- Add modular zsh configs: zshrc-dev for dev tools, zshrc-natera for work
- Add .gitignore to exclude private Natera config from version control
- Configure git commit signing and delta diff viewer in gitconfig
- Regenerate p10k.zsh with rainbow theme and improved visual settings
- Add HIST_IGNORE_SPACE option to prevent saving sensitive commands
- Document Natera machine setup with private config template in README