feat(battle-node): client-shaped handshake builders for the scripted bot

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

SVSim.BattleNode/Lifecycle/ScriptedLifecycle.cs

@@ -127,6 +127,37 @@ public static class ScriptedLifecycle
                 IdxChangeSeed: ScriptedProfiles.ReadyIdxChangeSeed,
                 Spin: ScriptedProfiles.ReadySpin));
 
+    // --- Client-shaped emissions used by ScriptedBotParticipant so the session brokers
+    // the bot through the same handshake arms as a human. Bodies for the parameterless
+    // handshake frames are ignored by the session (it reads from.Context / phase); only
+    // Swap's idxList is consumed (empty = keep the dealt hand).
+
+    public static MsgEnvelope BuildClientInitNetwork() => ClientFrame(NetworkBattleUri.InitNetwork, EmitCategory.General);
+    public static MsgEnvelope BuildClientInitBattle() => ClientFrame(NetworkBattleUri.InitBattle, EmitCategory.General);
+    public static MsgEnvelope BuildClientLoaded() => ClientFrame(NetworkBattleUri.Loaded, EmitCategory.General);
+
+    public static MsgEnvelope BuildClientSwap() =>
+        new(NetworkBattleUri.Swap,
+            ViewerId: FakeOpponentViewerId,
+            Uuid: WireConstants.ServerUuid,
+            Bid: null,
+            Try: 0,
+            Cat: EmitCategory.Battle,
+            PubSeq: null,
+            PlaySeq: null,
+            Body: new RawBody(new Dictionary<string, object?> { ["idxList"] = new List<object?>() }));
+
+    private static MsgEnvelope ClientFrame(NetworkBattleUri uri, EmitCategory cat) =>
+        new(uri,
+            ViewerId: FakeOpponentViewerId,
+            Uuid: WireConstants.ServerUuid,
+            Bid: null,
+            Try: 0,
+            Cat: cat,
+            PubSeq: null,
+            PlaySeq: null,
+            Body: new ResultCodeOnlyBody());
+
     /// <summary>
     /// First half of the v1.1 scripted opponent turn cycle: pushed after the player's
     /// TurnEnd, transitions the client into "Opponent's turn…" state. Paired with

SVSim.UnitTests/BattleNode/Lifecycle/ScriptedLifecycleTests.cs

@@ -166,6 +166,27 @@ public class ScriptedLifecycleTests
             "single-arg overload (non-interactive opponent) keeps the placeholder hand.");
     }
 
+    [Test]
+    public void BuildClientSwap_has_empty_idxList_in_RawBody()
+    {
+        var env = ScriptedLifecycle.BuildClientSwap();
+        Assert.That(env.Uri, Is.EqualTo(NetworkBattleUri.Swap));
+        Assert.That(env.ViewerId, Is.EqualTo(ScriptedLifecycle.FakeOpponentViewerId));
+
+        var raw = (RawBody)env.Body;
+        Assert.That(raw.Entries.ContainsKey("idxList"), Is.True);
+        var idx = (System.Collections.IEnumerable)raw.Entries["idxList"]!;
+        Assert.That(idx.Cast<object>().Count(), Is.EqualTo(0), "bot keeps its dealt hand (empty mulligan).");
+    }
+
+    [Test]
+    public void BuildClientHandshakeFrames_carry_expected_uris()
+    {
+        Assert.That(ScriptedLifecycle.BuildClientInitNetwork().Uri, Is.EqualTo(NetworkBattleUri.InitNetwork));
+        Assert.That(ScriptedLifecycle.BuildClientInitBattle().Uri, Is.EqualTo(NetworkBattleUri.InitBattle));
+        Assert.That(ScriptedLifecycle.BuildClientLoaded().Uri, Is.EqualTo(NetworkBattleUri.Loaded));
+    }
+
     [Test]
     public void BuildOpponentTurnStart_HasUriTurnStartAndSpin()
     {