fix circular imports

api/models/model.py

@@ -9,7 +9,6 @@ from typing import TYPE_CHECKING, Any, Literal, Optional, cast
 from core.plugin.entities.plugin import GenericProviderID
 from core.tools.entities.tool_entities import ToolProviderType
 from core.tools.signature import sign_tool_file
-from services.plugin.plugin_service import PluginService
 
 if TYPE_CHECKING:
     from models.workflow import Workflow
@@ -169,6 +168,7 @@ class App(Base):
     @property
     def deleted_tools(self) -> list:
         from core.tools.tool_manager import ToolManager
+        from services.plugin.plugin_service import PluginService
 
         # get agent mode tools
         app_model_config = self.app_model_config