[Jord-JD]

Summary

• migrate the runtime from phpseclib 2.x to the maintained 3.x line without raising PHP 7.2
• add pre-authentication host-key pinning with standard OpenSSH SHA-256/MD5 fingerprints and raw host-key access
• support passphrase-protected private key files and strings
• use SFTP for uploads and downloads, rejecting remote symlinks during recursive downloads
• expose command exit status, success, and timeout state while preserving raw/trimmed output APIs
• apply configured timeouts to connection/authentication as well as later operations
• validate hostnames, usernames, ports, timeouts, commands, paths, and key inputs explicitly
• update the real OpenSSH integration matrix to PHP 7.2 and PHP 8.5 with plain keys, encrypted keys, passwords, host pinning, transfers, and command failures
• document security usage, fingerprint formats, key passphrases, timeouts, SFTP safety, compatibility, and v5 migration

SemVer

This is prepared for v5.0.0 because the phpseclib runtime major changes, uploads move from SCP to SFTP, and all fingerprints are corrected to hash the complete SSH wire key.

Validation

• composer.json parsed as valid JSON
• git diff --check
• GitHub Actions provisions a real local OpenSSH server and is the executable PHP/integration gate