fix: 修复代码质量问题 - 更正异常处理和导入语句

Co-authored-by: Windpicker-owo <221029311+Windpicker-owo@users.noreply.github.com>

src/memory_graph/manager_singleton.py

@@ -7,7 +7,6 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import Optional
 
 from src.common.logger import get_logger
 from src.memory_graph.manager import MemoryManager
@@ -15,56 +14,56 @@ from src.memory_graph.manager import MemoryManager
 logger = get_logger(__name__)
 
 # 全局 MemoryManager 实例
-_memory_manager: Optional[MemoryManager] = None
+_memory_manager: MemoryManager | None = None
 _initialized: bool = False
 
 
 async def initialize_memory_manager(
-    data_dir: Optional[Path | str] = None,
-) -> Optional[MemoryManager]:
+    data_dir: Path | str | None = None,
+) -> MemoryManager | None:
     """
     初始化全局 MemoryManager
-    
+
     直接从 global_config.memory 读取配置
-    
+
     Args:
         data_dir: 数据目录（可选，默认从配置读取）
-        
+
     Returns:
         MemoryManager 实例，如果禁用则返回 None
     """
     global _memory_manager, _initialized
-    
+
     if _initialized and _memory_manager:
         logger.info("MemoryManager 已经初始化，返回现有实例")
         return _memory_manager
-    
+
     try:
         from src.config.config import global_config
-        
+
         # 检查是否启用
-        if not global_config.memory or not getattr(global_config.memory, 'enable', False):
+        if not global_config.memory or not getattr(global_config.memory, "enable", False):
             logger.info("记忆图系统已在配置中禁用")
             _initialized = False
             _memory_manager = None
             return None
-        
+
         # 处理数据目录
         if data_dir is None:
-            data_dir = getattr(global_config.memory, 'data_dir', 'data/memory_graph')
+            data_dir = getattr(global_config.memory, "data_dir", "data/memory_graph")
         if isinstance(data_dir, str):
             data_dir = Path(data_dir)
-        
+
         logger.info(f"正在初始化全局 MemoryManager (data_dir={data_dir})...")
-        
+
         _memory_manager = MemoryManager(data_dir=data_dir)
         await _memory_manager.initialize()
-        
+
         _initialized = True
         logger.info("✅ 全局 MemoryManager 初始化成功")
-        
+
         return _memory_manager
-        
+
     except Exception as e:
         logger.error(f"初始化 MemoryManager 失败: {e}", exc_info=True)
         _initialized = False
@@ -72,24 +71,24 @@ async def initialize_memory_manager(
         raise
 
 
-def get_memory_manager() -> Optional[MemoryManager]:
+def get_memory_manager() -> MemoryManager | None:
     """
     获取全局 MemoryManager 实例
-    
+
     Returns:
         MemoryManager 实例，如果未初始化则返回 None
     """
     if not _initialized or _memory_manager is None:
         logger.warning("MemoryManager 尚未初始化，请先调用 initialize_memory_manager()")
         return None
-    
+
     return _memory_manager
 
 
 async def shutdown_memory_manager():
     """关闭全局 MemoryManager"""
     global _memory_manager, _initialized
-    
+
     if _memory_manager:
         try:
             logger.info("正在关闭全局 MemoryManager...")