Effect's RPC server swallows the socket's close error, so a client close
left only the HTTP 101 in the log. The upgraded socket now records the
close code and reason before that, and each connection ends with one
`WebSocket closed` line: how it ended, code, reason, duration, last
inbound frame age, session, surface and address.

Adapted from the WsConnectionLog in #24285 by only21mil.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>