Function isTmuxControlModeEnvHeuristic

src/utils/fullscreen.ts:29–36

* Env-var heuristic for iTerm2's tmux integration mode (`tmux -CC` / `tmux -2CC`). * * In `-CC` mode, iTerm2 renders tmux panes as native splits — tmux runs * as a server (TMUX is set) but iTerm2 is the actual terminal emulator * for each pane, so TERM_PROGRAM stays `iTerm.app` and TERM is iTerm

()

 * authoritative backstop. Kept as a zero-subprocess fast path.
 */
function isTmuxControlModeEnvHeuristic(): boolean {
  if (!process.env.TMUX) return false
  if (process.env.TERM_PROGRAM !== 'iTerm.app') return false
  // Belt-and-suspenders: in regular tmux TERM is screen-* or tmux-*;
  // in -CC mode iTerm2 sets its own TERM (xterm-*).
  const term = process.env.TERM ?? ''
  return !term.startsWith('screen') && !term.startsWith('tmux')
}

/**
 * Sync one-shot probe: asks tmux directly whether this client is in control