Add region code

Distribution/Migrations/AppDBContextModelSnapshot.cs

@@ -1474,6 +1474,11 @@ namespace Distribution.Migrations
                         .ValueGeneratedOnAdd()
                         .HasColumnType("char(36)");
 
+                    b.Property<string>("Code")
+                        .IsRequired()
+                        .HasMaxLength(50)
+                        .HasColumnType("varchar(50)");
+
                     b.Property<DateTime>("CreatedAt")
                         .HasColumnType("datetime(6)");
 
@@ -1486,6 +1491,9 @@ namespace Distribution.Migrations
 
                     b.HasKey("Id");
 
+                    b.HasIndex("Code")
+                        .IsUnique();
+
                     b.ToTable("Regions");
 
                     b.HasData(
@@ -1494,6 +1502,7 @@ namespace Distribution.Migrations
                             Id = new Guid("24000000-0000-0000-0000-000000000001"),
                             CreatedAt = new DateTime(2026, 8, 20, 0, 0, 0, 0, DateTimeKind.Unspecified),
                             IsActive = true,
+                            Code = "REG-0001",
                             Name = "Western Province"
                         },
                         new
@@ -1501,6 +1510,7 @@ namespace Distribution.Migrations
                             Id = new Guid("24000000-0000-0000-0000-000000000002"),
                             CreatedAt = new DateTime(2026, 8, 20, 0, 0, 0, 0, DateTimeKind.Unspecified),
                             IsActive = true,
+                            Code = "REG-0002",
                             Name = "Central Province"
                         });
                 });