* feat: Add stdio transport method.
Update relevant documentation and code to support both SSE and stdio connection methods, initialize the EXCEL_FILES_PATH variable and perform the corresponding path handling.
* Remove PyPI mirror configuration.
- Improve `copy_range_operation` with more robust error handling and style copying
- Enhance `delete_range_operation` with shift direction support
- Update README with Cursor IDE connection instructions
- Remove unnecessary parameters from `create_pivot_table`
- Improve logging and error validation in sheet operations
