fix(ui): port exact selected health policy

Replace the toolbar's PWD-bit approximation with retail ObjectIsAttackable composed with the exact player and pet short-circuits. Carry second-header PetOwner through CreateObject, session, and ClientObject state so self, pet, and Free-PK cases match retail while friendly NPCs and attackable non-creatures remain name-only.

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

src/AcDream.Core/Combat/SelectedObjectHealthPolicy.cs

@@ -0,0 +1,79 @@
+using AcDream.Core.Items;
+
+namespace AcDream.Core.Combat;
+
+/// <summary>
+/// Retail selected-object health-query eligibility.
+/// Ports <c>gmToolbarUI::HandleSelectionChanged @ 0x004BF380</c> and
+/// <c>ClientCombatSystem::ObjectIsAttackable @ 0x0056A600</c>.
+/// </summary>
+public static class SelectedObjectHealthPolicy
+{
+    public const uint BfPlayer = 0x00000008u;
+    public const uint BfAttackable = 0x00000010u;
+    public const uint BfPlayerKiller = 0x00000020u;
+    public const uint BfFreePkStatus = 0x00200000u;
+    public const uint BfPkLiteStatus = 0x02000000u;
+
+    /// <summary>
+    /// Exact toolbar composition: every player, every pet, otherwise retail's
+    /// reusable combat attackability predicate. Stacked objects take the separate
+    /// split-control branch before this policy is called.
+    /// </summary>
+    public static bool ShouldQueryHealth(
+        uint playerId,
+        ClientObject? player,
+        ClientObject? selected)
+    {
+        if (selected is null)
+            return false;
+
+        uint flags = selected.PublicWeenieBitfield ?? 0u;
+        return (flags & BfPlayer) != 0
+            || selected.PetOwnerId != 0
+            || ObjectIsAttackable(playerId, player, selected.ObjectId, selected);
+    }
+
+    /// <summary>
+    /// Line-for-line branch port of
+    /// <c>ClientCombatSystem::ObjectIsAttackable @ 0x0056A600</c>.
+    /// </summary>
+    public static bool ObjectIsAttackable(
+        uint playerId,
+        ClientObject? player,
+        uint targetId,
+        ClientObject? target)
+    {
+        if (targetId == 0 || targetId == playerId)
+            return true;
+
+        if (target is null || (target.Type & ItemType.Creature) == 0)
+            return false;
+
+        uint targetFlags = target.PublicWeenieBitfield ?? 0u;
+        if ((targetFlags & BfFreePkStatus) != 0)
+            return true;
+
+        if (player is null)
+            return false;
+
+        uint playerFlags = player.PublicWeenieBitfield ?? 0u;
+        if ((playerFlags & BfFreePkStatus) != 0)
+            return true;
+
+        if ((targetFlags & BfPlayer) != 0)
+        {
+            if ((targetFlags & BfPlayerKiller) != 0
+                && (playerFlags & BfPlayerKiller) != 0)
+                return true;
+
+            return (targetFlags & BfPkLiteStatus) != 0
+                && (playerFlags & BfPkLiteStatus) != 0;
+        }
+
+        if (target.PetOwnerId != 0)
+            return false;
+
+        return (targetFlags & BfAttackable) != 0;
+    }
+}

src/AcDream.Core/Items/ClientObject.cs

@@ -182,6 +182,11 @@ public sealed class ClientObject
     public uint? TargetType  { get; set; }    // ITEM_TYPE mask for targeted-use compatibility
     /// <summary>Retail <c>PublicWeenieDesc._bitfield</c>; null until CreateObject supplies it.</summary>
     public uint? PublicWeenieBitfield { get; set; }
+    /// <summary>
+    /// Retail <c>PublicWeenieDesc._pet_owner</c>; zero means this creature is not a pet.
+    /// CreateObject second-header flag <c>PWD2_Packed_PetOwner (0x8)</c> supplies it.
+    /// </summary>
+    public uint PetOwnerId { get; set; }
     /// <summary>Retail <c>PublicWeenieDesc._combatUse</c>; null when its header flag was absent.</summary>
     public byte? CombatUse { get; set; }
     /// <summary>Client-side trade state used by ItemHolder legality gates.</summary>
@@ -249,7 +254,8 @@ public readonly record struct WeenieData(
     byte? RadarBehavior = null,
     uint? PublicWeenieBitfield = null,
     byte? CombatUse = null,
-    string? PluralName = null);
+    string? PluralName = null,
+    uint? PetOwnerId = null);
 
 /// <summary>
 /// Retail ITEM_USEABLE helpers (acclient.h:6478, ItemUses::* at 0x004fccd0).

src/AcDream.Core/Items/ClientObjectTable.cs

@@ -388,6 +388,7 @@ public sealed class ClientObjectTable
         if (d.Useability is { } use) obj.Useability = use;
         if (d.TargetType is { } targetType) obj.TargetType = targetType;
         if (d.PublicWeenieBitfield is { } bitfield) obj.PublicWeenieBitfield = bitfield;
+        if (d.PetOwnerId is { } petOwnerId) obj.PetOwnerId = petOwnerId;
         if (d.CombatUse is { } combatUse) obj.CombatUse = combatUse;
         if (d.RadarBlipColor is { } radarBlipColor) obj.RadarBlipColor = radarBlipColor;
         if (d.RadarBehavior is { } radarBehavior) obj.RadarBehavior = radarBehavior;