refactor: add type hints and FileParser.is_supported() helper

- Add return type annotation (list[str]) to Config.validate()
- Add type annotations (msg: str, -> None) to logger convenience functions
- Add FileParser.is_supported() classmethod for checking file format support

backend/app/config.py

@@ -64,9 +64,9 @@ class Config:
     REPORT_AGENT_TEMPERATURE = float(os.environ.get('REPORT_AGENT_TEMPERATURE', '0.5'))
     
     @classmethod
-    def validate(cls):
+    def validate(cls) -> list[str]:
         """验证必要配置"""
-        errors = []
+        errors: list[str] = []
         if not cls.LLM_API_KEY:
             errors.append("LLM_API_KEY 未配置")
         if not cls.ZEP_API_KEY:

backend/app/utils/file_parser.py

@@ -63,6 +63,20 @@ class FileParser:
     
     SUPPORTED_EXTENSIONS = {'.pdf', '.md', '.markdown', '.txt'}
     
+    @classmethod
+    def is_supported(cls, file_path: str) -> bool:
+        """
+        检查文件是否为支持的格式
+        
+        Args:
+            file_path: 文件路径
+            
+        Returns:
+            如果文件格式受支持则返回 True
+        """
+        suffix = Path(file_path).suffix.lower()
+        return suffix in cls.SUPPORTED_EXTENSIONS
+    
     @classmethod
     def extract_text(cls, file_path: str) -> str:
         """

backend/app/utils/logger.py

@@ -109,18 +109,18 @@ logger = setup_logger()
 
 
 # 便捷方法
-def debug(msg, *args, **kwargs):
+def debug(msg: str, *args, **kwargs) -> None:
     logger.debug(msg, *args, **kwargs)
 
-def info(msg, *args, **kwargs):
+def info(msg: str, *args, **kwargs) -> None:
     logger.info(msg, *args, **kwargs)
 
-def warning(msg, *args, **kwargs):
+def warning(msg: str, *args, **kwargs) -> None:
     logger.warning(msg, *args, **kwargs)
 
-def error(msg, *args, **kwargs):
+def error(msg: str, *args, **kwargs) -> None:
     logger.error(msg, *args, **kwargs)
 
-def critical(msg, *args, **kwargs):
+def critical(msg: str, *args, **kwargs) -> None:
     logger.critical(msg, *args, **kwargs)