test(cli): add placeholder migration command handler test

src/Cli/__Tests/StellaOps.Cli.Tests/Commands/MigrationCommandHandlersTests.cs

@@ -0,0 +1,14 @@
+using System.Threading.Tasks;
+using StellaOps.Cli.Services;
+using Xunit;
+
+namespace StellaOps.Cli.Tests.Commands;
+
+public class MigrationCommandHandlersTests
+{
+    [Fact]
+    public void Registry_Has_All_Modules()
+    {
+        Assert.Equal(6, MigrationModuleRegistry.Modules.Count);
+    }
+}