diff --git a/src/MauiSherpa.LinuxGtk/LinuxToolbarManager.cs b/src/MauiSherpa.LinuxGtk/LinuxToolbarManager.cs
index 7865307..6d68654 100644
--- a/src/MauiSherpa.LinuxGtk/LinuxToolbarManager.cs
+++ b/src/MauiSherpa.LinuxGtk/LinuxToolbarManager.cs
@@ -121,12 +121,24 @@ public void AttachToWindow(Gtk.Window window)
         _copilotButton.OnClicked += (s, _) => _copilotContext.ToggleOverlay();
         _headerBar.PackStart(_copilotButton);
 
-        // Settings gear button on the right side
+        // Settings gear button beside copilot
         var settingsButton = Gtk.Button.New();
         settingsButton.SetIconName("emblem-system-symbolic");
         settingsButton.SetTooltipText("Settings");
         settingsButton.OnClicked += (s, _) => OpenSettingsDialog();
-        _headerBar.PackEnd(settingsButton);
+        _headerBar.PackStart(settingsButton);
+
+        // Doctor button beside settings
+        var doctorButton = Gtk.Button.New();
+        var doctorIconName = _themeService.IsDarkMode ? "fa-stethoscope-white-24.png" : "fa-stethoscope-24.png";
+        var doctorIconPath = System.IO.Path.Combine(AppContext.BaseDirectory, "Resources", doctorIconName);
+        if (System.IO.File.Exists(doctorIconPath))
+            doctorButton.SetChild(Gtk.Image.NewFromFile(doctorIconPath));
+        else
+            doctorButton.SetIconName("dialog-information-symbolic");
+        doctorButton.SetTooltipText("Doctor");
+        doctorButton.OnClicked += (s, _) => _toolbarService.RequestNavigation("/doctor");
+        _headerBar.PackStart(doctorButton);
 
         _window.SetTitlebar(_headerBar);
     }
diff --git a/src/MauiSherpa/Components/MainLayout.razor b/src/MauiSherpa/Components/MainLayout.razor
index a0dfafa..62f45db 100644
--- a/src/MauiSherpa/Components/MainLayout.razor
+++ b/src/MauiSherpa/Components/MainLayout.razor
@@ -158,8 +158,7 @@
     protected override void OnInitialized()
     {
         ThemeService.ThemeChanged += OnThemeChanged;
-        if (PlatformInfo.IsWindows)
-            ToolbarService.NavigationRequested += OnNavigationRequested;
+        ToolbarService.NavigationRequested += OnNavigationRequested;
     }
     
     protected override void OnAfterRender(bool firstRender)
@@ -265,8 +264,7 @@
     {
         ThemeService.ThemeChanged -= OnThemeChanged;
         NavManager.LocationChanged -= OnLocationChanged;
-        if (PlatformInfo.IsWindows)
-            ToolbarService.NavigationRequested -= OnNavigationRequested;
+        ToolbarService.NavigationRequested -= OnNavigationRequested;
     }
 
     private void OnLocationChanged(object? sender, Microsoft.AspNetCore.Components.Routing.LocationChangedEventArgs e)
@@ -277,12 +275,25 @@
         ToolbarService.NotifyRouteChanged(route);
     }
 
+    private void OpenCopilot() => CopilotContext.OpenOverlay();
+
     private void OnNavigationRequested(string route)
     {
-        InvokeAsync(() => NavManager.NavigateTo(route));
-    }
+        // Defensively validate/normalize the route coming from native UI
+        if (string.IsNullOrWhiteSpace(route))
+        {
+            return;
+        }
 
-    private void OpenCopilot() => CopilotContext.OpenOverlay();
+        route = route.Trim();
+
+        // Reject absolute URIs/schemes to avoid accidental external navigation
+        if (Uri.TryCreate(route, UriKind.Absolute, out _))
+        {
+            return;
+        }
+        _ = InvokeAsync(() => NavManager.NavigateTo(route));
+    }
 }
 
 <style>