Configure ZSH for creating tmux sessions and auto-attaching windows for sync between mobile + desktop

.zshrc

# Auto-start tmux (attach to existing session or create new)
if command -v tmux &> /dev/null && [ -z "$TMUX" ]; then
  if [ -z "$SSH_CLIENT" ]; then
    # Local terminal: create new window in last used directory
    DIR=$(tmux showenv LAST_DIR 2>/dev/null | cut -d= -f2)
    tmux new-session -t main \; new-window -c "${DIR:-$HOME}" 2>/dev/null || tmux new -s main
  else
    # SSH (Termius): just attach to existing session
    tmux attach -t main 2>/dev/null || tmux new -s main
  fi
fi

# Track current directory for new tmux windows
_update_tmux_dir() {
  if [ -n "$TMUX" ]; then
    tmux setenv LAST_DIR "$PWD"
  fi
}
precmd_functions+=(_update_tmux_dir)