CmdPal: Add configuration option for Escape key behavior (#43354)

## Summary of the Pull Request

This PR adds a new option to the **General** page in **Settings**:

Escape key behavior — a dropdown with the following choices:

- Clear search first, then go back
  - Current behavior.
  - If the search box contains text, it is cleared; otherwise goes back.
  - On the home page, CmdPal is dismissed.

- Go back
  - Leaves the search text intact.
- If the page is not transient, the search text reappears when
returning.
  - On the home page, CmdPal is dismissed.

- Hide window and go home (Always dismiss)
  - Immediately dismisses CmdPal and navigates to the home page.
  - Ignores the **Go home when activated** setting.
  - Search text is cleared.

- Hide window
  - Just hides the window.
  - Intended to be used with #43355.

This implementation preserves existing behavior, except for **Always
dismiss**, which always forces navigation to the home page.

## Pictures? Pictures!

<img width="1305" height="892" alt="image"
src="https://github.com/user-attachments/assets/562e5604-1da6-4fc6-8358-5053df9c573d"
/>


<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist

- [x] Closes: #38311
- [ ] **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/Controls/SearchBar.xaml.cs

@@ -7,8 +7,10 @@ using CommunityToolkit.WinUI;
 using Microsoft.CmdPal.Core.ViewModels;
 using Microsoft.CmdPal.Core.ViewModels.Commands;
 using Microsoft.CmdPal.Core.ViewModels.Messages;
-using Microsoft.CmdPal.UI.Messages;
+using Microsoft.CmdPal.Ext.ClipboardHistory.Messages;
+using Microsoft.CmdPal.UI.ViewModels;
 using Microsoft.CmdPal.UI.Views;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.UI.Dispatching;
 using Microsoft.UI.Input;
 using Microsoft.UI.Xaml;
@@ -49,6 +51,8 @@ public sealed partial class SearchBar : UserControl,
     // 0.6+ suggestions
     private string? _textToSuggest;
 
+    private SettingsModel Settings => App.Current.Services.GetRequiredService<SettingsModel>();
+
     public PageViewModel? CurrentPageViewModel
     {
         get => (PageViewModel?)GetValue(CurrentPageViewModelProperty);
@@ -131,20 +135,39 @@ public sealed partial class SearchBar : UserControl,
         }
         else if (e.Key == VirtualKey.Escape)
         {
-            if (string.IsNullOrEmpty(FilterBox.Text))
+            switch (Settings.EscapeKeyBehaviorSetting)
             {
-                WeakReferenceMessenger.Default.Send<NavigateBackMessage>(new());
-            }
-            else
-            {
-                // Clear the search box
-                FilterBox.Text = string.Empty;
+                case EscapeKeyBehavior.AlwaysGoBack:
+                    WeakReferenceMessenger.Default.Send<NavigateBackMessage>(new());
+                    break;
 
-                // hack TODO GH #245
-                if (CurrentPageViewModel is not null)
-                {
-                    CurrentPageViewModel.SearchTextBox = FilterBox.Text;
-                }
+                case EscapeKeyBehavior.AlwaysDismiss:
+                    WeakReferenceMessenger.Default.Send<DismissMessage>(new(ForceGoHome: true));
+                    break;
+
+                case EscapeKeyBehavior.AlwaysHide:
+                    WeakReferenceMessenger.Default.Send<HideWindowMessage>(new());
+                    break;
+
+                case EscapeKeyBehavior.ClearSearchFirstThenGoBack:
+                default:
+                    if (string.IsNullOrEmpty(FilterBox.Text))
+                    {
+                        WeakReferenceMessenger.Default.Send<NavigateBackMessage>(new());
+                    }
+                    else
+                    {
+                        // Clear the search box
+                        FilterBox.Text = string.Empty;
+
+                        // hack TODO GH #245
+                        if (CurrentPageViewModel is not null)
+                        {
+                            CurrentPageViewModel.SearchTextBox = FilterBox.Text;
+                        }
+                    }
+
+                    break;
             }
 
             e.Handled = true;