feat(battle-node): JudgeHandler emits {spin:0} to opponent in PvP

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

SVSim.BattleNode/Sessions/Dispatch/Handlers/JudgeHandler.cs

@@ -1,4 +1,5 @@
 using SVSim.BattleNode.Protocol;
+using SVSim.BattleNode.Protocol.Bodies;
 
 namespace SVSim.BattleNode.Sessions.Dispatch.Handlers;
 
@@ -6,9 +7,18 @@ internal sealed class JudgeHandler : IFrameHandler
 {
     public IReadOnlyList<DispatchRoute> Handle(FrameDispatchContext ctx)
     {
-        // Only a scripted-bot Judge is forwarded. A real player's Judge has no routing rule (drops).
+        // Scripted-bot Judge (test stub): forward verbatim (carries the {spin} shape already).
         if (ctx.IsScriptedBot(ctx.From))
             return new[] { new DispatchRoute(ctx.Other, ctx.Env, false) };
+
+        // PvP: active player's Judge{battleCode} -> opponent {spin} (RNG catch-up; spin=0 for the
+        // deterministic-turn slice). Receiving Judge starts the opponent's own turn.
+        if (ctx.Type == BattleType.Pvp && ctx.BothAfterReady())
+        {
+            var frame = ctx.Env with { Body = new JudgeBody(Spin: 0) };
+            return new[] { new DispatchRoute(ctx.Other, frame, false) };
+        }
+
         return Array.Empty<DispatchRoute>();
     }
 }

SVSim.UnitTests/BattleNode/Sessions/BattleSessionDispatchTests.cs

@@ -399,6 +399,22 @@ public class BattleSessionDispatchTests
         Assert.That(body.Spin, Is.EqualTo(0));
     }
 
+    [Test]
+    public void Pvp_Judge_from_A_emits_spin0_to_B()
+    {
+        var (s, a, b) = NewPvpSession();
+        DriveToAfterReady(s, a);
+        DriveToAfterReady(s, b);
+
+        var routes = s.ComputeFrames(a, NewEnvelope(NetworkBattleUri.Judge));
+
+        Assert.That(routes.Count, Is.EqualTo(1));
+        Assert.That(routes[0].Target, Is.SameAs(b));
+        Assert.That(routes[0].Frame.Uri, Is.EqualTo(NetworkBattleUri.Judge));
+        var body = (SVSim.BattleNode.Protocol.Bodies.JudgeBody)routes[0].Frame.Body;
+        Assert.That(body.Spin, Is.EqualTo(0));
+    }
+
     [Test]
     public void Pvp_PlayActions_synthesizes_knownList_from_sender_deck()
     {