Function search_with_options 

pub fn search_with_options(
    query: &str,
    target_path: &str,
    opts: &SearchOptions,
) -> Vec<Snippet>

Run the full 3-stage search pipeline and return ranked results.

The returned Vec<Snippet> is sorted by descending score, truncated to opts.top_k entries. Each snippet carries its file path, line range, content bytes, and final KMI-reranked score.