style: normalize code formatting across the codebase

- Standardize quote style (single to double quotes)
- Improve code formatting consistency
- Apply formatting to utilities, GUI components, and tools
- Update imports and docstrings for consistency

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

utils/__init__.py

@@ -1,7 +1,8 @@
 """
 工具组件包
 """
+
 from .excel_converter import ExcelConverter
 from .离散备料计划维护数据提取 import DiscreteMaterialPlanExtractor
 
-__all__ = ['ExcelConverter', 'DiscreteMaterialPlanExtractor']
+__all__ = ["ExcelConverter", "DiscreteMaterialPlanExtractor"]