rusty-autossh 0.1.0

Keep an SSH tunnel alive across drops — a Rust port of Carson Harding's `autossh 1.4g` SSH connection supervisor. Tokio-based supervisor, `-M <port>` monitor-port heartbeat (or `-M 0` exit-only respawn), `AUTOSSH_*` env-var surface incl. `AUTOSSH_MESSAGE` byte-identical wire format, Unix `-f` daemonize + Windows `DETACHED_PROCESS` analogue, SIGTERM/SIGUSR1/SIGHUP handling on Unix, byte-equal Strict-mode upstream compatibility, and a typed library API.