fix(db): 修复数据库会话获取失败时的处理逻辑

在 `db_query` 和 `db_save` 函数中，增加了对数据库会话（session）获取失败的检查。当无法获取会话时，记录错误日志并返回 None 或空列表，避免了后续操作因会话为空而引发的异常。

同时，修复了 `proactive_thinker_executor` 中因数据库查询返回 None 而导致处理 `action_history` 时出错的问题。

src/common/database/sqlalchemy_database_api.py

@@ -124,6 +124,10 @@ async def db_query(
             raise ValueError("query_type must be 'get', 'create', 'update', 'delete' or 'count'")
 
         async with get_db_session() as session:
+            if not session:
+                logger.error("[SQLAlchemy] 无法获取数据库会话")
+                return None if single_result else []
+
             if query_type == "get":
                 query = select(model_class)
 
@@ -221,7 +225,7 @@ async def db_query(
                 # 删除记录
                 affected_rows = 0
                 for record in records_to_delete:
-                    session.delete(record)
+                    await session.delete(record)
                     affected_rows += 1
 
                 return affected_rows
@@ -274,6 +278,9 @@ async def db_save(
     """
     try:
         async with get_db_session() as session:
+            if not session:
+                logger.error("[SQLAlchemy] 无法获取数据库会话")
+                return None
             # 如果提供了key_field和key_value，尝试更新现有记录
             if key_field and key_value is not None:
                 if hasattr(model_class, key_field):

src/plugins/built_in/proactive_thinker/proactive_thinker_executor.py

@@ -128,7 +128,9 @@ class ProactiveThinkerExecutor:
             limit=3,
             order_by=["-time"]
         )
-        action_history_context = "\n".join([f"- {a['action_data']}" for a in action_history]) if action_history else "无"
+        action_history_context = "无"
+        if isinstance(action_history, list):
+            action_history_context = "\n".join([f"- {a['action_data']}" for a in action_history if isinstance(a, dict)]) or "无"
 
         return {
             "person_id": person_id,