fix(battlenode): EngineGlobalInit guarantees full-master postcondition (Phase 2 N2 review)

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

SVSim.BattleEngine.Tests/SessionEngine/SessionEngineSpellboostTests.cs

@@ -1,6 +1,7 @@
 using NUnit.Framework;
 using SVSim.BattleNode.Sessions.Engine;
 using System.Linq;
+using SVSim.BattleEngine.Tests;
 
 namespace SVSim.BattleEngine.Tests.SessionEngine;
 
@@ -15,6 +16,10 @@ public class SessionEngineSpellboostTests
         var cl2 = CaptureReplay.Load("battle_test_cl2.ndjson");
         var deckA = CaptureReplay.SelfDeckFrom(cl1);
         var deckB = CaptureReplay.SelfDeckFrom(cl2);
+        // Belt-and-suspenders (matches the sibling tests): load the decks into the harness master so
+        // this test never depends on global card-master contents. EnsureInitialized() above still
+        // proves EngineGlobalInit's own path works.
+        foreach (var id in deckA.Concat(deckB).Distinct()) HeadlessCardMaster.Load((int)id);
         var engine = new SessionBattleEngine();
         Assert.DoesNotThrow(() => engine.Setup(masterSeed: 12345, seatADeck: deckA, seatBDeck: deckB));
         Assert.That(engine.IsReady, Is.True, "engine must be ready after EngineGlobalInit (carried-risk fix)");