Renderer
Visitor over a fully resolved tree. A renderer translates each ResolvedNode and each ResolvedChild.TextRun into a platform value of type T.
Parameters
T
the platform output (e.g. Unit for a Compose binding, or a string/AST node for a headless test target).
S
a platform scope threaded through the walk (e.g. a Modifier chain or a composable scope). The engine never inspects it.
The walk is post-order: children are rendered first; the parent receives the already rendered List<T> in renderElement.