Generate FmgLib.MauiMarkup fluent extensions for third-party and custom MAUI controls with the Roslyn source generator — [MauiMarkup(typeof(X))], [MauiMarkupAttachedProp], the MauiMarkupSourceGenerator MSBuild switch, base-class generation, the New suffix rule and deliberately skipped members. Use when a control from Syncfusion, UraniumUI, SkiaSharp, ZXing, InputKit, DevExpress, DrawnUI or the user's own library has no fluent methods, or when a fluent method is unexpectedly missing or ambiguous.
