- SSH key pairs are generated with ssh-key (Ed25519/ECDSA P-256/RSA) and
encrypted in-process, so the passphrase no longer appears as an ssh-keygen
command-line argument visible in the process list.
- open_tunnel's loopback bridge checks the accepted peer is our own client
socket, so a local process racing for the ephemeral port can't be spliced
into the IRC/VNC SSH tunnel.
- run_command caps buffered output at 1 MiB; local-forward abort handles are
pruned as connections finish; SOCKS5 host/credential lengths over 255 bytes
are rejected instead of being truncated into a malformed request.