surface UAC consent prompt in the foreground

src/UniGetUI.Avalonia/Views/MainWindow.axaml.cs

@@ -14,6 +14,7 @@
 using UniGetUI.Avalonia.Infrastructure;
 using UniGetUI.Avalonia.ViewModels;
 using UniGetUI.Avalonia.Views.Pages;
+using UniGetUI.Core.Data;
 using UniGetUI.Core.Logging;
 using UniGetUI.Core.SettingsEngine;
 using UniGetUI.Core.Tools;
@@ -140,6 +141,12 @@ public MainWindow()
 
         _trayService = new TrayService(this);
         _trayService.UpdateStatus();
+
+        // Let the elevation code activate us right before a UAC prompt, so we own the foreground
+        // and can delegate it to the consent UI (#5146). Only activate when we're already on screen;
+        // don't yank a tray-hidden window forward during silent/background elevation.
+        CoreData.BringMainWindowToForegroundAsync = () =>
+            Dispatcher.UIThread.InvokeAsync(() => { if (IsVisible) ShowFromTray(); }).GetTask();
     }
 
     protected override void OnOpened(EventArgs e)

src/UniGetUI.Core.Data/CoreData.cs

@@ -427,6 +427,14 @@ public static string UniGetUIExecutableFile
         /// </summary>
         public static string ElevatorArgs = "";
 
+        /// <summary>
+        /// Set by the UI layer to bring the main window to the foreground and wait until it is.
+        /// Called right before a UAC prompt is triggered so the app owns the foreground and can
+        /// delegate it to the consent UI (fixes prompts hiding behind the window with secure desktop off).
+        /// Null in headless mode, where no window exists to activate.
+        /// </summary>
+        public static Func<Task>? BringMainWindowToForegroundAsync;
+
         /// <summary>
         /// This method will return the most appropriate data directory.
         /// If the new directory exists, it will be used.

src/UniGetUI.Core.Tools/Tools.cs

@@ -603,6 +603,31 @@ public static string EnsureSafeQueryString(string query)
             return new Uri(url);
         }
 
+        // Grants every process the right to set the foreground window, bypassing the
+        // foreground lock so a UAC consent prompt can surface in front. ASFW_ANY = -1.
+        private const int ASFW_ANY = -1;
+
+        [DllImport("user32.dll", SetLastError = true)]
+        [return: MarshalAs(UnmanagedType.Bool)]
+        private static extern bool AllowSetForegroundWindow(int dwProcessId);
+
+        /// <summary>
+        /// Windows: bring UniGetUI to the foreground and grant foreground rights so an imminent
+        /// UAC consent prompt surfaces in front instead of only flashing the taskbar (#5146).
+        /// No-op elsewhere, and when the app owns no visible foreground window to delegate.
+        /// Must be called immediately before launching the elevator.
+        /// </summary>
+        public static async Task PrepareForegroundForElevationAsync()
+        {
+            if (!OperatingSystem.IsWindows())
+                return;
+
+            var bringToFront = CoreData.BringMainWindowToForegroundAsync;
+            if (bringToFront is not null)
+                await bringToFront();
+            AllowSetForegroundWindow(ASFW_ANY);
+        }
+
         /// <summary>
         /// Enables GSudo cache for the current process
         /// </summary>
@@ -656,6 +681,11 @@ public static async Task CacheUACForCurrentProcess()
                         StandardOutputEncoding = Encoding.UTF8,
                     },
                 };
+
+                // When admin-rights caching is enabled, the UAC consent prompt is raised here.
+                // Surface it in front instead of letting it flash unnoticed in the taskbar (#5146).
+                await PrepareForegroundForElevationAsync();
+
                 p.Start();
                 await p.WaitForExitAsync();
                 _isCaching = false;

src/UniGetUI.PackageEngine.Operations/AbstractProcessOperation.cs

@@ -1,5 +1,6 @@
 using System.Diagnostics;
 using System.Text;
+using UniGetUI.Core.Data;
 using UniGetUI.Core.Logging;
 using UniGetUI.Core.SettingsEngine;
 using UniGetUI.Core.Tools;
@@ -106,6 +107,13 @@ protected override async Task<OperationVeredict> PerformOperation()
         }
 
         CancellationToken.ThrowIfCancellationRequested();
+
+        // When admin-rights caching is disabled (or a cache miss), the elevator is launched
+        // directly here and the UAC prompt is raised at this Start() — bring it to the
+        // foreground too, not just on the cached path (#5146).
+        if (process.StartInfo.FileName == CoreData.ElevatorPath)
+            await CoreTools.PrepareForegroundForElevationAsync();
+
         process.Start();
         if (CancellationToken.IsCancellationRequested)
         {