fix(ui): retail-faithful use-target compat gate + paperdoll doll self-target

Visual gate on the item-interaction slice found two target-use bugs:
the valid-target bullseye showed over inventory ITEMS (a coat is not a
valid healing-kit target) while the paperdoll doll showed blocked (it
should mean SELF).

- TargetCompatible is now a faithful port of
  ItemHolder::IsTargetCompatibleWithTargetingObject (0x00588070):
  a location constraint applies only when the least-limited target-use
  bit (ItemUses::GetLeastLimitedTargetUse 0x004fcd50, new
  ItemUseability.LeastLimitedTargetUse) is Contained/Wielded; the
  player as target requires the Self bit (IsUseable_SelfTarget
  0x004fcd30); and EVERY target passes retail's kind gate
  source._targetType & target->InqType(). The previous hand-rolled
  arms (Remote => accept anything, invented Viewed/Contained accepts,
  self path skipping the kind gate) were the yellow-over-items bug.
  Retail's tradeState refusal is skipped (no trade state yet).
- The paperdoll doll viewport now carries UseTargetGuidProvider =
  player and Clicked -> AcquireSelfTarget (UiViewport gains an opt-in
  Clicked handler), so hovering the doll resolves the self cursor and
  clicking it applies the armed kit to yourself.
- AcquireTarget logs one [use-target] line (wire useability, TargetType
  mask, target kind, decision) so live refusals are diagnosable from
  the launch log.
- Test fixtures updated from the guessed kit useability 0x000A0008 to
  the real USEABLE_SOURCE_CONTAINED_TARGET_REMOTE_OR_SELF (0x00220008,
  ACE Usable.SourceContainedTargetRemoteOrSelf) + TargetType masks;
  new coverage pins the kind gate, the Self-bit requirement, the
  missing-mask-matches-nothing shape, and the Contained location rule.

Full suite green (3,294).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/UI/ItemInteractionController.cs

@@ -150,7 +150,13 @@ public sealed class ItemInteractionController
         if (source?.Useability is not { } useability)
             return false;
 
-        if (!TargetCompatible(source, targetGuid, useability))
+        bool compatible = TargetCompatible(source, targetGuid, useability);
+        var target = _objects.Get(targetGuid);
+        Console.WriteLine(
+            $"[use-target] src=0x{sourceGuid:X8} use=0x{useability:X8} ttypeMask=0x{source.TargetType ?? 0u:X8}"
+            + $" tgt=0x{targetGuid:X8} tgtKind={(target is null ? "none" : $"0x{(uint)target.Type:X8}")}"
+            + $" -> {(compatible ? "SEND UseWithTarget" : "refused")}");
+        if (!compatible)
             return false;
 
         _sendUseWithTarget?.Invoke(sourceGuid, targetGuid);
@@ -333,30 +339,48 @@ public sealed class ItemInteractionController
         return false;
     }
 
+    /// <summary>
+    /// Faithful port of <c>ItemHolder::IsTargetCompatibleWithTargetingObject</c>
+    /// (0x00588070) for a player-owned source (ActivateItem's SourceCompatible
+    /// already applied retail's GetLeastLimitedSourceUse arm when target mode was
+    /// armed). Retail shape: (1) a LOCATION constraint applies only when the
+    /// least-limited target-use bit (ItemUses::GetLeastLimitedTargetUse
+    /// 0x004fcd50) is Contained — target must be in our inventory, sole
+    /// exception self when the Self bit is present — or Wielded (refuse
+    /// non-owned); (2) the player as target additionally requires the Self bit
+    /// (ItemUses::IsUseable_SelfTarget 0x004fcd30); (3) EVERY target then passes
+    /// the KIND gate: <c>source._targetType &amp; target-&gt;InqType()</c>. A
+    /// missing/zero TargetType mask therefore matches nothing, exactly like
+    /// retail. Retail's tradeState!=1 refusal is skipped — acdream has no trade
+    /// state yet. The previous per-bit arms (Remote ⇒ accept-anything, invented
+    /// Viewed/Contained accepts, self path skipping the kind gate) were the
+    /// 2026-07-03 "yellow bullseye over a coat" bug.
+    /// </summary>
     private bool TargetCompatible(ClientObject source, uint targetGuid, uint useability)
     {
         uint flags = ItemUseability.TargetFlags(useability);
         uint player = _playerGuid();
 
