/// Application-scoped lifecycle registration.
///
/// Handlers registered here run after the last window requests close and before the process
/// exits, while the GLib main loop is still spinning, so they may await.
@MainActor public enum ApplicationLifecycle {
    /// Registers asynchronous teardown to run before the application exits.
    ///
    /// Handlers run sequentially in registration order. A handler registered from an
    /// `App.init()` therefore runs before the app's own `App.shutdown()`.
    ///
    /// - Parameter work: Teardown to perform. Must not itself close windows or quit the app.
    public static func onShutdown(_ work: @escaping @MainActor () async -> Void) {
        PorticoRuntime._register(work)
    }
}