This hits a real pain point. I keep three or four agents running in seperate tmux sessions and the part that always got me is reaching them from my phone when I step away, right now I just inject into the active session over ssh which is clunky. Love that you kept it as plain tmux so you can still attach the normal way, that is the bit that would make me actually trust it over a custom protocol. One thing I am curious about, when an agent dumps a big wall of output at once does xterm.js over SSE keep up or does it lag behind? Might spin it up on my mini pc this weekend.