Function section_baseline_if_moduled 

pub fn section_baseline_if_moduled(
    module_gen: Option<&ModuleGeneration>,
    baseline_path: &Path,
    new_catalog: &Catalog,
    file_mapping: &FileToObjectMapping,
    historical: &HistoricalAttribution,
) -> Result<()>

Rewrite a freshly created baseline into provenance-cut per-module sections when the project is moduled (a no-op otherwise). The shared tail of the create_baseline(...) capture in migrate new / migrate update: the baseline renders the desired post-V state; the migration’s acquisition sections render from the STARTING catalog instead, so nothing here feeds the migration.