fix: auto-fix code issues (cron)

- 修复隐式 Optional 类型注解 (RUF013)
- 修复不必要的赋值后返回 (RET504)
- 优化列表推导式 (PERF401)
- 修复未使用的参数 (ARG002)
- 清理重复导入
- 优化异常处理

backend/performance_manager.py

@@ -444,7 +444,8 @@ class CacheManager:
                     "memory_size_bytes": self.current_memory_size,
                     "max_memory_size_bytes": self.max_memory_size,
                     "memory_usage_percent": round(
-                        self.current_memory_size / self.max_memory_size * 100, 2,
+                        self.current_memory_size / self.max_memory_size * 100,
+                        2,
                     ),
                     "cache_entries": len(self.memory_cache),
                 },
@@ -548,11 +549,13 @@ class CacheManager:
 
         # 预热项目知识库摘要
         entity_count = conn.execute(
-            "SELECT COUNT(*) FROM entities WHERE project_id = ?", (project_id,),
+            "SELECT COUNT(*) FROM entities WHERE project_id = ?",
+            (project_id,),
         ).fetchone()[0]
 
         relation_count = conn.execute(
-            "SELECT COUNT(*) FROM entity_relations WHERE project_id = ?", (project_id,),
+            "SELECT COUNT(*) FROM entity_relations WHERE project_id = ?",
+            (project_id,),
         ).fetchone()[0]
 
         summary = {
@@ -757,11 +760,13 @@ class DatabaseSharding:
             source_conn.row_factory = sqlite3.Row
 
             entities = source_conn.execute(
-                "SELECT * FROM entities WHERE project_id = ?", (project_id,),
+                "SELECT * FROM entities WHERE project_id = ?",
+                (project_id,),
             ).fetchall()
 
             relations = source_conn.execute(
-                "SELECT * FROM entity_relations WHERE project_id = ?", (project_id,),
+                "SELECT * FROM entity_relations WHERE project_id = ?",
+                (project_id,),
             ).fetchall()
 
             source_conn.close()
@@ -1061,7 +1066,9 @@ class TaskQueue:
                     task.status = "retrying"
                     # 延迟重试
                     threading.Timer(
-                        10 * task.retry_count, self._execute_task, args=(task_id,),
+                        10 * task.retry_count,
+                        self._execute_task,
+                        args=(task_id,),
                     ).start()
                 else:
                     task.status = "failed"
@@ -1163,7 +1170,10 @@ class TaskQueue:
             return self.tasks.get(task_id)
 
     def list_tasks(
-        self, status: str | None = None, task_type: str | None = None, limit: int = 100,
+        self,
+        status: str | None = None,
+        task_type: str | None = None,
+        limit: int = 100,
     ) -> list[TaskInfo]:
         """列出任务"""
         conn = sqlite3.connect(self.db_path)
@@ -1635,7 +1645,7 @@ def cached(
                 cache_key = key_func(*args, **kwargs)
             else:
                 # 默认使用函数名和参数哈希
-                key_data = f"{func.__name__}:{str(args)}:{str(kwargs)}"
+                key_data = f"{func.__name__}:{args!s}:{kwargs!s}"
                 cache_key = f"{key_prefix}:{hashlib.md5(key_data.encode()).hexdigest()[:16]}"
 
             # 尝试从缓存获取
@@ -1754,12 +1764,16 @@ _performance_manager = None
 
 
 def get_performance_manager(
-    db_path: str = "insightflow.db", redis_url: str | None = None, enable_sharding: bool = False,
+    db_path: str = "insightflow.db",
+    redis_url: str | None = None,
+    enable_sharding: bool = False,
 ) -> PerformanceManager:
     """获取性能管理器单例"""
     global _performance_manager
     if _performance_manager is None:
         _performance_manager = PerformanceManager(
-            db_path=db_path, redis_url=redis_url, enable_sharding=enable_sharding,
+            db_path=db_path,
+            redis_url=redis_url,
+            enable_sharding=enable_sharding,
         )
     return _performance_manager