chore: bump version to 0.6.1

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

Version 0.6.0-dev

feat: add MIT license badge and bump version to v0.6.0

- Add MIT license badge to README
- Upgrade version from 0.5.9 to 0.6.0
- Update Dockerfile VERSION argument to match

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

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

Release v0.5.8

Release v0.5.7

Release v0.5.6

Version 0.5.5

Version 0.5.4

Version 0.5.3

Version 0.5.2