Function build_native_bundle 

pub fn build_native_bundle(
    source: &str,
    bundle_dir: &Path,
) -> Result<Vec<(String, PathBuf)>, ParseError>

Pre-build every native-annotated function in source into the AOT bundle under bundle_dir (HOTSWAP §Axis-3 / P16 — the “tools to bundle them”). Returns the (function_name, cdylib_path) manifest. Functions outside the sound scalar subset are silently skipped — they keep running on VM+JIT, no gap at the seam. Err only on a genuine parse/type error.