[CLAUDE] Office: P11-D ItTicket auto-assign round-robin + SLA timer (Wave 2, Mig 46)

Mig 46 AddSlaFieldsToItTicket (SlaDueAt/SlaWarnedSent/SlaBreached). CreateItTicketHandler: round-robin least-loaded assign cho IT staff (dept Code=IT, tie-break Id) + SlaDueAt theo Priority (Urgent 4h/High 8h/Medium 24h/Low 72h). ItTicketSlaJob background (breach+warning notify, KHONG auto-transition). PUT /{id}/assign admin override. DbInitializer seed dept IT + 2 sample staff (nv.cao/nv.truong). FE ItTicketsPage +MaTicket+assignee+SLA badge (2 app SHA256 mirror). +9 test (191->200). Self-review PASS (seed<->query dept-code verified; em main solo review do session-limit kill reviewer-spawn).

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

fe-admin/src/pages/office/ItTicketsPage.tsx

@@ -1,5 +1,5 @@
-// Ticket CNTT — Phase 10.3 G-O6 (S38 2026-05-28).
+// Ticket CNTT — Phase 10.3 G-O6 (S38) + P11-D auto-assign round-robin + SLA timer (S52).
-// SKELETON Phase 1: read-only kanban list. Auto-assign + SLA timer DEFER Phase 11.
+// Read-only kanban list + MaTicket + người xử lý (auto-assign dept IT) + SLA badge (đỏ khi quá hạn).
 // File MIRROR SHA256 identical fe-user counterpart.
 import { useQuery } from '@tanstack/react-query'
 import { Ticket } from 'lucide-react'
@@ -11,6 +11,12 @@ import {
   IT_TICKET_STATUS_LABELS, type ItTicketDto, type PagedResult,
 } from '@/types/workflowApps'
 
+function formatSlaDue(iso: string): string {
+  return new Date(iso).toLocaleString('vi-VN', {
+    day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit',
+  })
+}
+
 export function ItTicketsPage() {
   const list = useQuery({
     queryKey: ['it-tickets'],
@@ -29,10 +35,6 @@ export function ItTicketsPage() {
     <div className="space-y-4">
       <PageHeader title="Ticket CNTT" description="Helpdesk — báo lỗi và yêu cầu hỗ trợ kỹ thuật" />
 
-      <div className="rounded-lg border bg-amber-50/50 p-3 text-sm text-amber-900">
-        ⚠️ <strong>Skeleton Phase 1 (S38):</strong> Read-only list. Form tạo ticket + Auto-assign round-robin + SLA timer defer Phase 11 polish.
-      </div>
-
       <div className="grid grid-cols-1 md:grid-cols-3 lg:grid-cols-5 gap-3">
         {[1, 2, 3, 5, 4].map((statusKey) => (
           <div key={statusKey} className="rounded-lg border bg-card p-3">
@@ -56,6 +58,22 @@ export function ItTicketsPage() {
                   <div className="text-muted-foreground">
                     {IT_TICKET_CATEGORY_LABELS[t.category]} · {t.requesterFullName}
                   </div>
+                  <div className="flex items-center justify-between gap-1 pt-0.5">
+                    <span className="text-muted-foreground truncate" title={t.assignedToFullName ?? undefined}>
+                      👤 {t.assignedToFullName ?? <span className="italic">Chưa giao</span>}
+                    </span>
+                    {t.slaDueAt && (
+                      <span
+                        className={cn(
+                          'rounded px-1.5 py-0.5 text-[10px] whitespace-nowrap',
+                          t.slaBreached ? 'bg-red-100 text-red-700 font-medium' : 'bg-slate-100 text-slate-600',
+                        )}
+                        title={`Hạn xử lý SLA: ${formatSlaDue(t.slaDueAt)}`}
+                      >
+                        {t.slaBreached ? 'Quá hạn SLA' : `SLA ${formatSlaDue(t.slaDueAt)}`}
+                      </span>
+                    )}
+                  </div>
                 </div>
               ))}
             </div>
@@ -66,7 +84,7 @@ export function ItTicketsPage() {
       {!list.isLoading && items.length === 0 && (
         <div className="rounded-lg border bg-card p-8 text-center text-muted-foreground">
           <Ticket className="mx-auto h-10 w-10 mb-3 opacity-50" />
-          Chưa có ticket nào. Form tạo ticket sẽ kích hoạt Phase 11.
+          Chưa có ticket nào.
         </div>
       )}
     </div>

fe-admin/src/types/workflowApps.ts

@@ -114,7 +114,7 @@ export interface LeaveRequestDto { id: string; maDonTu: string | null; requester
 export interface OtRequestDto { id: string; maDonTu: string | null; requesterUserId: string; requesterFullName: string; otDate: string; startTime: string; endTime: string; hours: number; reason: string; otPolicyId: string | null; status: number; approvalWorkflowId: string | null; currentApprovalLevelOrder: number | null; createdAt: string }
 export interface TravelRequestDto { id: string; maDonTu: string | null; requesterUserId: string; requesterFullName: string; destination: string; startDate: string; endDate: string; numDays: number; purpose: string; estimatedCost: number | null; status: number; approvalWorkflowId: string | null; currentApprovalLevelOrder: number | null; createdAt: string }
 export interface VehicleBookingDto { id: string; maDonTu: string | null; requesterUserId: string; requesterFullName: string; vehicleLicense: string; vehicleName: string | null; startAt: string; endAt: string; destination: string; purpose: string; driverName: string | null; status: number; approvalWorkflowId: string | null; currentApprovalLevelOrder: number | null; createdAt: string }
-export interface ItTicketDto { id: string; maTicket: string | null; requesterUserId: string; requesterFullName: string; title: string; description: string; category: number; priority: number; status: number; assignedToUserId: string | null; assignedToFullName: string | null; resolvedAt: string | null; resolution: string | null; createdAt: string }
+export interface ItTicketDto { id: string; maTicket: string | null; requesterUserId: string; requesterFullName: string; title: string; description: string; category: number; priority: number; status: number; assignedToUserId: string | null; assignedToFullName: string | null; resolvedAt: string | null; resolution: string | null; createdAt: string; slaDueAt: string | null; slaBreached: boolean }
 export interface AttendanceDto { id: string; userId: string; userFullName: string; attendanceDate: string; checkInAt: string | null; checkOutAt: string | null; sourceIn: number; sourceOut: number; checkInLatitude: number | null; checkInLongitude: number | null; workHours: number | null; otHours: number | null; note: string | null }
 
