWorkflowId = workflowId,
+            CurrentApprovalLevelOrder = currentLevel,
+        };
+
+    // ============ Case 1: Submit happy path ============
+
+    [Fact]
+    public async Task Submit_FromNhap_AdvancesToDaGuiDuyet_GeneratesMaDonTu()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c1@test.local", "Requester", null, Array.Empty<string>());
+            var approver = await fix.CreateUserAsync("ap-c1@test.local", "Approver", null, Array.Empty<string>());
+            var (wf, _) = await SeedLeaveWorkflowAsync(db, approver.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.Nhap, currentLevel: null);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            var handler = new SubmitLeaveRequestHandler(db, AsUser(requester), clock);
+            await handler.Handle(new SubmitLeaveRequestCommand(leave.Id), CancellationToken.None);
+
+            leave.Status.Should().Be(WorkflowAppStatus.DaGuiDuyet);
+            leave.CurrentApprovalLevelOrder.Should().Be(1);
+            leave.RejectedFromStatus.Should().BeNull();
+            leave.MaDonTu.Should().NotBeNullOrEmpty();
+            leave.MaDonTu.Should().Be("DT/LR/2026/001", "prefix DT/LR + năm clock + seq D3");
+
+            var seq = await db.WorkflowAppCodeSequences.FirstAsync(s => s.Prefix == "DT/LR/2026");
+            seq.LastSeq.Should().Be(1);
+        }
+    }
+
+    // ============ Case 2: Submit guards ============
+
+    [Fact]
+    public async Task Submit_WhenStatusNotNhapOrTraLai_ThrowsConflict()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c2a@test.local", "Requester", null, Array.Empty<string>());
+            var approver = await fix.CreateUserAsync("ap-c2a@test.local", "Approver", null, Array.Empty<string>());
+            var (wf, _) = await SeedLeaveWorkflowAsync(db, approver.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            var handler = new SubmitLeaveRequestHandler(db, AsUser(requester), clock);
+            var act = async () => await handler.Handle(new SubmitLeaveRequestCommand(leave.Id), CancellationToken.None);
+
+            await act.Should().ThrowAsync<ConflictException>().WithMessage("*Nháp hoặc Trả lại*");
+        }
+    }
+
+    [Fact]
+    public async Task Submit_WhenApprovalWorkflowIdNull_ThrowsConflict()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c2b@test.local", "Requester", null, Array.Empty<string>());
+
+            var leave = BuildLeave(requester.Id, workflowId: null, WorkflowAppStatus.Nhap, currentLevel: null);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            var handler = new SubmitLeaveRequestHandler(db, AsUser(requester), clock);
+            var act = async () => await handler.Handle(new SubmitLeaveRequestCommand(leave.Id), CancellationToken.None);
+
+            await act.Should().ThrowAsync<ConflictException>().WithMessage("*Chưa chọn quy trình duyệt*");
+        }
+    }
+
+    // ============ Case 3: Approve advance (2-level, cấp 1) ============
+
+    [Fact]
+    public async Task Approve_FirstLevel_TwoLevel_AdvancesAndCreatesOneOpinion()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c3@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c3@test.local", "Approver 1", null, Array.Empty<string>());
+            var ap2 = await fix.CreateUserAsync("ap2-c3@test.local", "Approver 2", null, Array.Empty<string>());
+            var (wf, levels) = await SeedLeaveWorkflowAsync(db, ap1.Id, ap2.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            var handler = new ApproveLeaveRequestHandler(db, AsUser(ap1), clock);
+            await handler.Handle(new ApproveLeaveRequestCommand(leave.Id, "đồng ý"), CancellationToken.None);
+
+            leave.Status.Should().Be(WorkflowAppStatus.DaGuiDuyet, "còn Cấp 2 chưa terminal");
+            leave.CurrentApprovalLevelOrder.Should().Be(2);
+
+            var opinions = await db.LeaveRequestLevelOpinions.Where(o => o.LeaveRequestId == leave.Id).ToListAsync();
+            opinions.Should().HaveCount(1);
+            opinions[0].ApprovalWorkflowLevelId.Should().Be(levels[0].Id, "slot Cấp 1");
+            opinions[0].Comment.Should().Be("đồng ý");
+            opinions[0].SignedByUserId.Should().Be(ap1.Id);
+        }
+    }
+
+    // ============ Case 4: Approve terminal (cấp cuối) ============
+
+    [Fact]
+    public async Task Approve_LastLevel_TransitionsToDaDuyet_ClearsCurrentLevel()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c4@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c4@test.local", "Approver 1", null, Array.Empty<string>());
+            var ap2 = await fix.CreateUserAsync("ap2-c4@test.local", "Approver 2", null, Array.Empty<string>());
+            var (wf, _) = await SeedLeaveWorkflowAsync(db, ap1.Id, ap2.Id);
+
