bite: SwiftUI components library demos

I shipped d60e0e1 in SwiftyBites with a new SwiftUIComponentsLibrary area for pickers, menus, search scopes and tokens, and width-showcase layouts.

The useful part is not just the snippets themselves, but that AI agents researched the best practices, produced the example code, organized the project, and left me with a runnable playground where I can compare equal-width stacks, GeometryReader, PreferenceKey, and some surprisingly similar results against my actual needs.