fix: select right-clicked tree node before context menu

Author: fuzzzerd

src/SharpFM/MainWindow.axaml

@@ -177,6 +177,7 @@
                                 <TextBlock Classes="Fluent2Subtitle" Text="Available Clips" />
                                 <TreeView
                                     x:Name="clipsTreeView"
+                                    ContextRequested="ClipsTree_ContextRequested"
                                     DoubleTapped="ClipsTree_DoubleTapped"
                                     ItemsSource="{Binding RootNodes}"
                                     Tapped="ClipsTree_Tapped">

src/SharpFM/MainWindow.axaml.cs

@@ -229,6 +229,17 @@ private void ClipsTree_Tapped(object? sender, TappedEventArgs e)
         vm.OpenClipAsPreview(node.Clip);
     }
 
+    // Right-click bypasses the Tapped handler, so the context menu would
+    // otherwise operate on whatever was previously selected. Promote the
+    // right-clicked node into the active selection before the menu opens.
+    private void ClipsTree_ContextRequested(object? sender, ContextRequestedEventArgs e)
+    {
+        if (DataContext is not MainWindowViewModel vm) return;
+        var node = FindClipNode(e.Source);
+        if (node?.Clip is null) return;
+        vm.OpenClipAsPreview(node.Clip);
+    }
+
     private void ClipsTree_DoubleTapped(object? sender, TappedEventArgs e)
     {
         if (DataContext is not MainWindowViewModel vm) return;