test(battlenode): node-native battle harness for headless conductor (M-HC-0)

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

SVSim.UnitTests/BattleNode/Integration/HeadlessConductorTests.cs

@@ -0,0 +1,33 @@
+using NUnit.Framework;
+
+namespace SVSim.UnitTests.BattleNode.Integration;
+
+/// <summary>
+/// Headless-Conductor milestone tests (M-HC-*). The oracle is a node-native battle:
+/// a FIXED master seed + FIXED decks drive the engine's receive path headless, and we
+/// assert on engine board-state. By construction the node assigns idx = position in the
+/// shuffled order, so the engine's headless draw reproduces the node's draw order.
+///
+/// Task 1 (M-HC-0a) exit criterion: the engine seats headless (IsReady) in the
+/// SVSim.UnitTests process.
+/// </summary>
+[TestFixture]
+public class HeadlessConductorTests
+{
+    [Test]
+    public void Harness_seats_engine_headless_and_is_ready()
+    {
+        using var harness = NodeNativeBattleHarness.Create();
+
+        Assert.That(harness.IsReady, Is.True,
+            "Engine must seat headless: EngineGlobalInit ran + both decks seeded. " +
+            "If false, the most likely cause is a missing cards.json content link in " +
+            "SVSim.UnitTests.csproj (EngineGlobalInit reads AppContext.BaseDirectory/Data/cards.json).");
+
+        // Non-vacuous: a seated engine has live board state for BOTH seats. Reading these off a
+        // not-really-set-up engine would throw (Seat() guards on _mgr). Leader life is the headless
+        // default (20) before any frame is ingested.
+        Assert.That(harness.LeaderLife(playerSeat: true), Is.EqualTo(20), "seat A leader life");
+        Assert.That(harness.LeaderLife(playerSeat: false), Is.EqualTo(20), "seat B leader life");
+    }
+}