feat(config): migration AddClusterNodeTransportPorts

Additive only — two AddColumn ops, no AlterColumn, so no accumulated model
drift is riding along with this change:

  ALTER TABLE [ClusterNode] ADD [AkkaPort] int NOT NULL DEFAULT 4053;
  ALTER TABLE [ClusterNode] ADD [GrpcPort] int NULL;

Adds a third test covering the DB-side default specifically. The entity
round-trip cannot see it: ClusterNode.AkkaPort's CLR initializer is also 4053,
so that assertion passes with the mapping default deleted. The new test inserts
through raw SQL with the column omitted, so only the schema can supply the
value — verified by setting defaultValue: 0, which turns exactly that one test
red and leaves the other two green.

Configuration.Tests 95/95.

Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW

src/Core/ZB.MOM.WW.OtOpcUa.Configuration/Migrations/OtOpcUaConfigDbContextModelSnapshot.cs

@@ -47,6 +47,11 @@ namespace ZB.MOM.WW.OtOpcUa.Configuration.Migrations
                         .HasMaxLength(64)
                         .HasColumnType("nvarchar(64)");
 
+                    b.Property<int>("AkkaPort")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("int")
+                        .HasDefaultValue(4053);
+
                     b.Property<string>("ApplicationUri")
                         .IsRequired()
                         .HasMaxLength(256)
@@ -76,6 +81,9 @@ namespace ZB.MOM.WW.OtOpcUa.Configuration.Migrations
                     b.Property<bool>("Enabled")
                         .HasColumnType("bit");
 
+                    b.Property<int?>("GrpcPort")
+                        .HasColumnType("int");
+
                     b.Property<string>("Host")
                         .IsRequired()
                         .HasMaxLength(255)