Tray icon: black for light mode, white for dark mode

cmd/desktop/main.go

@@ -33,6 +33,9 @@ var assets embed.FS
 //go:embed icon.png
 var iconPNG []byte
 
+//go:embed icon-dark.png
+var iconDarkPNG []byte
+
 const (
 	keyringService   = "com.hubris.oikos-desktop"
 	keyringUser      = "oikos"
@@ -696,7 +699,8 @@ func main() {
 
 	systemTray := app.SystemTray.New()
 	systemTray.SetTooltip("Oikos")
-	systemTray.SetTemplateIcon(iconPNG)
+	systemTray.SetIcon(iconPNG)
+	systemTray.SetDarkModeIcon(iconDarkPNG)
 
 	trayMenu := application.NewMenu()
 	trayMenu.Add("Open Oikos").OnClick(func(ctx *application.Context) {