 // P11-E (S?? 2026-06-08) — Báo cáo chấm công tháng + OT quy đổi (admin-only). Mirror BE AttendanceReportDto/RowDto (decimal → number).

fe-user/src/pages/office/ItTicketsPage.tsx

@@ -1,5 +1,5 @@
-// Ticket CNTT — Phase 10.3 G-O6 (S38 2026-05-28).
+// Ticket CNTT — Phase 10.3 G-O6 (S38) + P11-D auto-assign round-robin + SLA timer (S52).
-// SKELETON Phase 1: read-only kanban list. Auto-assign + SLA timer DEFER Phase 11.
+// Read-only kanban list + MaTicket + người xử lý (auto-assign dept IT) + SLA badge (đỏ khi quá hạn).
 // File MIRROR SHA256 identical fe-user counterpart.
 import { useQuery } from '@tanstack/react-query'
 import { Ticket } from 'lucide-react'
@@ -11,6 +11,12 @@ import {
   IT_TICKET_STATUS_LABELS, type ItTicketDto, type PagedResult,
 } from '@/types/workflowApps'
 
+function formatSlaDue(iso: string): string {
+  return new Date(iso).toLocaleString('vi-VN', {
+    day: '2-digit', month: '2-digit', hour: '2-digit', minute: '2-digit',
+  })
+}
+
 export function ItTicketsPage() {
   const list = useQuery({
     queryKey: ['it-tickets'],
@@ -29,10 +35,6 @@ export function ItTicketsPage() {
     <div className="space-y-4">
       <PageHeader title="Ticket CNTT" description="Helpdesk — báo lỗi và yêu cầu hỗ trợ kỹ thuật" />
 
-      <div className="rounded-lg border bg-amber-50/50 p-3 text-sm text-amber-900">
-        ⚠️ <strong>Skeleton Phase 1 (S38):</strong> Read-only list. Form tạo ticket + Auto-assign round-robin + SLA timer defer Phase 11 polish.
-      </div>
-
       <div className="grid grid-cols-1 md:grid-cols-3 lg:grid-cols-5 gap-3">
         {[1, 2, 3, 5, 4].map((statusKey) => (
           <div key={statusKey} className="rounded-lg border bg-card p-3">
@@ -56,6 +58,22 @@ export function ItTicketsPage() {
                   <div className="text-muted-foreground">
                     {IT_TICKET_CATEGORY_LABELS[t.category]} · {t.requesterFullName}
                   </div>
+                  <div className="flex items-center justify-between gap-1 pt-0.5">
+                    <span className="text-muted-foreground truncate" title={t.assignedToFullName ?? undefined}>
+                      👤 {t.assignedToFullName ?? <span className="italic">Chưa giao</span>}
+                    </span>
+                    {t.slaDueAt && (
+                      <span
+                        className={cn(
+                          'rounded px-1.5 py-0.5 text-[10px] whitespace-nowrap',
+                          t.slaBreached ? 'bg-red-100 text-red-700 font-medium' : 'bg-slate-100 text-slate-600',
+                        )}
+                        title={`Hạn xử lý SLA: ${formatSlaDue(t.slaDueAt)}`}
+                      >
+                        {t.slaBreached ? 'Quá hạn SLA' : `SLA ${formatSlaDue(t.slaDueAt)}`}
+                      </span>
+                    )}
+                  </div>
                 </div>
               ))}
             </div>
@@ -66,7 +84,7 @@ export function ItTicketsPage() {
       {!list.isLoading && items.length === 0 && (
         <div className="rounded-lg border bg-card p-8 text-center text-muted-foreground">
           <Ticket className="mx-auto h-10 w-10 mb-3 opacity-50" />
-          Chưa có ticket nào. Form tạo ticket sẽ kích hoạt Phase 11.
+          Chưa có ticket nào.
         </div>
       )}
     </div>

fe-user/src/types/workflowApps.ts

@@ -114,6 +114,6 @@ export interface LeaveRequestDto { id: string; maDonTu: string | null; requester
 export interface OtRequestDto { id: string; maDonTu: string | null; requesterUserId: string; requesterFullName: string; otDate: string; startTime: string; endTime: string; hours: number; reason: string; otPolicyId: string | null; status: number; approvalWorkflowId: string | null; currentApprovalLevelOrder: number | null; createdAt: string }
 export interface TravelRequestDto { id: string; maDonTu: string | null; requesterUserId: string; requesterFullName: string; destination: string; startDate: string; endDate: string; numDays: number; purpose: string; estimatedCost: number | null; status: number; approvalWorkflowId: string | null; currentApprovalLevelOrder: number | null; createdAt: string }
 export interface VehicleBookingDto { id: string; maDonTu: string | null; requesterUserId: string; requesterFullName: string; vehicleLicense: string; vehicleName: string | null; startAt: string; endAt: string; destination: string; purpose: string; driverName: string | null; status: number; approvalWorkflowId: string | null; currentApprovalLevelOrder: number | null; createdAt: string }
-export interface ItTicketDto { id: string; maTicket: string | null; requesterUserId: string; requesterFullName: string; title: string; description: string; category: number; priority: number; status: number; assignedToUserId: string | null; assignedToFullName: string | null; resolvedAt: string | null; resolution: string | null; createdAt: string }
+export interface ItTicketDto { id: string; maTicket: string | null; requesterUserId: string; requesterFullName: string; title: string; description: string; category: number; priority: number; status: number; assignedToUserId: string | null; assignedToFullName: string | null; resolvedAt: string | null; resolution: string | null; createdAt: string; slaDueAt: string | null; slaBreached: boolean }
 export interface AttendanceDto { id: string; userId: string; userFullName: string; attendanceDate: string; checkInAt: string | null; checkOutAt: string | null; sourceIn: number; sourceOut: number; checkInLatitude: number | null; checkInLongitude: number | null; workHours: number | null; otHours: number | null; note: string | null }
 export interface HrDashboardDto { totalEmployees: number; activeEmployees: number; onLeaveEmployees: number; resignedEmployees: number; maleCount: number; femaleCount: number; birthdaysThisWeek: number; newHiresThisMonth: number }

