fix(items): port retail useability and autowear rejection

Use the exact low USEABLE_NO-bit predicate so reset/zero-valued direct-use items such as Blackmoor's Favor reach the ordinary Use request. Port AutoWear's clothing-priority blocker lookup and exact named system notice through the shared activation owner.

Co-authored-by: Codex <codex@openai.com>

tests/AcDream.App.Tests/Interaction/WorldSelectionQueryTests.cs

@@ -279,6 +279,29 @@ public sealed class WorldSelectionQueryTests
         Assert.True(h.Query.IsPickupable(looseComponent));
     }
 
+    [Fact]
+    public void UseabilityUsesRetailLowNoBitForAbsentAndExplicitValues()
+    {
+        var h = new Harness();
+        const uint absent = 0x7000_0022u;
+        const uint zero = 0x7000_0023u;
+        const uint no = 0x7000_0024u;
+        const uint neverWalk = 0x7000_0025u;
+        h.Add(absent, Vector3.UnitX, ItemType.Gem);
+        h.Add(zero, Vector3.UnitX * 2f, ItemType.Gem, useability: 0u);
+        h.Add(no, Vector3.UnitX * 3f, ItemType.Gem, useability: ItemUseability.No);
+        h.Add(
+            neverWalk,
+            Vector3.UnitX * 4f,
+            ItemType.Gem,
+            useability: ItemUseability.NeverWalk);
+
+        Assert.True(h.Query.IsUseable(absent));
+        Assert.True(h.Query.IsUseable(zero));
+        Assert.False(h.Query.IsUseable(no));
+        Assert.True(h.Query.IsUseable(neverWalk));
+    }
+
     [Fact]
     public void SelectionSphereAppliesSetupOffsetScaleAndRotation()
     {

tests/AcDream.App.Tests/UI/ItemInteractionControllerTests.cs

@@ -436,6 +436,24 @@ public sealed class ItemInteractionControllerTests
         Assert.Equal(new[] { 0x50000A03u }, h.Uses);
     }
 
+    [Fact]
+    public void ZeroValuedUseabilityGem_sendsUseLikeBlackmoorsFavor()
+    {
+        var h = new Harness();
+        const uint favor = 0x50000A30u;
+        h.AddContained(favor, item =>
+        {
+            item.Name = "Blackmoor's Favor";
+            item.Type = ItemType.Gem;
+            item.Useability = ItemUseability.Undef;
+        });
+
+        Assert.True(h.Controller.ActivateItem(favor));
+
+        Assert.Equal(new[] { favor }, h.Uses);
+        Assert.Equal(1, h.Controller.BusyCount);
+    }
+
     [Fact]
     public void ContainerItem_sendsUseToOpen()
     {
@@ -527,6 +545,7 @@ public sealed class ItemInteractionControllerTests
         h.Objects.AddOrUpdate(new ClientObject
         {
             ObjectId = 0x50000AF2u,
+            Name = "Chainmail Hauberk",
             Type = ItemType.Clothing,
             CurrentlyEquippedLocation = EquipMask.UpperArmWear,
             Priority = 0x00000004u,
@@ -547,6 +566,10 @@ public sealed class ItemInteractionControllerTests
 
         Assert.Empty(h.Wields);
         Assert.Equal(Pack, h.Objects.Get(0x50000A17u)!.ContainerId);
+        Assert.Equal(
+            new[] { "You must remove your Chainmail Hauberk to wear that" },
+            h.SystemMessages);
+        Assert.Empty(h.Toasts);
     }
 
     [Fact]
@@ -563,12 +586,15 @@ public sealed class ItemInteractionControllerTests
         h.AddContained(0x50000A06u, item =>
         {
             item.Type = ItemType.Armor;
+            item.CombatUse = 4; // COMBAT_USE_SHIELD
             item.ValidLocations = EquipMask.Shield;
+            item.Useability = ItemUseability.No;
         });
 
-        Assert.False(h.Controller.ActivateItem(0x50000A06u));
+        bool activated = h.Controller.ActivateItem(0x50000A06u);
 
         Assert.Empty(h.Wields);
+        Assert.False(activated);
         Assert.Equal(Pack, h.Objects.Get(0x50000A06u)!.ContainerId);
     }
 

tests/AcDream.Core.Tests/Items/ItemInteractionPolicyTests.cs

@@ -78,6 +78,30 @@ public sealed class ItemInteractionPolicyTests
             Determine(owned with { Useability = ItemUseability.Contained }));
     }
 
+    [Fact]
+    public void DetermineUseResult_zeroValuedOwnedGem_isRetailItemUse()
+    {
+        var favor = Obj(0x6002) with
+        {
+            Type = ItemType.Gem,
+            ContainerId = Player,
+            OwnedByPlayer = true,
+            Flags = PublicWeenieFlags.RequiresPackSlot,
+            Useability = ItemUseability.Undef,
+        };
+
+        Assert.Equal(ItemPrimaryUseResult.ItemUse, Determine(favor));
+
+        var decision = ItemInteractionPolicy.DecideUse(Use(favor));
+        Assert.Equal(
+            new[]
+            {
+                ItemPolicyActionKind.SendUse,
+                ItemPolicyActionKind.IncrementBusy,
+            },
+            decision.Actions.Select(action => action.Kind));
+    }
+
     [Fact]
     public void DetermineUseResult_nonOwnedGameAndPlayerPaths_areDistinct()
     {
@@ -259,7 +283,7 @@ public sealed class ItemInteractionPolicyTests
         CombatUse: 0,
         ItemsCapacity: 0,
         ContainersCapacity: 0,
-        Useability: 0,
+        Useability: ItemUseability.No,
         TargetType: 0,
         OwnedByPlayer: false,
         IsContainer: false,

tests/AcDream.Core.Tests/Items/ItemUseabilityTests.cs

@@ -28,6 +28,23 @@ public sealed class ItemUseabilityTests
         Assert.False(ItemUseability.IsDirectUseable(ItemUseability.No));
     }
 
+    [Theory]
+    [InlineData(ItemUseability.Undef, true)]
+    [InlineData(ItemUseability.No, false)]
+    [InlineData(ItemUseability.Contained, true)]
+    [InlineData(ItemUseability.NeverWalk, true)]
+    [InlineData(ItemUseability.No | ItemUseability.Contained, false)]
+    public void IsUseable_matchesRetailLowNoBit(uint useability, bool expected)
+    {
+        Assert.Equal(expected, ItemUseability.IsUseable(useability));
+    }
+
+    [Fact]
+    public void Undef_isAZeroValuedDirectUse()
+    {
+        Assert.True(ItemUseability.IsDirectUseable(ItemUseability.Undef));
+    }
+
     [Fact]
     public void LeastLimitedSourceUse_matchesRetailPriorityAndIgnoresObjSelf()
     {