Function summarize 

pub fn summarize(
    source: &str,
    language: &str,
    file_path: &str,
    config: &SummaryConfig,
    dep_mapper: Option<&DependencyMapper>,
) -> Result<StructuralSummaryResult>

Extract a structural summary from source code.

This is the main entry point. Given source code and its language, produces a compact summary containing imports, signatures, call relationships, and dependency info.