chore: update deps and edgecase coverage

Author: doeixd

README.md

@@ -2,6 +2,7 @@
 
 [![npm version](https://img.shields.io/npm/v/@doeixd/csv-utils.svg)](https://www.npmjs.com/package/@doeixd/csv-utils)
 [![License: MIT](https://img.shields.io/badge/License-MIT-blue.svg)](https://opensource.org/licenses/MIT)
+[![Ask DeepWiki](https://deepwiki.com/badge.svg)](https://deepwiki.com/doeixd/csv-utils)
 
 A TypeScript library for CSV manipulation, featuring robust error handling, strong typing, and a fluent interface. This library provides comprehensive utilities for parsing, transforming, analyzing, and writing CSV data / arrays of objects, with support for operations like header mapping, streaming for large files, schema validation, and async processing.