test: Campaign LA finish LA2 probe and idle gates

Prove idle play remains passive and live until cancellation, then converges through one truthful status teardown. Keep probe mode string-only so numeric enum aliases cannot expand the pinned v1 contract, and record the Windows/WSL gates.

tests/AcDream.Headless.Tests/HeadlessBotPolicyTests.cs

@@ -0,0 +1,77 @@
+using System.Reflection;
+using AcDream.Headless.Policies;
+using AcDream.Runtime;
+
+namespace AcDream.Headless.Tests;
+
+public sealed class HeadlessBotPolicyTests
+{
+    /// <summary>
+    /// Campaign LA slice LA2: <c>idle</c> is a deliberately passive,
+    /// non-terminal policy. It must neither inspect Runtime state nor reach
+    /// any command surface, and no event can make it complete on its own.
+    /// The process scheduler therefore keeps the play session alive until
+    /// external cancellation/stop drives the host's ordinary teardown path.
+    /// </summary>
+    [Fact]
+    public void IdlePolicyIsPassiveAndNeverCompletesAutonomously()
+    {
+        var policy = new IdleHeadlessBotPolicy();
+        IGameRuntimeView view = CreateNoTouchProxy<IGameRuntimeView>(
+            out InvocationCountingProxy viewCalls);
+        IGameRuntimeCommands commands =
+            CreateNoTouchProxy<IGameRuntimeCommands>(
+                out InvocationCountingProxy commandCalls);
+
+        for (int index = 0; index < 3; index++)
+            policy.Tick(view, commands);
+
+        RuntimeLifecycleDelta lifecycle = default;
+        RuntimeCommandDelta command = default;
+        RuntimeEntityDelta entity = default;
+        RuntimeInventoryDelta inventory = default;
+        RuntimeChatDelta chat = default;
+        RuntimeMovementDelta movement = default;
+        RuntimePortalDelta portal = default;
+        RuntimeCombatDelta combat = default;
+        policy.OnLifecycle(in lifecycle);
+        policy.OnCommand(in command);
+        policy.OnEntity(in entity);
+        policy.OnInventory(in inventory);
+        policy.OnChat(in chat);
+        policy.OnMovement(in movement);
+        policy.OnPortal(in portal);
+        policy.OnCombat(in combat);
+
+        Assert.False(policy.IsComplete);
+        Assert.Equal(0, viewCalls.InvocationCount);
+        Assert.Equal(0, commandCalls.InvocationCount);
+
+        policy.Dispose();
+        policy.Dispose();
+        Assert.False(policy.IsComplete);
+    }
+
+    private static T CreateNoTouchProxy<T>(
+        out InvocationCountingProxy proxy)
+        where T : class
+    {
+        T value = DispatchProxy.Create<T, InvocationCountingProxy>();
+        proxy = (InvocationCountingProxy)(object)value;
+        return value;
+    }
+
+    public class InvocationCountingProxy : DispatchProxy
+    {
+        public int InvocationCount { get; private set; }
+
+        protected override object? Invoke(
+            MethodInfo? targetMethod,
+            object?[]? args)
+        {
+            InvocationCount++;
+            throw new InvalidOperationException(
+                $"Idle policy unexpectedly invoked {targetMethod?.Name}.");
+        }
+    }
+}