Function delta_merge_files 

fn delta_merge_files(
    sources: &[&RFile],
    merged_path: &str,
    dependencies: &Dependencies,
    resolutions: &[MergeResolution],
) -> Result<DeltaMergeOutcome>

Delta-merges the decoded DB or Loc sources (same type/table) against the vanilla/parent baseline, applying any already-known resolutions. See rpfm_extensions::merge for the merge rules.