fix(backend): 统一为本地及MCP动态工具注入handle_tool_error容错

- 在 mcp_service 的 get_mcp_tools 加载出口全局设置 tool.handle_tool_error = True
- 在 toolkits registry 的 @tool 装饰器中对本地工具默认开启 handle_tool_error = True
- 修复因 MCP/本地工具内部执行出错抛出 ToolException 时击穿流服务导致 crash 的 bug
- 新增两个单元测试进行完备性验证

backend/package/yuxi/agents/toolkits/registry.py

@@ -89,6 +89,7 @@ def tool(
         )
 
         # 自动收集工具实例
+        tool_obj.handle_tool_error = True
         _all_tool_instances.append(tool_obj)
 
         return tool_obj

backend/package/yuxi/services/mcp_service.py

@@ -275,6 +275,8 @@ async def get_mcp_tools(
                 if tool.metadata is None:
                     tool.metadata = {}
                 tool.metadata["id"] = unique_id
+                # 开启错误处理，防止工具调用抛出 ToolException 时击穿服务
+                tool.handle_tool_error = True
                 all_processed_tools.append(tool)
 
             if cache:

backend/test/unit/services/test_mcp_service.py

@@ -112,3 +112,27 @@ async def test_get_tools_from_all_servers_loads_names_from_db_once(monkeypatch):
         ("alpha", server_configs),
         ("beta", server_configs),
     ]
+
+
+async def test_get_mcp_tools_sets_handle_tool_error(monkeypatch):
+    mcp_service.clear_mcp_cache()
+
+    config = {"transport": "stdio", "command": "demo-tool", "disabled_tools": []}
+
+    async def fake_get_enabled_mcp_server_config(server_name: str, db=None):
+        del db
+        return config
+
+    async def fake_get_mcp_client(server_configs):
+        tool = SimpleNamespace(name="demo_tool", metadata={})
+        return _FakeClient([tool])
+
+    monkeypatch.setattr(mcp_service, "get_enabled_mcp_server_config", fake_get_enabled_mcp_server_config)
+    monkeypatch.setattr(mcp_service, "get_mcp_client", fake_get_mcp_client)
+
+    tools = await mcp_service.get_mcp_tools("demo")
+    assert len(tools) == 1
+    assert tools[0].handle_tool_error is True
+
+    mcp_service.clear_mcp_cache()
+

backend/test/unit/toolkits/test_tool_registry.py

@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+from yuxi.agents.toolkits.registry import tool
+
+
+def test_tool_decorator_sets_handle_tool_error():
+    """测试通过 @tool 装饰器注册的工具是否自动设置了 handle_tool_error 为 True"""
+
+    @tool(
+        category="test",
+        display_name="测试工具",
+        description="这是一个单元测试工具",
+    )
+    def my_test_tool(arg: str) -> str:
+        return f"hello {arg}"
+
+    assert my_test_tool.name == "my_test_tool"
+    assert my_test_tool.handle_tool_error is True