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

自动修复统计:
- 修复了1177个格式问题
- 删除了多余的空行
- 清理了行尾空格
- 移除了重复导入和未使用的导入

backend/neo4j_manager.py

@@ -26,7 +26,6 @@ except ImportError:
     NEO4J_AVAILABLE = False
     logger.warning("Neo4j driver not installed. Neo4j features will be disabled.")
 
-
 @dataclass
 class GraphEntity:
     """图数据库中的实体节点"""
@@ -45,7 +44,6 @@ class GraphEntity:
         if self.properties is None:
             self.properties = {}
 
-
 @dataclass
 class GraphRelation:
     """图数据库中的关系边"""
@@ -61,7 +59,6 @@ class GraphRelation:
         if self.properties is None:
             self.properties = {}
 
-
 @dataclass
 class PathResult:
     """路径查询结果"""
@@ -71,7 +68,6 @@ class PathResult:
     length: int
     total_weight: float = 0.0
 
-
 @dataclass
 class CommunityResult:
     """社区发现结果"""
@@ -81,7 +77,6 @@ class CommunityResult:
     size: int
     density: float = 0.0
 
-
 @dataclass
 class CentralityResult:
     """中心性分析结果"""
@@ -91,7 +86,6 @@ class CentralityResult:
     score: float
     rank: int = 0
 
-
 class Neo4jManager:
     """Neo4j 图数据库管理器"""
 
@@ -998,11 +992,9 @@ class Neo4jManager:
 
             return {"nodes": nodes, "relationships": relationships}
 
-
 # 全局单例
 _neo4j_manager = None
 
-
 def get_neo4j_manager() -> Neo4jManager:
     """获取 Neo4j 管理器单例"""
     global _neo4j_manager
@@ -1010,7 +1002,6 @@ def get_neo4j_manager() -> Neo4jManager:
         _neo4j_manager = Neo4jManager()
     return _neo4j_manager
 
-
 def close_neo4j_manager() -> None:
     """关闭 Neo4j 连接"""
     global _neo4j_manager
@@ -1018,10 +1009,8 @@ def close_neo4j_manager() -> None:
         _neo4j_manager.close()
         _neo4j_manager = None
 
-
 # 便捷函数
 
-
 def sync_project_to_neo4j(
     project_id: str,
     project_name: str,
@@ -1079,7 +1068,6 @@ def sync_project_to_neo4j(
         f"{len(relations)} relations",
     )
 
-
 if __name__ == "__main__":
     # 测试代码
     logging.basicConfig(level=logging.INFO)