Winsock never makes a socket whose connect failed writable; the failure
shows in select's exception set, with the reason in SO_ERROR. The poll
now checks both, and SO_ERROR on a writable socket too, which is where
other systems put a refusal.
Windows still retries a refused connect for about a second before
reporting it, far longer than a PSP at the tests' 800% speed, so
pair/basic is a known P2P failure on Windows.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
