The nREPL server bound its loopback socket through libc process symbols,
which don't carry the socket entry points on Windows — they live in
ws2_32.dll and aren't in joltc.exe's export table, so --nrepl-server died
with "no entry for socket". Load ws2_32 before the foreign bindings there,
call WSAStartup once, and use Winsock's closesocket and int-typed
recv/send. Also fix SOL_SOCKET/SO_REUSEADDR, which the old macos-only
check got wrong on Windows.
Bake a version string into the self-contained binary at build time (from
$JOLT_VERSION, else git describe) and expose it via jolt.host/jolt-version:
--version / -V print it, and it shows in --help, the repl banner, and the
nREPL startup line. Dev runs off bin/joltc read it from git describe.
Add -e to the help output.