docs: add PyPI version badge to README

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: cursor-usage-cli

README.md

@@ -5,6 +5,7 @@
 </p>
 
 <p align="center">
+  <a href="https://pypi.org/project/cursor-usage/"><img alt="PyPI" src="https://img.shields.io/pypi/v/cursor-usage?color=blue&label=PyPI"></a>
   <img alt="Python" src="https://img.shields.io/badge/python-3.8%2B-blue">
   <img alt="Platforms" src="https://img.shields.io/badge/platform-macOS%20%7C%20Linux%20%7C%20Windows-lightgrey">
   <img alt="Dependencies" src="https://img.shields.io/badge/dependencies-zero-brightgreen">