Cowrie was exposing an SSH daemon on port 22 alongside the telnet service
even when COWRIE_SSH_ENABLED=false, contaminating deployments that did not
request an SSH service.
New implementation mirrors the SSH service pattern:
- busybox telnetd in foreground mode on port 23
- /bin/login for real PAM authentication (brute-force attempts logged)
- rsyslog RFC 5424 bridge piped to stdout for Docker log capture
- Configurable root password and hostname via env vars
- No Cowrie dependency