src/Backend/SolutionErp.Api/Controllers/ItTicketsController.cs

@@ -29,5 +29,15 @@ public class ItTicketsController(IMediator mediator) : ControllerBase
         return NoContent();
     }
 
-    public record UpdateItTicketStatusBody(int Status, string? Resolution);
+    // P11-D: admin re-assign ticket cho IT staff (override round-robin auto-assign).
+    [HttpPut("{id:guid}/assign")]
+    [Authorize(Roles = "Admin")]
+    public async Task<IActionResult> Assign(Guid id, [FromBody] AssignItTicketBody body)
+    {
+        await mediator.Send(new AssignItTicketCommand(id, body.AssignedToUserId));
+        return NoContent();
+    }
+
+    public record UpdateItTicketStatusBody(int Status, string? Resolution);
+    public record AssignItTicketBody(Guid AssignedToUserId);
 }

src/Backend/SolutionErp.Application/Office/WorkflowAppsFeatures.cs

@@ -312,7 +312,8 @@ public class GetVehicleBookingsHandler(IApplicationDbContext db)
 
 public record ItTicketDto(Guid Id, string? MaTicket, Guid RequesterUserId, string RequesterFullName,
     string Title, string Description, int Category, int Priority, int Status,
-    Guid? AssignedToUserId, string? AssignedToFullName, DateTime? ResolvedAt, string? Resolution, DateTime CreatedAt);
+    Guid? AssignedToUserId, string? AssignedToFullName, DateTime? ResolvedAt, string? Resolution, DateTime CreatedAt,
+    DateTime? SlaDueAt, bool SlaBreached);
 
 public record CreateItTicketCommand(string Title, string Description, int Category, int Priority) : IRequest<Guid>;
 
@@ -330,9 +331,21 @@ public class CreateItTicketValidator : AbstractValidator<CreateItTicketCommand>
 public class CreateItTicketHandler(IApplicationDbContext db, ICurrentUser cu, IDateTime clock)
     : IRequestHandler<CreateItTicketCommand, Guid>
 {
+    // P11-D (Mig 46) — SLA window theo Priority. Source-of-truth shared với
+    // ItTicketSlaJob (warning/breach tính cùng map). Urgent gấp nhất → 4h.
+    public static readonly IReadOnlyDictionary<ItTicketPriority, TimeSpan> SlaWindow =
+        new Dictionary<ItTicketPriority, TimeSpan>
+        {
+            [ItTicketPriority.Urgent] = TimeSpan.FromHours(4),
+            [ItTicketPriority.High] = TimeSpan.FromHours(8),
+            [ItTicketPriority.Medium] = TimeSpan.FromHours(24),
+            [ItTicketPriority.Low] = TimeSpan.FromHours(72),
+        };
+
     public async Task<Guid> Handle(CreateItTicketCommand req, CancellationToken ct)
     {
         if (cu.UserId is null) throw new UnauthorizedException();
+        var priority = (ItTicketPriority)req.Priority;
         var e = new ItTicket
         {
             RequesterUserId = cu.UserId.Value,
@@ -340,7 +353,7 @@ public class CreateItTicketHandler(IApplicationDbContext db, ICurrentUser cu, ID
             Title = req.Title.Trim(),
             Description = req.Description.Trim(),
             Category = (ItTicketCategory)req.Category,
-            Priority = (ItTicketPriority)req.Priority,
+            Priority = priority,
             Status = ItTicketStatus.Open,
             CreatedAt = clock.UtcNow,
             CreatedBy = cu.UserId,
@@ -348,6 +361,32 @@ public class CreateItTicketHandler(IApplicationDbContext db, ICurrentUser cu, ID
         // P11-F: gen mã ticket lúc Create (ItTicket = kanban KHÔNG workflow,
         // khác Leave/OT gen lúc Submit). Format "IT/2026/001" (Serializable tx atomic).
         e.MaTicket = await WorkflowAppCodeGen.GenerateMaDonTuAsync(db, "IT", clock.Now.Year, clock, ct);
+
+        // P11-D: SLA due = CreatedAt + window theo Priority (default Medium 24h nếu lạ).
+        e.SlaDueAt = e.CreatedAt + (SlaWindow.TryGetValue(priority, out var w) ? w : TimeSpan.FromHours(24));
+
+        // P11-D: round-robin least-loaded — assign cho IT staff (Department.Code=="IT")
+        // ít ticket-mở nhất. Tie-break theo Id (deterministic). Không có ai trong IT
+        // → để unassigned (admin assign tay sau qua /assign).
+        var itDeptId = await db.Departments.AsNoTracking()
+            .Where(d => d.Code == "IT" && !d.IsDeleted)
+            .Select(d => (Guid?)d.Id)
+            .FirstOrDefaultAsync(ct);
+        if (itDeptId is Guid deptId)
+        {
+            var assignee = await db.Users
+                .Where(u => u.DepartmentId == deptId && u.IsActive)
+                .OrderBy(u => db.ItTickets.Count(t => t.AssignedToUserId == u.Id
+                    && t.Status != ItTicketStatus.Closed && t.Status != ItTicketStatus.Resolved && !t.IsDeleted))
+                .ThenBy(u => u.Id)
+                .FirstOrDefaultAsync(ct);
+            if (assignee is not null)
+            {
+                e.AssignedToUserId = assignee.Id;
+                e.AssignedToFullName = assignee.FullName;
+            }
+        }
+
         db.ItTickets.Add(e);
         await db.SaveChangesAsync(ct);
         return e.Id;
@@ -374,7 +413,8 @@ public class GetItTicketsHandler(IApplicationDbContext db)
         var items = await query.OrderByDescending(x => x.CreatedAt).Skip((page - 1) * pageSize).Take(pageSize)
             .Select(x => new ItTicketDto(x.Id, x.MaTicket, x.RequesterUserId, x.RequesterFullName,
                 x.Title, x.Description, (int)x.Category, (int)x.Priority, (int)x.Status,
-                x.AssignedToUserId, x.AssignedToFullName, x.ResolvedAt, x.Resolution, x.CreatedAt))
+                x.AssignedToUserId, x.AssignedToFullName, x.ResolvedAt, x.Resolution, x.CreatedAt,
+                x.SlaDueAt, x.SlaBreached))
             .ToListAsync(ct);
         return new PagedResult<ItTicketDto>(items, total, page, pageSize);
     }
@@ -400,6 +440,38 @@ public class UpdateItTicketStatusHandler(IApplicationDbContext db, ICurrentUser
     }
 }
 
