Fast, reliable A2UI, with swappable inference formats

A2UI now supports swappable inference formats, including A2UI Express which uses up to 3x fewer tokens and reduces latency by compiling compact Python-style syntax into standard A2UI JSON via Agent SDKs. Developers can use controlled generation with TypeSafe's Jev system-decision models to render known-shape screens in under 300 ms while smaller models stream text. These updates require no changes to frontend renderers or component catalogs and support Python, TypeScript, and Dart.