fix: set asyncio_default_fixture_loop_scope to silence deprecation warning

Future pytest-asyncio versions will default async fixture loop scope to
"function". Set it explicitly to avoid surprises on upgrade.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: claude

pyproject.toml

@@ -33,6 +33,9 @@ type_check = ["pyright~=1.1"]
 nox = ["nox~=2026.2", "nox-uv~=0.7"]
 
 
+[tool.pytest.ini_options]
+asyncio_default_fixture_loop_scope = "function"
+
 [tool.ruff.lint.per-file-ignores]
 "*/__init__.py" = ["F401", "F403"]