+// P11-D: admin re-assign ticket cho IT staff cụ thể (override round-robin auto-assign
+// lúc Create). Denorm AssignedToFullName từ User.FullName tại thời điểm gán.
+public record AssignItTicketCommand(Guid Id, Guid AssignedToUserId) : IRequest;
+
+public class AssignItTicketValidator : AbstractValidator<AssignItTicketCommand>
+{
+    public AssignItTicketValidator()
+    {
+        RuleFor(x => x.Id).NotEmpty();
+        RuleFor(x => x.AssignedToUserId).NotEmpty();
+    }
+}
+
+public class AssignItTicketHandler(IApplicationDbContext db, ICurrentUser cu, IDateTime clock)
+    : IRequestHandler<AssignItTicketCommand>
+{
+    public async Task Handle(AssignItTicketCommand req, CancellationToken ct)
+    {
+        if (cu.UserId is null) throw new UnauthorizedException();
+        var t = await db.ItTickets.FirstOrDefaultAsync(x => x.Id == req.Id && !x.IsDeleted, ct);
+        if (t is null) throw new NotFoundException("ItTicket", req.Id);
+        var assignee = await db.Users.AsNoTracking()
+            .FirstOrDefaultAsync(u => u.Id == req.AssignedToUserId && u.IsActive, ct);
+        if (assignee is null) throw new NotFoundException("User", req.AssignedToUserId);
+        t.AssignedToUserId = assignee.Id;
+        t.AssignedToFullName = assignee.FullName;
+        t.UpdatedAt = clock.UtcNow;
+        t.UpdatedBy = cu.UserId;
+        await db.SaveChangesAsync(ct);
+    }
+}
+
 // =========================================================================
 // REGION 6: Attendance (G-P1)
 // =========================================================================

src/Backend/SolutionErp.Domain/Office/ItTicket.cs

@@ -23,4 +23,12 @@ public class ItTicket : AuditableEntity
 
     public DateTime? ResolvedAt { get; set; }
     public string? Resolution { get; set; }               // ghi chú giải pháp (free text replace ItTicketComments thread defer Phase 11)
+
+    // P11-D (Mig 46 — Wave 2) — SLA timer. SlaDueAt = CreatedAt + window theo Priority
+    // (Urgent=4h / High=8h / Medium=24h / Low=72h). ItTicketSlaJob (BackgroundService
+    // 15 phút) set SlaWarnedSent khi còn ≤20% window + SlaBreached khi quá hạn (notify
+    // assignee). NO auto-transition status (khác SlaExpiryJob của HĐ — ticket chỉ cảnh báo).
+    public DateTime? SlaDueAt { get; set; }
+    public bool SlaWarnedSent { get; set; }
+    public bool SlaBreached { get; set; }
 }

src/Backend/SolutionErp.Infrastructure/DependencyInjection.cs

@@ -45,6 +45,8 @@ public static class DependencyInjection
 
         // Phase 3 iteration 2 — SLA auto-approve background service
         services.AddHostedService<SlaExpiryJob>();
+        // Phase 11 P11-D — IT ticket SLA timer (warning ≤20% + breach, no auto-transition)
+        services.AddHostedService<ItTicketSlaJob>();
 
         services.AddScoped<AuditingInterceptor>();
         services.AddScoped<NotificationPushInterceptor>();

