[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.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");