Adds a `info: Map<string, RenderInfo>` field to RenderResult that provides post-layout bounding boxes for every named element. Each RenderInfo contains dimensions (x, y, width, height) zero-indexed from the layout root. On the C side, element names and Clay_ElementIds are recorded during layout, then resolved via Clay_GetElementData() after Clay_EndLayout() to extract computed bounding boxes. New WASM exports expose the results to TypeScript.