src/Backend/SolutionErp.Infrastructure/HostedServices/ItTicketSlaJob.cs

@@ -0,0 +1,143 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using SolutionErp.Application.Common.Interfaces;
+using SolutionErp.Application.Notifications;
+using SolutionErp.Application.Office;
+using SolutionErp.Domain.Notifications;
+using SolutionErp.Domain.Office;
+
+namespace SolutionErp.Infrastructure.HostedServices;
+
+// P11-D (Mig 46 — Phase 11 Wave 2) — SLA timer cho IT helpdesk ticket.
+// Mirror pattern SlaExpiryJob (HĐ) NHƯNG KHÔNG auto-transition status — ticket
+// chỉ CẢNH BÁO (warning ≤20% window + breach quá hạn) gửi notification cho assignee.
+// Status flow (Open → InProgress → Resolved → Closed) do IT staff điều khiển tay.
+// Chạy mỗi 15 phút, warmup 30s tránh race DbInitializer migrate.
+// SLA window theo Priority = source-of-truth CreateItTicketHandler.SlaWindow (shared).
+public class ItTicketSlaJob : BackgroundService
+{
+    private readonly IServiceProvider _sp;
+    private readonly ILogger<ItTicketSlaJob> _logger;
+    private static readonly TimeSpan Interval = TimeSpan.FromMinutes(15);
+
+    public ItTicketSlaJob(IServiceProvider sp, ILogger<ItTicketSlaJob> logger)
+    {
+        _sp = sp;
+        _logger = logger;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        await Task.Delay(TimeSpan.FromSeconds(30), stoppingToken);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                await ProcessAsync(stoppingToken);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "ItTicketSlaJob iteration failed");
+            }
+            await Task.Delay(Interval, stoppingToken);
+        }
+    }
+
+    private async Task ProcessAsync(CancellationToken ct)
+    {
+        await using var scope = _sp.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<IApplicationDbContext>();
+        var dateTime = scope.ServiceProvider.GetRequiredService<IDateTime>();
+        var notifications = scope.ServiceProvider.GetRequiredService<INotificationService>();
+
+        var now = dateTime.UtcNow;
+
+        await ProcessBreachesAsync(db, notifications, now, ct);
+        await ProcessWarningsAsync(db, notifications, now, ct);
+    }
+
+    // Breach: ticket quá hạn SLA mà chưa đánh dấu breach + còn open (chưa Resolved/Closed).
+    // Set SlaBreached=true + notify assignee (nếu có). Idempotent qua !SlaBreached guard.
+    private async Task ProcessBreachesAsync(
+        IApplicationDbContext db, INotificationService notifications,
+        DateTime now, CancellationToken ct)
+    {
+        var breached = await db.ItTickets
+            .Where(t => t.SlaDueAt != null && t.SlaDueAt < now
+                && !t.SlaBreached
+                && t.Status != ItTicketStatus.Resolved && t.Status != ItTicketStatus.Closed
+                && !t.IsDeleted)
+            .ToListAsync(ct);
+
+        if (breached.Count == 0) return;
+
+        foreach (var t in breached)
+        {
+            if (t.AssignedToUserId is Guid assignee)
+            {
+                await notifications.NotifyAsync(
+                    assignee,
+                    NotificationType.SlaWarning,
+                    title: $"⚠ Ticket {t.MaTicket ?? t.Title} quá hạn SLA",
+                    description: $"Ticket \"{t.Title}\" đã quá hạn xử lý SLA. Vui lòng ưu tiên xử lý.",
+                    href: $"/it-tickets/{t.Id}",
+                    refId: t.Id,
+                    ct: ct);
+            }
+            t.SlaBreached = true;
+        }
+
+        await db.SaveChangesAsync(ct);
+        _logger.LogInformation("ItTicketSlaJob: {Count} tickets breached SLA.", breached.Count);
+    }
+
+    // Warning: ticket chưa warning + còn open + còn ≤20% window (theo Priority) trước hạn.
+    // Notify assignee + set SlaWarnedSent=true. Idempotent qua !SlaWarnedSent guard.
+    private async Task ProcessWarningsAsync(
+        IApplicationDbContext db, INotificationService notifications,
+        DateTime now, CancellationToken ct)
+    {
+        var candidates = await db.ItTickets
+            .Where(t => !t.SlaWarnedSent
+                && t.SlaDueAt != null && t.SlaDueAt > now
+                && t.Status != ItTicketStatus.Resolved && t.Status != ItTicketStatus.Closed
+                && !t.IsDeleted)
+            .ToListAsync(ct);
+
+        if (candidates.Count == 0) return;
+
+        int warned = 0;
+        foreach (var t in candidates)
+        {
+            var window = CreateItTicketHandler.SlaWindow.TryGetValue(t.Priority, out var w)
+                ? w : TimeSpan.FromHours(24);
+            var threshold = TimeSpan.FromTicks((long)(window.Ticks * 0.2));
+            var remaining = t.SlaDueAt!.Value - now;
+            if (remaining > threshold) continue;       // còn nhiều SLA → skip
+
+            if (t.AssignedToUserId is Guid assignee)
+            {
+                var hoursLeft = Math.Max(1, (int)remaining.TotalHours);
+                await notifications.NotifyAsync(
+                    assignee,
+                    NotificationType.SlaWarning,
+                    title: $"⚠ Ticket {t.MaTicket ?? t.Title} sắp quá hạn ({hoursLeft}h)",
+                    description: $"Ticket \"{t.Title}\" còn ~{hoursLeft}h trước hạn xử lý SLA.",
+                    href: $"/it-tickets/{t.Id}",
+                    refId: t.Id,
+                    ct: ct);
+            }
+            t.SlaWarnedSent = true;
+            warned++;
+        }
+
+        if (warned > 0)
+        {
+            await db.SaveChangesAsync(ct);
+            _logger.LogInformation("ItTicketSlaJob: {Count} warnings dispatched (≤20% SLA).", warned);
+        }
+    }
+}

src/Backend/SolutionErp.Infrastructure/Persistence/DbInitializer.cs

@@ -88,6 +88,10 @@ public static class DbInitializer
         await SeedAdminAsync(userManager, logger);
         await SeedDepartmentsAsync(db, logger);
         await SeedDemoUsersAsync(db, userManager, logger);
+        // Phase 11 P11-D (Mig 46 — Wave 2) — gán 2 sample user vào Phòng CNTT (IT staff)
+        // cho round-robin auto-assign ticket. PHẢI sau SeedDemoUsersAsync (reconcile dept
+        // trước → method này override về IT). Infrastructure data (NOT gated DemoSeed).
+        await SeedItDepartmentStaffAsync(db, userManager, logger);
         // Plan B G-H1 (Mig 34 S33 2026-05-26) — seed EmployeeProfile 1-1 với
         // mọi user @solutions.com.vn. Idempotent. NOT gated DemoSeed flag
         // (infrastructure data, mirror Mig 32 SeedSampleContractWorkflowV2
@@ -2074,6 +2078,7 @@ public static class DbInitializer
             ("EQU", "Phòng Thiết bị",               "Equipment — thuê/mua máy móc"),
             ("HRA", "Phòng Nhân sự - Hành chính",   "HRA/ISO — đóng dấu HĐ sau BOD ký"),
             ("BOD", "Ban Giám đốc",                 "Board of Directors — ký duyệt HĐ"),
+            ("IT",  "Phòng CNTT",                   "IT helpdesk — tiếp nhận + xử lý ticket CNTT (P11-D round-robin assign)"),
         };
 
         var existingCodes = await db.Departments.Select(d => d.Code).ToListAsync();
@@ -2091,6 +2096,52 @@ public static class DbInitializer
         }
     }
 
