[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>

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)
 // =========================================================================