test_refresh_skew_rejects_negative_and_boolean omitted the required
token_url, so McpOAuthConfig(refresh_skew_seconds=-1) failed validation
on the missing field alone -- deleting the ge=0 bound and the boolean
validator would leave the test green. Pass token_url (the same URL the
refresh_skew_seconds=0 boundary test uses) so only the guards can
satisfy pytest.raises; verified by stripping both guards from
extensions_config.py, which now fails exactly the two parametrized
cases, and restoring them, which returns the suite to 42 passed.
Also move SandboxOwnershipConfig up beside the other config imports
and drop the redundant in-test `import pytest` (review nits on #6026).
Generated-by: ZCode (GLM, coding agent)
Co-authored-by: liwenjie200543 <liwenjie200543@users.noreply.github.com>