Scans RAW output (multiplexer escapes are themselves ANSI; never strip first) for tmux markers (DCS passthrough, focus-reporting, window-title with tmux marker) and screen markers (DCS, screen-OSC). Detected → tmux/screen at 0.85; otherwise → none at 0.55. Skips emission entirely when no commands — silence on a pure-echo or empty session, per the smoke gates. When both detected (nested mux), prefer tmux.