Build the .NET MAUI app skeleton in FmgLib.MauiMarkup fluent C# — Shell with flyouts and tabs, ShellContent routes, flyout templates, per-page Shell attached properties, Application/Window setup, NavigationPage/TabbedPage/FlyoutPage and menus. Use when creating or editing AppShell, App.cs, MauiProgram.cs, navigation structure or window/title-bar setup in a C# markup MAUI app.
