feat(battle-node): Gungnir alive-body builders (scs/ocs ONLINE placeholders)

SVSim.UnitTests/BattleNode/Reliability/GungnirTests.cs

@@ -0,0 +1,28 @@
+using NUnit.Framework;
+using SVSim.BattleNode.Reliability;
+
+namespace SVSim.UnitTests.BattleNode.Reliability;
+
+[TestFixture]
+public class GungnirTests
+{
+    [Test]
+    public void BuildAlivePush_AlwaysReturnsScsOnlineOcsOnline()
+    {
+        var body = Gungnir.BuildAlivePushBody();
+        Assert.That(body["scs"], Is.EqualTo("ONLINE"));
+        Assert.That(body["ocs"], Is.EqualTo("ONLINE"));
+    }
+
+    [Test]
+    public void BuildAliveEmit_CarriesCurrentSeqFromTracker()
+    {
+        var tracker = new InboundTracker();
+        tracker.Observe(7);
+
+        var body = Gungnir.BuildAliveEmitBody(tracker);
+
+        Assert.That(body["currentSeq"], Is.EqualTo(7L));
+        Assert.That(body.ContainsKey("actionSeq"), Is.False);  // omitted in v1
+    }
+}