Centralize legacy app shell services

src/legacy_app_shell_services.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "app_core/about_menu.h"
+#include "app_core/document_export.h"
+#include "app_core/file_menu.h"
+#include "app_core/main_toolbar.h"
+#include "app_core/tools_menu.h"
+
+class App;
+
+namespace pp::panopainter {
+
+[[nodiscard]] bool apply_legacy_document_export_menu_plan(
+    App& app,
+    pp::app::DocumentExportMenuKind kind);
+void apply_legacy_file_menu_command(
+    App& app,
+    pp::app::FileMenuCommand command);
+void execute_legacy_main_toolbar_plan(
+    App& app,
+    const pp::app::MainToolbarPlan& plan);
+void execute_legacy_about_menu_plan(
+    App& app,
+    const pp::app::AboutMenuPlan& plan);
+void execute_legacy_tools_menu_plan(
+    App& app,
+    const pp::app::ToolsMenuPlan& plan);
+
+} // namespace pp::panopainter