Fix Docker image size badge for GitHub Container Registry

- Replace Docker Hub badge format with GHCR-compatible badge service
- Uses ghcr-badge.egpl.dev which properly supports GitHub Container Registry images
- The previous badge format only works with Docker Hub, not ghcr.io

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: challgren

README.md

@@ -1,6 +1,6 @@
 # Aircraft Patterns - Pattern Detection for ADS-B/TAR1090
 
-[![Docker Image Size](https://img.shields.io/docker/image-size/ghcr.io/challgren/aircraft-patterns/latest)](https://github.com/challgren/aircraft-patterns/pkgs/container/aircraft-patterns)
+[![Docker Image](https://ghcr-badge.egpl.dev/challgren/aircraft-patterns/size?tag=latest&label=image%20size)](https://github.com/challgren/aircraft-patterns/pkgs/container/aircraft-patterns)
 [![License](https://img.shields.io/badge/License-MIT-blue.svg)](LICENSE)
 [![GitHub Issues](https://img.shields.io/github/issues/challgren/aircraft-patterns)](https://github.com/challgren/aircraft-patterns/issues)