-        if (targetGuid == source.ObjectId && (flags & ItemUseability.ObjSelf) != 0)
-            return true;
-
-        if (targetGuid == player)
-            return (flags & ItemUseability.Self) != 0;
-
         var target = _objects.Get(targetGuid);
         if (target is null)
-            return (flags & ItemUseability.Remote) != 0;
+            return false;   // retail: GetWeenieObject(target) null → incompatible
 
-        if (source.TargetType is { } targetType && targetType != 0
-            && ((uint)target.Type & targetType) == 0)
+        if (!(IsCarriedByPlayer(target) || IsEquippedByPlayer(target)))
+        {
+            uint least = ItemUseability.LeastLimitedTargetUse(useability);
+            if ((least & ItemUseability.Contained) != 0)
+            {
+                if (!(targetGuid == player && (flags & ItemUseability.Self) != 0))
+                    return false;
+            }
+            else if ((least & ItemUseability.Wielded) != 0)
+                return false;
+        }
+
+        if (targetGuid == player && (flags & ItemUseability.Self) == 0)
             return false;
 
-        if ((flags & ItemUseability.Wielded) != 0 && IsWieldedByPlayer(target)) return true;
-        if ((flags & ItemUseability.Contained) != 0 && IsCarriedByPlayer(target)) return true;
-        if ((flags & ItemUseability.Viewed) != 0 && IsCarriedByPlayer(target)) return true;
-        if ((flags & ItemUseability.Remote) != 0) return true;
-        return false;
+        return ((source.TargetType ?? 0u) & (uint)target.Type) != 0;
     }
 
     private bool IsWieldedByPlayer(ClientObject item)

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

@@ -125,6 +125,15 @@ public sealed class PaperdollController : IItemListDragHandler
             if (layout.FindElement(id) is UiItemList armor) _armorSlots.Add(armor);
 
         _dollViewport = layout.FindElement(0x100001D5u);   // doll viewport (may be null until Slice 3)
+        if (_dollViewport is not null)
+        {
+            // The doll IS the player: hovering it during target-use resolves the
+            // valid/invalid cursor for SELF (retail: the SmartBox target is your
+            // own creature), and clicking it self-targets like the equip cells.
+            _dollViewport.UseTargetGuidProvider = _playerGuid;
+            if (_dollViewport is UiViewport doll)
+                doll.Clicked = () => { _itemInteraction?.AcquireSelfTarget(); };
+        }
 
         var slotsBtnEl = layout.FindElement(0x100005BEu);
         if (slotsBtnEl is UiButton slotsBtn)

src/AcDream.App/UI/UiViewport.cs

@@ -9,6 +9,24 @@ public sealed class UiViewport : UiElement
 {
     public override bool ConsumesDatChildren => true;
 
+    /// <summary>Optional click action (e.g. the paperdoll doll = "target self"
+    /// during item target-use). Non-null makes the viewport handle the press
+    /// itself instead of it being captured as a window move.</summary>
+    public System.Action? Clicked { get; set; }
+
+    public override bool HandlesClick => Clicked is not null;
+
+    public override bool OnEvent(in UiEvent e)
+    {
+        if (Clicked is null) return base.OnEvent(e);
+        switch (e.Type)
+        {
+            case UiEventType.MouseDown: return true;   // consume the press; act on Click
+            case UiEventType.Click: Clicked.Invoke(); return true;
+        }
+        return base.OnEvent(e);
+    }
+
     /// <summary>Renderer that produces the off-screen texture. Set by GameWindow wiring (later task).</summary>
     public IUiViewportRenderer? Renderer { get; set; }