692a385f5b
A stalled/failed QUIC handshake gave no hint whether the socket connected over IPv4 or fell into the ::1 blackhole. The HandshakeFailed messages now carry `socket=<addr>:<port> sni=<host>` so the failure itself shows which address resolvePreferIpv4 picked. https://claude.ai/code/session_01PoQupfdoKU3ryQwLwTeXeM