Function parse_or_diagnose 

pub fn parse_or_diagnose(
    existing: Option<&str>,
    project_root: &Path,
) -> Result<SchemaRegistry, CompileError>

Parse bynk.schema.lock’s content, diagnosing a corrupt file as bynk.project.schema_registry_corrupt rather than handing the caller a bare String to wrap itself. existing/project_root are exactly bynk_project::schema_registry::parse’s own parameters — None (no lock file yet) always succeeds with a fresh, empty registry.