+            // pin tại Cấp cuối (2)
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 2);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            var handler = new ApproveLeaveRequestHandler(db, AsUser(ap2), clock);
+            await handler.Handle(new ApproveLeaveRequestCommand(leave.Id, "duyệt cuối"), CancellationToken.None);
+
+            leave.Status.Should().Be(WorkflowAppStatus.DaDuyet, "Cấp cuối → terminal");
+            leave.CurrentApprovalLevelOrder.Should().BeNull();
+
+            var opinions = await db.LeaveRequestLevelOpinions.Where(o => o.LeaveRequestId == leave.Id).ToListAsync();
+            opinions.Should().HaveCount(1, "1 row cho slot Cấp 2");
+        }
+    }
+
+    // ============ Case 5: Approve UPSERT invariant (re-sign same level) ============
+
+    [Fact]
+    public async Task Approve_SameLevelTwice_AdminReSign_DoesNotDuplicateRow_UpdatesLatestWrite()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c5@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c5@test.local", "Approver 1", null, Array.Empty<string>());
+            var ap2 = await fix.CreateUserAsync("ap2-c5@test.local", "Approver 2", null, Array.Empty<string>());
+            var admin = await fix.CreateUserAsync("admin-c5@test.local", "Quản trị", null, new[] { "Admin" });
+            var (wf, levels) = await SeedLeaveWorkflowAsync(db, ap1.Id, ap2.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            // 1st approve Cấp 1 bởi ap1 → tạo row, advance lên Cấp 2
+            await new ApproveLeaveRequestHandler(db, AsUser(ap1), clock)
+                .Handle(new ApproveLeaveRequestCommand(leave.Id, "ý kiến gốc"), CancellationToken.None);
+            leave.CurrentApprovalLevelOrder.Should().Be(2);
+
+            // Admin override re-sign Cấp 1: pin pointer trở lại Cấp 1 + admin duyệt lại
+            leave.CurrentApprovalLevelOrder = 1;
+            await db.SaveChangesAsync(CancellationToken.None);
+            await new ApproveLeaveRequestHandler(db, AsUser(admin, "Admin"), clock)
+                .Handle(new ApproveLeaveRequestCommand(leave.Id, "admin ký lại"), CancellationToken.None);
+
+            var opinions = await db.LeaveRequestLevelOpinions
+                .Where(o => o.LeaveRequestId == leave.Id && o.ApprovalWorkflowLevelId == levels[0].Id)
+                .ToListAsync();
+            opinions.Should().HaveCount(1, "UNIQUE composite — KHÔNG tạo row thứ 2");
+            opinions[0].Comment.Should().Be("admin ký lại", "latest-write-wins");
+            opinions[0].SignedByUserId.Should().Be(admin.Id, "signer cập nhật người ký mới nhất");
+        }
+    }
+
+    // ============ Case 6: Approve forbidden (outsider non-admin) ============
+
+    [Fact]
+    public async Task Approve_OutsiderNonAdmin_ThrowsForbidden_StateUnchanged()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c6@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c6@test.local", "Approver 1", null, Array.Empty<string>());
+            var outsider = await fix.CreateUserAsync("out-c6@test.local", "Outsider", null, Array.Empty<string>());
+            var (wf, _) = await SeedLeaveWorkflowAsync(db, ap1.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            var handler = new ApproveLeaveRequestHandler(db, AsUser(outsider), clock);
+            var act = async () => await handler.Handle(new ApproveLeaveRequestCommand(leave.Id, "thử duyệt"), CancellationToken.None);
+
+            await act.Should().ThrowAsync<ForbiddenException>().WithMessage("*Không phải người duyệt*");
+            leave.Status.Should().Be(WorkflowAppStatus.DaGuiDuyet, "guard chặn trước mutate");
+            leave.CurrentApprovalLevelOrder.Should().Be(1);
+            (await db.LeaveRequestLevelOpinions.CountAsync(o => o.LeaveRequestId == leave.Id))
+                .Should().Be(0, "không tạo opinion khi bị chặn");
+        }
+    }
+
+    // ============ Case 7: Approve empty comment → placeholder ============
+
+    [Fact]
+    public async Task Approve_EmptyComment_StoresPlaceholder()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c7@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c7@test.local", "Approver 1", null, Array.Empty<string>());
+            var (wf, levels) = await SeedLeaveWorkflowAsync(db, ap1.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await new ApproveLeaveRequestHandler(db, AsUser(ap1), clock)
+                .Handle(new ApproveLeaveRequestCommand(leave.Id, "   "), CancellationToken.None);
+
+            var opinion = await db.LeaveRequestLevelOpinions
+                .FirstAsync(o => o.LeaveRequestId == leave.Id && o.ApprovalWorkflowLevelId == levels[0].Id);
+            opinion.Comment.Should().Be("(duyệt — không ý kiến)");
+        }
+    }
+
+    // ============ Case 8a: Reject → TuChoi ============
