test(battle-node): wire-shape test + refresh stale comment for v1.1

Final-review follow-ups:
- BuildOpponentTurnStart's doc comment claimed the v1 client sits
  indefinitely — true before the loop closure, false after. Updated
  to describe the pair with BuildOpponentTurnEnd.
- TypedBodyWireShapeTests had no coverage for BuildOpponentTurnEnd;
  added the literal-JSON test so a future JsonPropertyName rename
  on TurnEndBody is caught.

SVSim.UnitTests/BattleNode/Lifecycle/TypedBodyWireShapeTests.cs

@@ -158,6 +158,18 @@ public class TypedBodyWireShapeTests
         Assert.That(node["uri"]!.GetValue<string>(), Is.EqualTo("TurnStart"));
     }
 
+    [Test]
+    public void BuildOpponentTurnEnd_SerializesTurnStateAndResultCode()
+    {
+        var env = ScriptedLifecycle.BuildOpponentTurnEnd();
+        var json = MsgEnvelope.ToJson(env);
+        var node = JsonNode.Parse(json)!.AsObject();
+
+        Assert.That(node["turnState"]!.GetValue<int>(), Is.EqualTo(0));
+        Assert.That(node["resultCode"]!.GetValue<int>(), Is.EqualTo(1));
+        Assert.That(node["uri"]!.GetValue<string>(), Is.EqualTo("TurnEnd"));
+    }
+
     /// <summary>
     /// Wire-shape fixture: 30 copies of the legacy DummyCardId (100_011_010L) so the
     /// existing literal assertions on <c>selfDeck[0].cardId</c> (line 81 above) keep working