fix(ui): retail target-cursor shape (pending over UI, world-object driven) + visible UseDone refusals

Visual gate round 2 (user, retail oracle): the target cursor over UI must
be the 0x27 four-arrows PENDING cursor — retail's UpdateCursorState
(0x00564630) keys valid/invalid solely off the SmartBox found object,
i.e. the WORLD entity under the cursor. And "can't heal myself" turned
out to be TWO stacked causes, both fixed:

- Cursor: UI hover no longer forces TargetInvalid (that arm was a
  non-retail invention) and the doll/status-bar hover providers are
  gone (UiElement.UseTargetGuidProvider deleted). Valid/invalid now
  come from (a) a hovered occupied item slot's own item, or (b) the
  world entity under the cursor via a new worldTargetProvider — the
  B.4b screen-rect picker extracted into GameWindow.PickWorldGuidAtCursor
  and shared by click + hover.
- Self-heal: the world picker always skipped the local player
  (skipServerGuid), so clicking your own toon in target mode could
  never acquire self. Target-use picks now include self (retail lets
  you kit-heal yourself by clicking your character); plain selection
  keeps the exclusion. The doll click still self-targets.
- Silent refusals: the [use-target] log proved the UseWithTarget action
  WAS sent (kit 0x00220008 / TargetType 0x10, target self) — ACE
  refused with WeenieError.YouArentTrainedInHealing (0x04FC) and we
  never parsed UseDone (0x01C7). Now dispatched + surfaced as a chat
  line via WeenieErrorText (interim subset map, register AP-74, #166
  ports the retail String-table lookup).

Full suite green (3,295).

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

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

@@ -75,16 +75,19 @@ public sealed class CursorFeedbackControllerTests
             c.Resolve(new CursorFeedbackSnapshot(HoverUi: true, HoverTargetGuid: Player)).Kind);
         Assert.Equal(CursorFeedbackKind.TargetInvalid,
             c.Resolve(new CursorFeedbackSnapshot(HoverUi: true, HoverTargetGuid: 0x5000BADu)).Kind);
-        Assert.Equal(CursorFeedbackKind.TargetInvalid,
+        // Retail UpdateCursorState: no found object → PENDING, including over
+        // UI chrome (the HoverUi→Invalid arm was a non-retail invention).
+        Assert.Equal(CursorFeedbackKind.TargetPending,
             c.Resolve(new CursorFeedbackSnapshot(HoverUi: true)).Kind);
         Assert.Equal(CursorFeedbackKind.TargetPending,
             c.Resolve(new CursorFeedbackSnapshot()).Kind);
     }
 
     [Fact]
-    public void UpdateFromRoot_usesUseTargetGuidProviderBeforeSlotItem()
+    public void UpdateFromRoot_slotItemDrivesTargetCursor_withStateArt()
     {
         var objects = SeedTargetObjects();
+        objects.Get(Source)!.TargetType = (uint)ItemType.Misc;   // a tool that targets items
         var interaction = new ItemInteractionController(
             objects,
             playerGuid: () => Player,
@@ -100,7 +103,6 @@ public sealed class CursorFeedbackControllerTests
             Top = 10,
             Width = 32,
             Height = 32,
-            UseTargetGuidProvider = () => Player,
         };
         var acceptCursor = new UiCursorMedia(0x06009999u, 11, 12);
         slot.SetStateCursors(new Dictionary<string, UiCursorMedia>
@@ -119,6 +121,34 @@ public sealed class CursorFeedbackControllerTests
         Assert.Equal(acceptCursor, feedback.Cursor);
     }
 
+    [Fact]
+    public void UpdateFromRoot_worldProviderDrivesTargetCursor_whenUiNotHovered()
+    {
+        var objects = SeedTargetObjects();
+        var interaction = new ItemInteractionController(
+            objects,
+            playerGuid: () => Player,
+            sendUse: null,
+            sendUseWithTarget: null,
+            sendWield: null,
+            sendDrop: null,
+            nowMs: () => 1_000);
+        var root = new UiRoot { Width = 800, Height = 600 };   // nothing under the mouse
+        root.OnMouseMove(400, 300);
+        var c = new CursorFeedbackController(interaction, worldTargetProvider: () => Player);
+
+        Assert.True(interaction.ActivateItem(Source));
+
+        // World hover (retail SmartBox found object) drives valid/invalid…
+        Assert.Equal(CursorFeedbackKind.TargetValid, c.Update(root).Kind);
+
+        // …but UI occludes the world: hovering a plain panel → PENDING even
+        // though the world provider would return a valid target.
+        var panel = new UiPanel { Left = 390, Top = 290, Width = 40, Height = 40 };
+        root.AddChild(panel);
+        Assert.Equal(CursorFeedbackKind.TargetPending, c.Update(root).Kind);
+    }
+
     private static ClientObjectTable SeedTargetObjects()
     {
         var objects = new ClientObjectTable();