main.cpp)main.cpp bootstraps GTK, initialises the data model, and launches the main
window. This module is intentionally thin—most logic lives in dedicated classes.
Gtk::Application::create().DatabaseManager, call ensure_schema().BookList with the database manager and load the existing books.BibliothecaWindow (passing the BookList reference) and add it to
the application.app->run(window).The entry point is also the place to install global actions/startup handlers if you expand the app (e.g., register keyboard shortcuts or file-open hooks).