配置文件增加UTF8编码格式支持，以免解析中文时出现问题

backend/app/engine/tools/__init__.py

@@ -1,10 +1,9 @@
-import os
-import yaml
-import json
 import importlib
-from cachetools import cached, LRUCache
-from llama_index.core.tools.tool_spec.base import BaseToolSpec
+import os
+
+import yaml
 from llama_index.core.tools.function_tool import FunctionTool
+from llama_index.core.tools.tool_spec.base import BaseToolSpec
 
 
 class ToolType:
@@ -46,7 +45,7 @@ class ToolFactory:
     def from_env() -> list[FunctionTool]:
         tools = []
         if os.path.exists("config/tools.yaml"):
-            with open("config/tools.yaml", "r") as f:
+            with open("config/tools.yaml", "r", encoding='UTF-8') as f:
                 tool_configs = yaml.safe_load(f)
                 if tool_configs != None and len(tool_configs.items()) != 0:
                     for tool_type, config_entries in tool_configs.items():