CmdPal: Honor "Single-click activation" only for pointer clicks and not for keyboard (#41119)

## Summary of the Pull Request

Changes the behavior of keyboard item activation when the item list view
has focus.
Previously, the list view handled item activation according to the
"Single-click activation" setting regardless of the input source (mouse,
pen, touch, or keyboard).

Now, when handling a ListView item click, the input source is detected,
and the "Single-click activation" setting is applied only for
pointer-raised clicks. For keyboard-triggered clicks, items are always
activated immediately.

Since the event `ListView.ItemClick` doesn't provide information about
what caused the item activation, this PR work around that by observing
last user input on the list immediately before `ItemClick` event is
invoked.

## PR Checklist

- [x] Closes: #41101
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

<!-- Provide a more detailed description of the PR, other things fixed,
or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml.cs

@@ -15,6 +15,7 @@ using Microsoft.UI.Xaml.Controls;
 using Microsoft.UI.Xaml.Input;
 using Microsoft.UI.Xaml.Media;
 using Microsoft.UI.Xaml.Navigation;
+using Windows.System;
 
 namespace Microsoft.CmdPal.UI;
 
@@ -24,6 +25,8 @@ public sealed partial class ListPage : Page,
     IRecipient<ActivateSelectedListItemMessage>,
     IRecipient<ActivateSecondaryCommandMessage>
 {
+    private InputSource _lastInputSource;
+
     private ListViewModel? ViewModel
     {
         get => (ListViewModel?)GetValue(ViewModelProperty);
@@ -39,6 +42,8 @@ public sealed partial class ListPage : Page,
         this.InitializeComponent();
         this.NavigationCacheMode = NavigationCacheMode.Disabled;
         this.ItemsList.Loaded += ItemsList_Loaded;
+        this.ItemsList.PreviewKeyDown += ItemsList_PreviewKeyDown;
+        this.ItemsList.PointerPressed += ItemsList_PointerPressed;
     }
 
     protected override void OnNavigatedTo(NavigationEventArgs e)
@@ -98,6 +103,12 @@ public sealed partial class ListPage : Page,
     {
         if (e.ClickedItem is ListItemViewModel item)
         {
+            if (_lastInputSource == InputSource.Keyboard)
+            {
+                ViewModel?.InvokeItemCommand.Execute(item);
+                return;
+            }
+
             var settings = App.Current.Services.GetService<SettingsModel>()!;
             if (settings.SingleClickActivates)
             {
@@ -363,4 +374,21 @@ public sealed partial class ListPage : Page,
     {
         _ = DispatcherQueue.TryEnqueue(() => WeakReferenceMessenger.Default.Send<CloseContextMenuMessage>());
     }
+
+    private void ItemsList_PointerPressed(object sender, PointerRoutedEventArgs e) => _lastInputSource = InputSource.Pointer;
+
+    private void ItemsList_PreviewKeyDown(object sender, KeyRoutedEventArgs e)
+    {
+        if (e.Key is VirtualKey.Enter or VirtualKey.Space)
+        {
+            _lastInputSource = InputSource.Keyboard;
+        }
+    }
+
+    private enum InputSource
+    {
+        None,
+        Keyboard,
+        Pointer,
+    }
 }