Use CachedViewsUnderMouse in HandleAutoGrabPress; skip disabled SubViews

Replace the redundant GetViewsUnderLocation call with a read from the
already-populated CachedViewsUnderMouse. Walk the cache backwards to
find the deepest *enabled* view, so disabled SubViews don't block the
SuperView from grabbing the mouse.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Terminal.Gui/ViewBase/Mouse/View.Mouse.cs

@@ -572,21 +572,26 @@ public partial class View // Mouse APIs
             return false;
         }
 
-        // Don't grab if a SubView at the mouse position can handle the event
-        // This ensures that SubViews receive their own mouse events even when the SuperView has MouseHighlightStates set
-        if (mouse.Position is { } pos && Viewport.Contains (pos))
+        // Don't grab if an enabled SubView at the mouse position can handle the event.
+        // CachedViewsUnderMouse is already updated by RaiseMouseEnterLeaveEvents before NewMouseEvent runs.
+        // Disabled views are included in the cache, so we must find the deepest enabled view.
+        if (App?.Mouse.CachedViewsUnderMouse is { Count: > 0 } cached)
         {
-            // Convert viewport-relative position to screen coordinates
-            Point screenPos = ViewportToScreen (pos);
+            View? deepestEnabledView = null;
 
-            // Get all views under this screen position - the deepest view is at the end of the list
-            List<View?> viewsUnderMouse = GetViewsUnderLocation (screenPos, ViewportSettingsFlags.TransparentMouse);
-            View? deepestView = viewsUnderMouse.LastOrDefault ();
-
-            // If the deepest view is a SubView of this view (not this view itself), don't grab
-            if (deepestView is { } && deepestView != this)
+            for (int i = cached.Count - 1; i >= 0; i--)
             {
-                // A SubView is under the cursor - let it handle its own events
+                if (cached [i] is { Enabled: true } candidate)
+                {
+                    deepestEnabledView = candidate;
+
+                    break;
+                }
+            }
+
+            if (deepestEnabledView is { } && deepestEnabledView != this)
+            {
+                // An enabled SubView is under the cursor - let it handle its own events
                 return false;
             }
         }

Tests/UnitTestsParallelizable/ViewBase/Mouse/MouseHighlightStatesSubViewTests.cs

@@ -225,6 +225,68 @@ public class MouseHighlightStatesSubViewTests
         runnable.Dispose ();
     }
 
+    /// <summary>
+    ///     Tests that when a SubView is disabled, clicking on it routes the event to the SuperView.
+    ///     A disabled SubView should not prevent the SuperView from grabbing the mouse.
+    /// </summary>
+
+    // Claude - Opus 4.6
+    [Theory]
+    [InlineData (MouseState.In)]
+    [InlineData (MouseState.Pressed)]
+    [InlineData (MouseState.In | MouseState.Pressed)]
+    public void MouseHighlightStates_DisabledSubView_DoesNotPreventSuperViewGrab (MouseState highlightState)
+    {
+        // Arrange
+        VirtualTimeProvider time = new ();
+        using IApplication app = Application.Create (time);
+        app.Init (DriverRegistry.Names.ANSI);
+
+        var superViewActivateCount = 0;
+        var subViewActivateCount = 0;
+
+        Runnable runnable = new ();
+
+        View superView = new ()
+        {
+            Id = "superView",
+            X = 0,
+            Y = 0,
+            Width = 10,
+            Height = 10,
+            MouseHighlightStates = highlightState
+        };
+
+        superView.Activating += (_, _) => { superViewActivateCount++; };
+
+        View subView = new ()
+        {
+            Id = "disabledSubView",
+            X = 2,
+            Y = 2,
+            Width = 5,
+            Height = 5,
+            CanFocus = true,
+            Enabled = false
+        };
+
+        subView.Activating += (_, _) => { subViewActivateCount++; };
+
+        superView.Add (subView);
+        runnable.Add (superView);
+        app.Begin (runnable);
+
+        // Act: Click on the disabled SubView at screen position (3, 3)
+        app.InjectMouse (new Mouse { ScreenPosition = new Point (3, 3), Flags = MouseFlags.LeftButtonPressed });
+        app.InjectMouse (new Mouse { ScreenPosition = new Point (3, 3), Flags = MouseFlags.LeftButtonReleased });
+
+        // Assert: SuperView should receive the event since SubView is disabled
+        Assert.Equal (1, superViewActivateCount);
+        Assert.Equal (0, subViewActivateCount);
+
+        runnable.Dispose ();
+    }
+
     /// <summary>
     ///     Tests that nested views (SuperView with MouseHighlightStates, SubView with MouseHighlightStates)
     ///     route events to the deepest view under the mouse.