refactor: 优化参数传递，清理导入样式

tests/inference/conftest.py

@@ -1,8 +1,10 @@
 """Shared fixtures for inference tests."""
 
-import pytest
 from unittest.mock import MagicMock, patch
+
+import pytest
 from fastapi.testclient import TestClient
+
 from astrai.inference.server import app
 
 

tests/inference/test_server.py

@@ -1,9 +1,6 @@
 """Unit tests for the inference HTTP server."""
 
 import pytest
-from unittest.mock import MagicMock, patch
-from fastapi.testclient import TestClient
-from astrai.inference.server import app
 
 
 def test_health_no_model(client, monkeypatch):