Function build_to_disk 

pub fn build_to_disk(
    options: BuildOptions,
    out_dir: &Path,
) -> Result<BuildStats, WebUIError>

Build a WebUI application and write output files to disk.

Writes protocol.bin, any external CSS files, and static component assets to out_dir. Creates out_dir if it does not exist. Component dependencies publish before roots, unchanged component inputs keep their modification times, and existing files outside the current build are left alone.

Errors

Returns WebUIError on build failure or if output files cannot be written.