fix: declare sniffio as a direct runtime dependency

pyproject.toml

@@ -12,6 +12,7 @@ pydantic = ">=1.9.0,<3.0"
 pydantic-core = ">=2.14.6"
 cachetools = ">=4.2.2"
 pyjwt = "~=2.8.0"
+sniffio = ">=1.3.0"
 
 
 [tool.poetry.group.test.dependencies]

tests/installation/README.md

@@ -0,0 +1,15 @@
+# Installed-package smoke tests
+
+Run these checks in a fresh environment after building and installing the wheel,
+without installing test or development extras. This catches runtime dependencies
+that an existing development environment can accidentally provide.
+
+```sh
+python -m pip wheel . --no-deps --wheel-dir dist
+python -m venv /tmp/zhipuai-install-test
+/tmp/zhipuai-install-test/bin/python -m pip install dist/zhipuai-*.whl
+/tmp/zhipuai-install-test/bin/python -I tests/installation/test_installed_sdk.py -v
+```
+
+The isolated interpreter imports the installed package rather than the source
+checkout. The tests create no API requests and require only runtime dependencies.

tests/installation/test_installed_sdk.py

@@ -0,0 +1,27 @@
+"""Run with ``python -I`` after installing a wheel in a clean environment."""
+
+import asyncio
+import unittest
+
+
+class InstalledSDKTests(unittest.TestCase):
+	def test_public_sdk_import(self):
+		from zhipuai import ZhipuAI
+
+		with ZhipuAI(api_key='test-key') as client:
+			self.assertFalse(client.is_closed())
+		self.assertTrue(client.is_closed())
+
+	def test_async_library_detection(self):
+		from zhipuai.core._utils import get_async_library
+
+		self.assertEqual(get_async_library(), 'false')
+
+		async def detect():
+			return get_async_library()
+
+		self.assertEqual(asyncio.run(detect()), 'asyncio')
+
+
+if __name__ == '__main__':
+	unittest.main()