feat: About dialog with version, commit, build time and settings path

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/ui.cpp

@@ -17,6 +17,7 @@
 #include "acquisition.hpp"
 #include "config.hpp"
 #include "export.hpp"
+#include "help_window.hpp"
 #include "layout_store.hpp"
 #include "measure.hpp"
 #include "model.hpp"
@@ -4083,6 +4084,16 @@ void on_export_clicked(GtkButton*, gpointer user) {
   g_object_unref(dialog);
 }
 
+void on_about_clicked(GtkButton*, gpointer user) {
+  App* app = static_cast<App*>(user);
+  if (app->menu_button != nullptr) {
+    GtkPopover* popover = gtk_menu_button_get_popover(GTK_MENU_BUTTON(app->menu_button));
+    if (popover != nullptr) gtk_popover_popdown(popover);
+  }
+  show_about(GTK_WINDOW(app->window),
+             layout_path(app->model->config().server, app->model->config().port));
+}
+
 // --- right-click menu -------------------------------------------------------
 
 void on_y_auto_clicked(GtkButton* button, gpointer user) {
@@ -5542,6 +5553,13 @@ GtkWidget* build_toolbar(App& app) {
   g_signal_connect(app.signal_toggle, "toggled", G_CALLBACK(on_signals_toggled), &app);
   gtk_box_append(GTK_BOX(menu_box), app.signal_toggle);
 
+  gtk_box_append(GTK_BOX(menu_box), gtk_separator_new(GTK_ORIENTATION_HORIZONTAL));
+
+  GtkWidget* about_item = gtk_button_new_with_label("About udpscope");
+  gtk_widget_set_tooltip_text(about_item, "version, build timestamp and settings paths");
+  g_signal_connect(about_item, "clicked", G_CALLBACK(on_about_clicked), &app);
+  gtk_box_append(GTK_BOX(menu_box), about_item);
+
   GtkWidget* popover = gtk_popover_new();
   gtk_popover_set_child(GTK_POPOVER(popover), menu_box);
   app.menu_button = gtk_menu_button_new();