Release Help/Release Notes WebView when leaving the page

src/UniGetUI.Avalonia/ViewModels/MainWindowViewModel.cs

@@ -156,16 +156,16 @@
     private void ToggleOperationsPanel() => OperationsPanelExpanded = !OperationsPanelExpanded;
 
     [RelayCommand]
     private void RetryFailedOperations() => AvaloniaOperationRegistry.RetryFailed();
 
     [RelayCommand]
     private void ClearSuccessfulOperations() => AvaloniaOperationRegistry.ClearSuccessful();
 
     [RelayCommand]
     private void ClearFinishedOperations() => AvaloniaOperationRegistry.ClearFinished();
 
     [RelayCommand]
     private void CancelAllOperations() => AvaloniaOperationRegistry.CancelAll();
 
     // ─── Sidebar ─────────────────────────────────────────────────────────────
     public SidebarViewModel Sidebar { get; } = new();
@@ -577,6 +577,13 @@
         NavigateTo(type);
     }
 
+    private void ReleaseWebViewPage(Control? leftPage)
+    {
+        if (leftPage is null) return;
+        if (ReferenceEquals(leftPage, HelpPage)) { HelpPage?.Dispose(); HelpPage = null; }
+        else if (ReferenceEquals(leftPage, ReleaseNotesPage)) { ReleaseNotesPage?.Dispose(); ReleaseNotesPage = null; }
+    }
+
     private Control GetPageForType(PageType type) =>
         type switch
         {
@@ -644,6 +651,10 @@
         _oldPage = _currentPage;
         _currentPage = newPage_t;
 
+        // #5129: Help/ReleaseNotes each host a WebView2 that the control never releases on
+        // detach. Drop the page when leaving so its WebView2 process cluster gets freed.
+        ReleaseWebViewPage(oldPage);
+
         if (toHistory && _oldPage is not PageType.Null)
         {
             NavigationHistory.Add(_oldPage);

src/UniGetUI.Avalonia/Views/Pages/HelpPage.axaml.cs

@@ -4,11 +4,12 @@
 
 namespace UniGetUI.Avalonia.Views.Pages;
 
-public partial class HelpPage : UserControl, IEnterLeaveListener
+public partial class HelpPage : UserControl, IEnterLeaveListener, IDisposable
 {
     private readonly HelpPageViewModel _viewModel;
     private string _pendingNavigation = HelpPageViewModel.HelpBaseUrl;
     private bool _adapterReady;
+    private bool _disposed;
 
     public HelpPage()
     {
@@ -77,4 +78,15 @@ private void HomeButton_Click(object? sender, RoutedEventArgs e) =>
 
     private void ReloadButton_Click(object? sender, RoutedEventArgs e) =>
         WebViewControl.Refresh();
+
+    // Detach the WebView so its WebView2 host/controller is released; the page is
+    // rebuilt fresh on next visit (MainWindowViewModel drops the cached instance).
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+        if (!OperatingSystem.IsLinux())
+            WebViewControl.Stop();
+        WebViewBorder.Child = null;
+    }
 }

src/UniGetUI.Avalonia/Views/Pages/ReleaseNotesPage.axaml.cs

@@ -3,11 +3,12 @@
 
 namespace UniGetUI.Avalonia.Views.Pages;
 
-public partial class ReleaseNotesPage : UserControl, IEnterLeaveListener
+public partial class ReleaseNotesPage : UserControl, IEnterLeaveListener, IDisposable
 {
     private readonly ReleaseNotesPageViewModel _viewModel;
     private bool _loaded;
     private bool _adapterReady;
+    private bool _disposed;
 
     public ReleaseNotesPage()
     {
@@ -52,4 +53,15 @@ public void OnEnter()
     }
 
     public void OnLeave() { }
+
+    // Detach the WebView so its WebView2 host/controller is released; the page is
+    // rebuilt fresh on next visit (MainWindowViewModel drops the cached instance).
+    public void Dispose()
+    {
+        if (_disposed) return;
+        _disposed = true;
+        if (!OperatingSystem.IsLinux())
+            WebViewControl.Stop();
+        WebViewBorder.Child = null;
+    }
 }