Multiplexers

• tmux — one window per repository named after it, plus a shared window for the branch directory when there are several repos. Inside tmux the current client is switched; outside, ws hands the terminal to attach-session.
• herdr — one workspace per branch labelled like the tmux session, one tab per repository plus one for the branch directory, mirroring the tmux windows. [mux.herdr] layout = "panes" puts them side by side in a single tab instead, and split_direction then says where each one goes. Command shapes are verified against herdr 0.9; ids are read back from the JSON .result rather than constructed.
• none — prints the branch directory instead.

backend = "auto" picks whichever one ws is running inside, then whichever is installed.