+    // P11-D (Wave 2) — gán 2 SAMPLE demo user vào Phòng CNTT (IT) làm IT staff
+    // để round-robin auto-assign ticket có người nhận ngày 1. CHỈ đụng 2 sample
+    // user (nv.cao + nv.truong — prefix nv.* = sample, KHÔNG phải 14 Solutions
+    // real user). Idempotent: chỉ set DepartmentId nếu user CHƯA thuộc IT.
+    //
+    // ⚠️ PHẢI chạy SAU SeedDemoUsersAsync: method đó reconcile DepartmentId 2 user
+    // này về PRO/CCM (hardcoded deptCode) mỗi lần boot. Chạy sau → override về IT.
+    // End-state sau mỗi full SeedAsync = deterministic (IT). Infrastructure data
+    // (NOT gated DemoSeed flag, gotcha #51).
+    private static async Task SeedItDepartmentStaffAsync(
+        ApplicationDbContext db, UserManager<User> userManager, ILogger logger)
+    {
+        var itDept = await db.Departments.FirstOrDefaultAsync(d => d.Code == "IT" && !d.IsDeleted);
+        if (itDept is null)
+        {
+            logger.LogWarning("SeedItDepartmentStaffAsync: skip — phòng IT chưa seed (chạy SeedDepartmentsAsync trước).");
+            return;
+        }
+
+        // 2 sample user (Drafter-only) chuyển sang IT staff. KHÔNG đụng real user.
+        var sampleItStaffEmails = new[]
+        {
+            "nv.cao@solutions.com.vn",      // Cao Văn Long
+            "nv.truong@solutions.com.vn",   // Trương Minh Quân
+        };
+
+        int assigned = 0;
+        foreach (var email in sampleItStaffEmails)
+        {
+            var user = await userManager.FindByEmailAsync(email);
+            if (user is null)
+            {
+                logger.LogWarning("SeedItDepartmentStaffAsync: sample user {Email} not found — skip.", email);
+                continue;
+            }
+            if (user.DepartmentId == itDept.Id) continue;   // đã thuộc IT → idempotent skip
+            user.DepartmentId = itDept.Id;
+            user.UpdatedAt = DateTime.UtcNow;
+            await userManager.UpdateAsync(user);
+            assigned++;
+        }
+
+        if (assigned > 0)
+            logger.LogInformation("SeedItDepartmentStaffAsync: gán {Count} sample user vào Phòng CNTT (IT staff).", assigned);
+    }
+
     // Sample master data for UAT/demo — per-code idempotent (skip Code đã có,
     // add Code mới). Cho phép admin add/sửa supplier/project mà restart không
     // clobber, đồng thời cho phép expand seed list theo thời gian.

src/Backend/SolutionErp.Infrastructure/Persistence/Migrations/20260608054312_AddSlaFieldsToItTicket.cs

@@ -0,0 +1,51 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace SolutionErp.Infrastructure.Persistence.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddSlaFieldsToItTicket : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<bool>(
+                name: "SlaBreached",
+                table: "ItTickets",
+                type: "bit",
+                nullable: false,
+                defaultValue: false);
+
+            migrationBuilder.AddColumn<DateTime>(
+                name: "SlaDueAt",
+                table: "ItTickets",
+                type: "datetime2",
+                nullable: true);
+
+            migrationBuilder.AddColumn<bool>(
+                name: "SlaWarnedSent",
+                table: "ItTickets",
+                type: "bit",
+                nullable: false,
+                defaultValue: false);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "SlaBreached",
+                table: "ItTickets");
+
+            migrationBuilder.DropColumn(
+                name: "SlaDueAt",
+                table: "ItTickets");
+
+            migrationBuilder.DropColumn(
+                name: "SlaWarnedSent",
+                table: "ItTickets");
+        }
+    }
+}

src/Backend/SolutionErp.Infrastructure/Persistence/Migrations/ApplicationDbContextModelSnapshot.cs

@@ -3793,6 +3793,15 @@ namespace SolutionErp.Infrastructure.Persistence.Migrations
                     b.Property<DateTime?>("ResolvedAt")
                         .HasColumnType("datetime2");
 
+                    b.Property<bool>("SlaBreached")
+                        .HasColumnType("bit");
+
+                    b.Property<DateTime?>("SlaDueAt")
+                        .HasColumnType("datetime2");
+
+                    b.Property<bool>("SlaWarnedSent")
+                        .HasColumnType("bit");
+
                     b.Property<int>("Status")
                         .HasColumnType("int");
 

