MEM-009: TCP/UDP socket fd leaked on bind failure (abc/TCP.c, abc/UDP.c)

Now: DONE

In both TCPListen and UDPBind the resolve loop opens a socket, then on a failing bind() the error branch traces, frees the addrinfo, and returns the failure code without close(sfd); the loop's normal close(sfd) is unreachable past the early return, so every bind failure (port in use, permission denied) leaks a descriptor. The goal is to close the socket on the failure path.

Issues

Identical leak in two siblings.

abc/TCP.c:50-55 — bind() fails → return TCPFAIL with sfd still open; close(sfd) at :58 never reached.
abc/UDP.c:19-24 — same shape: bind() fails → return UDPFAIL, close(sfd) at :27 never reached.

Blockers

None.

Planned

Close before failing.

Repro first: bind to an in-use port and assert the fd count does not grow across calls.
close(sfd) before the early return in each bind-failure branch (or close(sfd); continue; and fail only after the loop).