Added (Experimental Features)
- **`operation`**: Allows combining intermediate fields using Python expressions to dynamically generate BIDS entities.
- **`output_format`**: Lets users specify the output format for BIDS files (`'BrainVision'`, `'EDF'`, `'FIF'`, or `'auto'`).
- **`file_filter`**: Enables regex-based inclusion/exclusion rules to control which files are processed.
⚠️ These features are experimental and may not work correctly in all scenarios.