Enhance OSF parser with improved data handling and error management

## Summary
- Refactored the OSF parser to introduce a new `parseSheetData` function for better handling of sheet data, including support for semicolons in cell values.
- Updated the `FormulaEvaluator` class to utilize the new data parsing method and ensure type safety with `CellValue`.
- Improved error handling in the `main` function to provide clearer messages when commands or files are missing.
- Enhanced type definitions for OSFValue to support a wider range of data types, including nested structures.
- Expanded test coverage to validate the new parsing capabilities, particularly for semicolons in bullet points and sheet data.

## Testing
- Run `pnpm test` to verify all new and existing tests pass successfully.

Author: alpha912