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>

src/AcDream.App/Rendering/GameWindow.cs

@@ -11964,7 +11964,7 @@ public sealed class GameWindow : IDisposable
 
     private uint? GetSelectedOrClosestCombatTarget()
     {
-        if (_selection.SelectedObjectId is { } selected && IsLiveCreatureTarget(selected))
+        if (_selection.SelectedObjectId is { } selected && IsLiveHostileMonsterTarget(selected))
             return selected;
 
         if (!_persistedGameplay.AutoTarget)
@@ -11984,7 +11984,7 @@ public sealed class GameWindow : IDisposable
         if (!_persistedGameplay.ViewCombatTarget
             || !AcDream.Core.Combat.CombatInputPlanner.SupportsTargetedAttack(Combat.CurrentMode)
             || _selection.SelectedObjectId is not uint selected
-            || !IsLiveCreatureTarget(selected)
+            || !IsLiveHostileMonsterTarget(selected)
             || !_entitiesByServerGuid.TryGetValue(selected, out var target))
             return null;
 
@@ -12496,7 +12496,7 @@ public sealed class GameWindow : IDisposable
         float bestDistanceSq = float.PositiveInfinity;
         foreach (var (guid, entity) in _entitiesByServerGuid)
         {
-            if (!IsLiveCreatureTarget(guid))
+            if (!IsLiveHostileMonsterTarget(guid))
                 continue;
 
             float distanceSq = System.Numerics.Vector3.DistanceSquared(
@@ -12545,6 +12545,17 @@ public sealed class GameWindow : IDisposable
         return (LiveItemType(guid) & AcDream.Core.Items.ItemType.Creature) != 0;
     }
 
+    private bool IsLiveHostileMonsterTarget(uint guid)
+    {
+        if (!IsLiveCreatureTarget(guid))
+            return false;
+
+        return AcDream.Core.Combat.CombatTargetPolicy.IsHostileMonster(
+            _playerServerGuid,
+            Objects.Get(_playerServerGuid),
+            Objects.Get(guid));
+    }
+
     /// <summary>
     /// True if the selected-object strip should show a Health meter for <paramref name="guid"/>.
     /// Exact projection of retail's <c>IsPlayer() || pet_owner ||

src/AcDream.App/UI/Layout/SelectedObjectController.cs

@@ -437,7 +437,16 @@ public sealed class SelectedObjectController : IRetainedPanelController
     }
 
     private void OnSelectionTransition(SelectionTransition transition)
-        => ApplySelection(transition.SelectedObjectId);
+    {
+        // Retail's CM_UI::SendNotice_SelectionChanged (0x00479F50) carries no
+        // selected-id payload. gmToolbarUI::HandleSelectionChanged therefore
+        // reads the live ACCWeenieObject::selectedID when its notice handler
+        // runs. This matters when an earlier handler (ClientCombatSystem::
+        // AutoTarget) selects a replacement reentrantly: the outer "cleared"
+        // notice must render that replacement, not stale transition data.
+        _ = transition;
+        ApplySelection(_selection.SelectedObjectId);
+    }
 
     public void Dispose()
     {

src/AcDream.Core/Combat/CombatTargetPolicy.cs

@@ -0,0 +1,42 @@
+using AcDream.Core.Items;
+
+namespace AcDream.Core.Combat;
+
+/// <summary>
+/// Eligibility policy for automatic monster acquisition.
+/// </summary>
+public static class CombatTargetPolicy
+{
+    /// <summary>
+    /// Returns true only for a live-data creature that is attackable, is not a
+    /// player, and is not a pet. Friendly NPCs and non-creatures are rejected.
+    /// </summary>
+    /// <remarks>
+    /// The attackability core is retail
+    /// <c>ClientCombatSystem::ObjectIsAttackable @ 0x0056A600</c>. Retail
+    /// <c>AutoTarget @ 0x0056BC80</c> falls back to
+    /// <c>SelectNext(SELECTION_TYPE_COMPASS_ITEM)</c>, whose combat filter also
+    /// uses ObjectIsAttackable. acdream deliberately narrows that set to
+    /// non-player monsters for its automatic acquisition policy; explicit
+    /// player-selection commands remain separate.
+    /// </remarks>
+    public static bool IsHostileMonster(
+        uint playerId,
+        ClientObject? player,
+        ClientObject? candidate)
+    {
+        if (candidate is null
+            || candidate.ObjectId == playerId
+            || (candidate.Type & ItemType.Creature) == 0
+            || (candidate.PublicWeenieBitfield.GetValueOrDefault()
+                & SelectedObjectHealthPolicy.BfPlayer) != 0
+            || candidate.PetOwnerId != 0)
+            return false;
+
+        return SelectedObjectHealthPolicy.ObjectIsAttackable(
+            playerId,
+            player,
+            candidate.ObjectId,
+            candidate);
+    }
+}