- Add output_dir parameter (default: "lunar_json")
- Auto-create directory if not exists
- Update output message to show full file path
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- Add download_ephemeris.sh script for automated JPL ephemeris file downloads
- Support de421, de422, and de440s ephemeris files
- Update README.md with download script usage instructions
- All text in Traditional Chinese
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>