## Summary by CodeRabbit
- **New Features**
- Updated environment variable descriptions for improved clarity on OCR processing options.
- Enhanced the `doOCRViaLLM` method to support different LLM providers and improve image data handling.
- **Bug Fixes**
- Standardized error handling for better reporting across multiple methods.
- **Documentation**
- Revised Docker Compose section in `README.md` to reflect updated environment variable options.