Open a byte stream to a port inside a sandbox, over WebSocket: what SSH, SCP and port forwarding use
GET /v1/sandboxes/{sandbox}/tunnel
In this build: Works on the simulator or a real VM.
Scope: ssh
CLI: harebox tunnel
port
Server-sent events. Each event's id is a resume cursor. Send Upgrade: websocket for WebSocket framing.
Errors follow one format.

