refactor: 优化类型检查导入和代码格式，提升可读性

Change-Id: I2df17dbabb8bc6112342daf55bd8f7a7652fee6b
Signed-off-by: OhYee <oyohyee@oyohyee.com>

Author: OhYee

agentrun/integration/utils/tool.py

@@ -35,6 +35,7 @@
     Set,
     Tuple,
     Type,
+    TYPE_CHECKING,
 )
 
 from pydantic import (
@@ -45,7 +46,9 @@
     ValidationError,
 )
 
-from agentrun.toolset import ToolSet
+if TYPE_CHECKING:
+    from agentrun.toolset import ToolSet
+
 from agentrun.utils.log import logger
 
 # Tool name constraints for external providers like OpenAI

agentrun/toolset/toolset.py

@@ -22,7 +22,6 @@
 from agentrun.utils.log import logger
 from agentrun.utils.model import BaseModel
 
-from .api.openapi import OpenAPI
 from .model import (
     MCPServerConfig,
     SchemaType,