test: Pin pytest-asyncio to strict mode

All 51 async tests are explicitly marked with @pytest.mark.asyncio,
so they already match strict mode. Pin asyncio_mode = "strict" to
catch any future async test that forgets the marker rather than
silently relying on auto-detection.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jsonbailey

packages/sdk/server-ai/pyproject.toml

@@ -67,6 +67,7 @@ non_interactive = true
 [tool.pytest.ini_options]
 addopts = ["-ra"]
 testpaths = ["tests"]
+asyncio_mode = "strict"
 
 [tool.isort]
 profile = "black"