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

@@ -0,0 +1,233 @@
+using System.Text.RegularExpressions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using SolutionErp.Application.Office;
+using SolutionErp.Domain.Identity;
+using SolutionErp.Domain.Master;
+using SolutionErp.Domain.Office;
+using SolutionErp.Infrastructure.Tests.Common;
+
+namespace SolutionErp.Infrastructure.Tests.Application;
+
+// Phase 11 P11-D (S53 2026-06-08 — Wave 2) — test-after CreateItTicketHandler
+// round-robin auto-assign + SLA-due theo Priority.
+//
+// READ src: WorkflowAppsFeatures.cs CreateItTicketHandler:
+//   - SlaWindow map (dòng ~336): Urgent=4h / High=8h / Medium=24h / Low=72h
+//     → e.SlaDueAt = e.CreatedAt + window (default Medium 24h nếu Priority lạ).
+//   - Round-robin (dòng ~371-388): tìm Department.Code=="IT" (&& !IsDeleted) →
+//     trong dept đó pick user IsActive ÍT ticket-mở nhất (Status != Closed && != Resolved
+//     && !IsDeleted) → OrderBy(count).ThenBy(u.Id) → least-loaded + tie-break Id.
+//     Không có dept IT / 0 user active IT → AssignedToUserId == null (unassigned).
+//
+// ⚠️ Tie-break ThenBy(u.Id) so theo Guid — CreateUserAsync dùng Guid.NewGuid() nên
+// KHÔNG hardcode được "A thắng B". Assert động: tính expected = user có Id nhỏ hơn
+// (Guid CompareTo) tại runtime, so với AssignedToUserId thực tế.
+//
+// GOTCHA Serializable-on-SQLite = NON-ISSUE (confirmed S52 ItTicketCodeGenTests):
+// codegen MaTicket dùng BeginTransactionAsync(IsolationLevel.Serializable) chạy SẠCH
+// trên SQLite (provider map isolation gracefully, no throw). Mọi Create dưới đây gen
+// MaTicket bình thường — Case regression (3) verify lại format không vỡ khi handler đổi.
+public class ItTicketAssignSlaTests
+{
+    private static readonly DateTime FixedNow = new(2026, 6, 8, 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)
+        => new() { UserId = u.Id, FullName = u.FullName, Roles = Array.Empty<string>() };
+
+    private static CreateItTicketCommand BuildCmd(int priority = 2, string title = "Máy in hỏng")
+        => new(title, "Máy in tầng 3 không nhận lệnh in.", Category: 1, Priority: priority);
+
+    // Seed 1 Department với Code chỉ định, trả về Id.
+    private static async Task<Guid> SeedDeptAsync(TestApplicationDbContext db, string code, string name)
+    {
+        var dept = new Department { Id = Guid.NewGuid(), Code = code, Name = name };
+        db.Departments.Add(dept);
+        await db.SaveChangesAsync(CancellationToken.None);
+        return dept.Id;
+    }
+
+    // Seed 1 ticket OPEN đã assign cho user (mô phỏng "load sẵn") — bỏ qua codegen.
+    private static async Task SeedOpenTicketAsync(TestApplicationDbContext db, Guid assigneeId, DateTime createdAt)
+    {
+        db.ItTickets.Add(new ItTicket
+        {
+            Id = Guid.NewGuid(),
+            MaTicket = "IT/2026/900",                 // mã seed thủ công, không đụng sequence
+            RequesterUserId = assigneeId,
+            RequesterFullName = "seed",
+            Title = "Ticket seed",
+            Description = "load sẵn",
+            Category = ItTicketCategory.Hardware,
+            Priority = ItTicketPriority.Medium,
+            Status = ItTicketStatus.Open,
+            AssignedToUserId = assigneeId,
+            CreatedAt = createdAt,
+        });
+        await db.SaveChangesAsync(CancellationToken.None);
+    }
+
+    // ============ Case 1: Round-robin least-loaded + tie-break deterministic ============
+
+    [Fact]
+    public async Task CreateItTicket_RoundRobin_PicksLeastLoadedThenTieBreaksById()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var itDeptId = await SeedDeptAsync(db, "IT", "Phòng CNTT");
+            var requester = await fix.CreateUserAsync("req-rr1@test.local", "Người tạo", null, Array.Empty<string>());
+
+            // 2 IT staff active, A có sẵn 1 ticket mở → load A=1, B=0.
+            var staffA = await fix.CreateUserAsync("it-a@test.local", "IT Staff A", itDeptId, Array.Empty<string>());
+            var staffB = await fix.CreateUserAsync("it-b@test.local", "IT Staff B", itDeptId, Array.Empty<string>());
+            await SeedOpenTicketAsync(db, staffA.Id, clock.UtcNow);
+
+            var handler = new CreateItTicketHandler(db, AsUser(requester), clock);
+
+            // Create #1 → B (load 0) thắng A (load 1).
+            var id1 = await handler.Handle(BuildCmd(), CancellationToken.None);
+            var t1 = await db.ItTickets.FirstAsync(t => t.Id == id1);
+            t1.AssignedToUserId.Should().Be(staffB.Id, "B load=0 < A load=1 → least-loaded");
+            t1.AssignedToFullName.Should().Be("IT Staff B", "denorm full name set cùng assignee");
+
+            // Create #2 → giờ A=1, B=1 tie → ThenBy(u.Id) chọn user Id nhỏ hơn (deterministic).
+            var id2 = await handler.Handle(BuildCmd(), CancellationToken.None);
+            var t2 = await db.ItTickets.FirstAsync(t => t.Id == id2);
+
+            var expectedTieWinner = staffA.Id.CompareTo(staffB.Id) < 0 ? staffA : staffB;
+            t2.AssignedToUserId.Should().Be(expectedTieWinner.Id,
+                "A=1,B=1 tie → ThenBy(u.Id) → user có Guid Id nhỏ hơn");
+        }
+    }
+
+    // ============ Case 2a: Không có Department "IT" → unassigned ============
+
+    [Fact]
+    public async Task CreateItTicket_NoItDepartment_LeavesUnassigned()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            // Chỉ có phòng khác (HR), KHÔNG có Code=="IT".
+            var hrDeptId = await SeedDeptAsync(db, "HR", "Phòng Nhân sự");
