Add --ssh option and improve SSH TTY handling
Add a --ssh / -s flag to `start` to connect and open a shell
automatically.
Treat Ctrl+K (0x0b) as a local-only escape in raw TTY mode to teardown
immediately without forwarding to the remote. Treat an SSE close with no
error message as a graceful shell exit (exit code 0) rather than a
connection error. Bump CLI version to 0.2.5.