We can't do any file syscalls anyway because of the reduction of pledges, so we might as well lock the veil anyway.
This avoids getting into the awkward situation where the socket is still part-owned by main() in multi-instance service. Also it just reads nicer.
And moved everything to AudioServer namespace
It didn't feel right to have a "DHCPClient" in a "Servers" directory. Rename this to Services to better reflect the type of programs we'll be putting in there.