Function apply_manifest_diff 

pub fn apply_manifest_diff(
    database_path: &Path,
    base_manifest: &Manifest,
    new_manifest: &Manifest,
    callgraph_blob_database: &Path,
) -> Result<MaterializeStats>

Apply to a private copy of the base generation’s database, never a published file. The caller owns copying, durability and pointer publication. All graph changes and the fingerprint commit atomically; errors roll back to the supplied base. An old binding-cache schema takes the cold path; a mismatched manifest is refused.