test: dev extra 补 pytest-asyncio，防新环境 async 测试假绿

Co-Authored-By: Claude <noreply@anthropic.com>

pyproject.toml

@@ -13,7 +13,7 @@ dependencies = [
 ]
 
 [project.optional-dependencies]
-dev = ["pytest>=8"]
+dev = ["pytest>=8", "pytest-asyncio"]
 mcp = ["mcp>=1.10,<2"]
 
 [project.scripts]