feat: 添加对数据网格指针退出事件的支持，更新相关逻辑以处理悬停提交

Author: heartacker

src/Views/Histories.axaml

@@ -45,6 +45,7 @@
                 LayoutUpdated="OnCommitListLayoutUpdated"
                 SelectionChanged="OnCommitListSelectionChanged"
                 PointerMoved="OnDataGridPointerMoved"
+                PointerExited="OnDataGridPointerExited"
                 ContextRequested="OnCommitListContextRequested"
                 DoubleTapped="OnCommitListDoubleTapped"
                 KeyDown="OnCommitListKeyDown">

src/Views/Histories.axaml.cs

@@ -269,6 +269,12 @@ private void OnDataGridPointerMoved(object sender, PointerEventArgs e)
             }
         }
 
+        private void OnDataGridPointerExited(object sender, PointerEventArgs e)
+        {
+            var hs = (sender as DataGrid)?.DataContext as ViewModels.Histories;
+            hs?.ProcessHoveredCommit(hs.LastSelectedCommit);
+        }
+
         private void OnCommitListContextRequested(object sender, ContextRequestedEventArgs e)
         {
             if (sender is DataGrid { SelectedItems: { } selected } dataGrid &&