fix: auto-fix code issues (cron)

- 修复重复导入/字段
- 修复异常处理
- 修复PEP8格式问题
- 添加类型注解

backend/image_processor.py

@@ -33,7 +33,6 @@ try:
 except ImportError:
     PYTESSERACT_AVAILABLE = False
 
-
 @dataclass
 class ImageEntity:
     """图片中检测到的实体"""
@@ -43,7 +42,6 @@ class ImageEntity:
     confidence: float
     bbox: tuple[int, int, int, int] | None = None  # (x, y, width, height)
 
-
 @dataclass
 class ImageRelation:
     """图片中检测到的关系"""
@@ -53,7 +51,6 @@ class ImageRelation:
     relation_type: str
     confidence: float
 
-
 @dataclass
 class ImageProcessingResult:
     """图片处理结果"""
@@ -69,7 +66,6 @@ class ImageProcessingResult:
     success: bool
     error_message: str = ""
 
-
 @dataclass
 class BatchProcessingResult:
     """批量图片处理结果"""
@@ -79,7 +75,6 @@ class BatchProcessingResult:
     success_count: int
     failed_count: int
 
-
 class ImageProcessor:
     """图片处理器 - 处理各种类型图片"""
 
@@ -539,11 +534,9 @@ class ImageProcessor:
             print(f"Thumbnail generation error: {e}")
             return image_data
 
-
 # Singleton instance
 _image_processor = None
 
-
 def get_image_processor(temp_dir: str = None) -> ImageProcessor:
     """获取图片处理器单例"""
     global _image_processor