Function read_unstable_config 

pub fn read_unstable_config(
    project_root: &Path,
    overlay: &HashMap<PathBuf, String>,
) -> UnstableConfig

The project’s [unstable] table as both the build and the editor see it (#1963 Decision E): the overlay’s bynk.toml when it holds one (the LSP puts the open buffer there), otherwise the one on disk (a CLI build’s overlay holds only .bynk sources). A missing or malformed manifest reads as empty; its shape errors are check_manifest’s to report.