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/security_manager.py

@@ -25,7 +25,6 @@ except ImportError:
     CRYPTO_AVAILABLE = False
     print("Warning: cryptography not available, encryption features disabled")
 
-
 class AuditActionType(Enum):
     """审计动作类型"""
 
@@ -48,7 +47,6 @@ class AuditActionType(Enum):
     WEBHOOK_SEND = "webhook_send"
     BOT_MESSAGE = "bot_message"
 
-
 class DataSensitivityLevel(Enum):
     """数据敏感度级别"""
 
@@ -57,7 +55,6 @@ class DataSensitivityLevel(Enum):
     CONFIDENTIAL = "confidential"  # 机密
     SECRET = "secret"  # 绝密
 
-
 class MaskingRuleType(Enum):
     """脱敏规则类型"""
 
@@ -69,7 +66,6 @@ class MaskingRuleType(Enum):
     ADDRESS = "address"  # 地址
     CUSTOM = "custom"  # 自定义
 
-
 @dataclass
 class AuditLog:
     """审计日志条目"""
@@ -91,7 +87,6 @@ class AuditLog:
     def to_dict(self) -> dict[str, Any]:
         return asdict(self)
 
-
 @dataclass
 class EncryptionConfig:
     """加密配置"""
@@ -109,7 +104,6 @@ class EncryptionConfig:
     def to_dict(self) -> dict[str, Any]:
         return asdict(self)
 
-
 @dataclass
 class MaskingRule:
     """脱敏规则"""
@@ -129,7 +123,6 @@ class MaskingRule:
     def to_dict(self) -> dict[str, Any]:
         return asdict(self)
 
-
 @dataclass
 class DataAccessPolicy:
     """数据访问策略"""
@@ -151,7 +144,6 @@ class DataAccessPolicy:
     def to_dict(self) -> dict[str, Any]:
         return asdict(self)
 
-
 @dataclass
 class AccessRequest:
     """访问请求（用于需要审批的访问）"""
@@ -169,7 +161,6 @@ class AccessRequest:
     def to_dict(self) -> dict[str, Any]:
         return asdict(self)
 
-
 class SecurityManager:
     """安全管理器"""
 
@@ -1194,11 +1185,9 @@ class SecurityManager:
             created_at=row[8],
         )
 
-
 # 全局安全管理器实例
 _security_manager = None
 
-
 def get_security_manager(db_path: str = "insightflow.db") -> SecurityManager:
     """获取安全管理器实例"""
     global _security_manager