Feat: Add mouse cursor for CupertinoDialogAction (#169051)

This PR updates the mouse pointer behavior for CupertinoDialogAction to
display a pointer cursor when hovering over the action button.
Currently, when hovering over CupertinoDialogAction buttons on desktop
platforms, the default cursor is shown instead of changing to a pointer
cursor, which doesn't provide proper visual feedback to users that the
element is clickable.

## Changes
- Added mouse cursor property to CupertinoDialogAction to display
SystemMouseCursors.click when hovering
- Updated relevant tests to verify the cursor behavior

## Technical Details
The implementation adds the appropriate cursor property to the
CupertinoDialogAction widget, ensuring that when users hover over the
action button on desktop platforms, the cursor changes to a pointer,
indicating that the element is clickable.

## Related Issues
fixes: #169037 (Mouse style doesn't change to pointer when hovering over
CupertinoDialogAction on Desktop)
Part of: #58192 (Add mouse cursor support to the remaining widgets)

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.

---------

Co-authored-by: Tong Mu <dkwingsmt@users.noreply.github.com>
Co-authored-by: chunhtai <47866232+chunhtai@users.noreply.github.com>

packages/flutter/lib/src/cupertino/dialog.dart

@@ -2115,6 +2115,7 @@ class CupertinoDialogAction extends StatefulWidget {
     this.isDefaultAction = false,
     this.isDestructiveAction = false,
     this.textStyle,
+    this.mouseCursor,
     required this.child,
   });
 
@@ -2149,6 +2150,12 @@ class CupertinoDialogAction extends StatefulWidget {
   /// [_kCupertinoDialogActionStyle].
   final TextStyle? textStyle;
 
+  /// The cursor that will be shown when hovering over the button.
+  ///
+  /// If null, defaults to [SystemMouseCursors.click] on web and
+  /// [MouseCursor.defer] on other platforms.
+  final MouseCursor? mouseCursor;
+
   /// The widget below this widget in the tree.
   ///
   /// Typically a [Text] widget.
@@ -2269,7 +2276,8 @@ class _CupertinoDialogActionState extends State<CupertinoDialogAction> implement
             );
 
     return MouseRegion(
-      cursor: widget.onPressed != null && kIsWeb ? SystemMouseCursors.click : MouseCursor.defer,
+      cursor:
+          widget.mouseCursor ?? (enabled && kIsWeb ? SystemMouseCursors.click : MouseCursor.defer),
       child: MetaData(
         metaData: this,
         behavior: HitTestBehavior.opaque,

packages/flutter/test/cupertino/dialog_test.dart

@@ -14,6 +14,7 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart';
+import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
 
 import '../widgets/semantics_tester.dart';
@@ -2117,6 +2118,45 @@ void main() {
     noButton = tester.getCenter(find.text('No'));
     expect(yesButton.dx > noButton.dx, false);
   });
+
+  testWidgets('CupertinoDialogAction.mouseCursor can customize the mouse cursor', (
+    WidgetTester tester,
+  ) async {
+    const SystemMouseCursor customCursor = SystemMouseCursors.grab;
+
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: Directionality(
+          textDirection: TextDirection.ltr,
+          child: CupertinoAlertDialog(
+            actions: <CupertinoDialogAction>[
+              CupertinoDialogAction(
+                mouseCursor: customCursor,
+                child: const Text('Yes'),
+                onPressed: () {},
+              ),
+            ],
+          ),
+        ),
+      ),
+    );
+
+    final TestGesture gesture = await tester.createGesture(
+      kind: PointerDeviceKind.mouse,
+      pointer: 1,
+    );
+    await gesture.addPointer(location: const Offset(10, 10));
+    await tester.pumpAndSettle();
+    expect(
+      RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1),
+      SystemMouseCursors.basic,
+    );
+
+    final Offset actionSheetAction = tester.getCenter(find.text('Yes'));
+    await gesture.moveTo(actionSheetAction);
+    await tester.pumpAndSettle();
+    expect(RendererBinding.instance.mouseTracker.debugDeviceActiveCursor(1), customCursor);
+  });
 }
 
 RenderBox findActionButtonRenderBoxByTitle(WidgetTester tester, String title) {