SignatureTests: the one-view check fails by assertion, not by a test-host abort (Assert.Same formatted the entity graph)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/Aetheria.Shared.Tests/SignatureTests.cs

@@ -432,7 +432,7 @@ public sealed class SignatureTests : IDisposable
         var r = Build(Armament.None, 0f, null);
         var view = r.Ship.VisibilitySources;
         Assert.False(view is Dictionary<object, Signature>);
-        Assert.Same(view, r.Ship.VisibilitySources);
+        Assert.True(ReferenceEquals(view, r.Ship.VisibilitySources), "one view object per entity"); // not Assert.Same: its failure message formats the entity graph and aborts the test host
         Assert.Throws<NotSupportedException>(() => ((IDictionary<object, Signature>) view)[r.Ship] = new Signature(SignatureChannel.Thermal, 1f, null));
     }