fix: preserve IO::Async accepted sockets and binary payloads

[fglock]

Summary

• preserve accepted socket ownership across callback argument assignment
• preserve binary octets through internal pipes used by IO::Async channels
• add focused accepted-socket and Storable pipe regressions

Validation

• make
• system Perl, JVM, and interpreter runs of both focused regressions
• IO::Async 0.805 listener regression reaches the previously failing peer-address assertion on both backends

The remaining IO::Async listener test process phase is environment-limited by fork resource exhaustion.