+
+    [Fact]
+    public async Task Reject_FromDaGuiDuyet_TransitionsToTuChoi_ClearsCurrentLevel()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c8a@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c8a@test.local", "Approver 1", null, Array.Empty<string>());
+            var (wf, _) = await SeedLeaveWorkflowAsync(db, ap1.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await new RejectLeaveRequestHandler(db, AsUser(ap1), clock)
+                .Handle(new RejectLeaveRequestCommand(leave.Id, "không duyệt"), CancellationToken.None);
+
+            leave.Status.Should().Be(WorkflowAppStatus.TuChoi);
+            leave.CurrentApprovalLevelOrder.Should().BeNull();
+        }
+    }
+
+    // ============ Case 8b: Return → TraLai + RejectedFromStatus ============
+
+    [Fact]
+    public async Task Return_FromDaGuiDuyet_TransitionsToTraLai_SetsRejectedFromStatus()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-c8b@test.local", "Requester", null, Array.Empty<string>());
+            var ap1 = await fix.CreateUserAsync("ap1-c8b@test.local", "Approver 1", null, Array.Empty<string>());
+            var (wf, _) = await SeedLeaveWorkflowAsync(db, ap1.Id);
+
+            var leave = BuildLeave(requester.Id, wf.Id, WorkflowAppStatus.DaGuiDuyet, currentLevel: 1);
+            db.LeaveRequests.Add(leave);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await new ReturnLeaveRequestHandler(db, AsUser(ap1), clock)
+                .Handle(new ReturnLeaveRequestCommand(leave.Id, "sửa lại"), CancellationToken.None);
+
+            leave.Status.Should().Be(WorkflowAppStatus.TraLai);
+            leave.RejectedFromStatus.Should().Be(WorkflowAppStatus.DaGuiDuyet);
+            leave.CurrentApprovalLevelOrder.Should().BeNull();
+        }
+    }
+
+    // ============ Smoke OtRequest: mirror cookie-cutter — terminal happy path ============
+
+    [Fact]
+    public async Task OtRequest_Submit_Then_Approve_SingleLevel_ReachesDaDuyet()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync("req-ot@test.local", "Requester", null, Array.Empty<string>());
+            var approver = await fix.CreateUserAsync("ap-ot@test.local", "Approver", null, Array.Empty<string>());
+
+            var wf = new ApprovalWorkflow
+            {
+                Id = Guid.NewGuid(),
+                Code = "QT-OT-001",
+                Version = 1,
+                Name = "Quy trình OT test",
+                ApplicableType = ApprovalWorkflowApplicableType.OtRequest,
+                IsActive = true,
+                IsUserSelectable = true,
+            };
+            var step = new ApprovalWorkflowStep
+            {
+                Id = Guid.NewGuid(),
+                ApprovalWorkflowId = wf.Id,
+                Order = 1,
+                DepartmentId = null,
+                Name = "Bước 1",
+            };
+            var lvl = new ApprovalWorkflowLevel
+            {
+                Id = Guid.NewGuid(),
+                ApprovalWorkflowStepId = step.Id,
+                Order = 1,
+                ApproverUserId = approver.Id,
+            };
+            db.ApprovalWorkflows.Add(wf);
+            db.ApprovalWorkflowSteps.Add(step);
+            db.ApprovalWorkflowLevels.Add(lvl);
+
+            var ot = new OtRequest
+            {
+                Id = Guid.NewGuid(),
+                RequesterUserId = requester.Id,
+                RequesterFullName = "Người tạo",
+                OtDate = FixedNow.Date,
+                StartTime = TimeSpan.FromHours(18),
+                EndTime = TimeSpan.FromHours(21),
+                Hours = 3,
+                Reason = "Tăng ca giao hàng",
+                Status = WorkflowAppStatus.Nhap,
+                ApprovalWorkflowId = wf.Id,
+            };
+            db.OtRequests.Add(ot);
+            await db.SaveChangesAsync(CancellationToken.None);
+
+            await new SubmitOtRequestHandler(db, AsUser(requester), clock)
+                .Handle(new SubmitOtRequestCommand(ot.Id), CancellationToken.None);
+            ot.Status.Should().Be(WorkflowAppStatus.DaGuiDuyet);
+            ot.CurrentApprovalLevelOrder.Should().Be(1);
+            ot.MaDonTu.Should().Be("DT/OT/2026/001");
+
+            await new ApproveOtRequestHandler(db, AsUser(approver), clock)
+                .Handle(new ApproveOtRequestCommand(ot.Id, null), CancellationToken.None);
+            ot.Status.Should().Be(WorkflowAppStatus.DaDuyet);
+            ot.CurrentApprovalLevelOrder.Should().BeNull();
+
+            var opinions = await db.OtRequestLevelOpinions.Where(o => o.OtRequestId == ot.Id).ToListAsync();
+            opinions.Should().HaveCount(1);
+            opinions[0].Comment.Should().Be("(duyệt — không ý kiến)");
+        }
+    }
+}