Function compile_source_package 

pub fn compile_source_package(
    package: PortableSourcePackage,
    entry: &str,
    entry_kind: EntryKind,
) -> Result<ProgramArtifact, Vec<Diagnostic>>

Parse a resolved source package manifest using the canonical Harn lexer and parser, then compile it through compile_program_package. This keeps the browser and native source-to-artifact path on one frontend; hosts still own import resolution and typechecking before serializing the manifest.