fix(combat): synchronize auto-target presentation

Make the retained toolbar consume retail's payload-free selection notice from canonical live state so a reentrant Auto Target replacement cannot be erased by the outer clear. Restrict automatic acquisition to the requested hostile non-player monster policy and record the intentional PK edge divergence.

Co-Authored-By: Codex <codex@openai.com>

tests/AcDream.App.Tests/UI/Layout/SelectedObjectControllerTests.cs

@@ -171,6 +171,38 @@ public class SelectedObjectControllerTests
         Assert.Empty(textChild.LinesProvider());
     }
 
+    [Fact]
+    public void ReentrantAutoTargetNotice_RendersCurrentReplacementNotStaleClear()
+    {
+        const uint Dead = 0xAA00u;
+        const uint Replacement = 0xAA01u;
+        var (layout, nameEl, _, _) = FakeLayout();
+        var h = new Harness();
+        h.NameMap[Dead] = "Dead Drudge";
+        h.NameMap[Replacement] = "Drudge Prowler";
+        h.StackMap[Dead] = 1u;
+        h.StackMap[Replacement] = 1u;
+
+        h.Selection.Select(Dead, SelectionChangeSource.World);
+        // CombatTargetController is registered before the retained toolbar in
+        // production. Its clear handler selects a replacement reentrantly.
+        h.Selection.Changed += transition =>
+        {
+            if (transition.SelectedObjectId is null)
+                h.Selection.Select(Replacement, SelectionChangeSource.System);
+        };
+        h.Bind(layout);
+
+        h.Selection.Clear(
+            SelectionChangeSource.System,
+            SelectionChangeReason.CombatTargetDied);
+
+        Assert.Equal(Replacement, h.Selection.SelectedObjectId);
+        var lines = nameEl.Children.OfType<UiText>().Single().LinesProvider();
+        Assert.Single(lines);
+        Assert.Equal("Drudge Prowler", lines[0].Text);
+    }
+
     // ── H1: Select a health target — meter does NOT show on select alone ─────
 
     [Fact]

tests/AcDream.Core.Tests/Combat/CombatTargetPolicyTests.cs

@@ -0,0 +1,46 @@
+using AcDream.Core.Combat;
+using AcDream.Core.Items;
+
+namespace AcDream.Core.Tests.Combat;
+
+public sealed class CombatTargetPolicyTests
+{
+    private const uint PlayerId = 0x50000001u;
+
+    private static ClientObject Creature(
+        uint id,
+        uint flags = 0,
+        uint petOwner = 0) => new()
+    {
+        ObjectId = id,
+        Type = ItemType.Creature,
+        PublicWeenieBitfield = flags,
+        PetOwnerId = petOwner,
+    };
+
+    [Fact]
+    public void AutomaticAcquisition_AcceptsOnlyAttackableNonPlayerMonster()
+    {
+        var player = Creature(PlayerId, SelectedObjectHealthPolicy.BfPlayer);
+        var monster = Creature(0x50000010u, SelectedObjectHealthPolicy.BfAttackable);
+        var friendlyNpc = Creature(0x50000011u);
+        var pet = Creature(0x50000012u, petOwner: PlayerId);
+        var hostilePlayer = Creature(
+            0x50000013u,
+            SelectedObjectHealthPolicy.BfPlayer
+                | SelectedObjectHealthPolicy.BfPlayerKiller);
+        player.PublicWeenieBitfield |= SelectedObjectHealthPolicy.BfPlayerKiller;
+        var attackableDoor = new ClientObject
+        {
+            ObjectId = 0x50000014u,
+            Type = ItemType.Misc,
+            PublicWeenieBitfield = SelectedObjectHealthPolicy.BfAttackable,
+        };
+
+        Assert.True(CombatTargetPolicy.IsHostileMonster(PlayerId, player, monster));
+        Assert.False(CombatTargetPolicy.IsHostileMonster(PlayerId, player, friendlyNpc));
+        Assert.False(CombatTargetPolicy.IsHostileMonster(PlayerId, player, pet));
+        Assert.False(CombatTargetPolicy.IsHostileMonster(PlayerId, player, hostilePlayer));
+        Assert.False(CombatTargetPolicy.IsHostileMonster(PlayerId, player, attackableDoor));
+    }
+}