+            var requester = await fix.CreateUserAsync("req-rr2@test.local", "Người tạo", null, Array.Empty<string>());
+            await fix.CreateUserAsync("hr-1@test.local", "HR Staff", hrDeptId, Array.Empty<string>());
+
+            var handler = new CreateItTicketHandler(db, AsUser(requester), clock);
+            var id = await handler.Handle(BuildCmd(), CancellationToken.None);
+
+            var t = await db.ItTickets.FirstAsync(t => t.Id == id);
+            t.AssignedToUserId.Should().BeNull("không có Department.Code==\"IT\" → bỏ qua round-robin");
+            t.AssignedToFullName.Should().BeNull();
+        }
+    }
+
+    // ============ Case 2b: Có dept IT nhưng 0 user active trong đó → unassigned ============
+
+    [Fact]
+    public async Task CreateItTicket_ItDepartmentButNoActiveStaff_LeavesUnassigned()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var itDeptId = await SeedDeptAsync(db, "IT", "Phòng CNTT");
+            var requester = await fix.CreateUserAsync("req-rr3@test.local", "Người tạo", null, Array.Empty<string>());
+            // Không seed user nào thuộc IT dept.
+
+            var handler = new CreateItTicketHandler(db, AsUser(requester), clock);
+            var id = await handler.Handle(BuildCmd(), CancellationToken.None);
+
+            var t = await db.ItTickets.FirstAsync(t => t.Id == id);
+            t.AssignedToUserId.Should().BeNull("dept IT tồn tại nhưng 0 user → assignee null");
+        }
+    }
+
+    // ============ Case 3: User ngoài IT / inactive KHÔNG được assign ============
+
+    [Fact]
+    public async Task CreateItTicket_OnlyAssignsActiveStaffInsideItDepartment()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var itDeptId = await SeedDeptAsync(db, "IT", "Phòng CNTT");
+            var otherDeptId = await SeedDeptAsync(db, "FIN", "Phòng Tài chính");
+            var requester = await fix.CreateUserAsync("req-rr4@test.local", "Người tạo", null, Array.Empty<string>());
+
+            // (a) user phòng khác — KHÔNG đủ điều kiện.
+            await fix.CreateUserAsync("fin-1@test.local", "Finance Staff", otherDeptId, Array.Empty<string>());
+            // (b) user IT nhưng IsActive=false — KHÔNG đủ điều kiện.
+            var inactiveIt = await fix.CreateUserAsync("it-off@test.local", "IT Inactive", itDeptId, Array.Empty<string>());
+            inactiveIt.IsActive = false;
+            await db.SaveChangesAsync(CancellationToken.None);
+            // (c) đúng 1 IT staff active — phải là người duy nhất được assign.
+            var activeIt = await fix.CreateUserAsync("it-on@test.local", "IT Active", itDeptId, Array.Empty<string>());
+
+            var handler = new CreateItTicketHandler(db, AsUser(requester), clock);
+            var id = await handler.Handle(BuildCmd(), CancellationToken.None);
+
+            var t = await db.ItTickets.FirstAsync(t => t.Id == id);
+            t.AssignedToUserId.Should().Be(activeIt.Id,
+                "chỉ user IsActive thuộc đúng dept IT mới vào pool round-robin");
+        }
+    }
+
+    // ============ Case 4: SLA-due = CreatedAt + window theo Priority ============
+
+    [Theory]
+    [InlineData(4, 4)]    // Urgent → +4h
+    [InlineData(3, 8)]    // High   → +8h
+    [InlineData(2, 24)]   // Medium → +24h
+    [InlineData(1, 72)]   // Low    → +72h
+    public async Task CreateItTicket_SlaDueAt_MatchesPriorityWindow(int priority, int expectedHours)
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            var requester = await fix.CreateUserAsync($"req-sla{priority}@test.local", "Người tạo", null, Array.Empty<string>());
+
+            var handler = new CreateItTicketHandler(db, AsUser(requester), clock);
+            var id = await handler.Handle(BuildCmd(priority), CancellationToken.None);
+
+            var t = await db.ItTickets.FirstAsync(t => t.Id == id);
+            t.CreatedAt.Should().Be(FixedNow, "clock stub cố định → CreatedAt = clock.UtcNow");
+            t.SlaDueAt.Should().Be(FixedNow.AddHours(expectedHours),
+                $"Priority {priority} → SLA window {expectedHours}h từ CreatedAt");
+            t.SlaBreached.Should().BeFalse("ticket mới chưa breach");
+            t.SlaWarnedSent.Should().BeFalse("ticket mới chưa cảnh báo");
+        }
+    }
+
+    // ============ Case 5: Regression P11-F — MaTicket vẫn gen đúng format ============
+
+    [Fact]
+    public async Task CreateItTicket_StillGeneratesMaTicket_FormatUnchanged()
+    {
+        var (fix, db, clock) = NewCtx();
+        using (fix)
+        {
+            // Có dept IT + staff để chạy luôn nhánh round-robin → đảm bảo codegen
+            // vẫn chạy chung với assign logic, không bị nhánh mới phá format.
+            var itDeptId = await SeedDeptAsync(db, "IT", "Phòng CNTT");
+            await fix.CreateUserAsync("it-reg@test.local", "IT Staff", itDeptId, Array.Empty<string>());
+            var requester = await fix.CreateUserAsync("req-reg@test.local", "Người tạo", null, Array.Empty<string>());
+
+            var handler = new CreateItTicketHandler(db, AsUser(requester), clock);
+            var id = await handler.Handle(BuildCmd(), CancellationToken.None);
+
+            var t = await db.ItTickets.FirstAsync(t => t.Id == id);
+            t.MaTicket.Should().NotBeNullOrEmpty();
+            t.MaTicket.Should().MatchRegex(@"^IT/\d{4}/\d{3}$", "P11-D đổi handler nhưng codegen P11-F giữ format");
+            t.MaTicket.Should().Be("IT/2026/001", "vẫn seq đầu năm 2026");
+        }
+    }
+}