feat: persistent help tab with keybindings cheat sheet

- Colorized reference card auto-redraws on resize
- Ctrl-A ? jumps to help tab (recreates if closed)
- Fixed tmux config syntax error in capture/logging bindings

sethmux-start.sh

@@ -11,6 +11,7 @@ tmux new-session -d -s "$SESSION" -n "code" -x 120 -y 40
 tmux new-window -t "$SESSION" -n "git"
 tmux new-window -t "$SESSION" -n "run"
 tmux new-window -t "$SESSION" -n "logs"
+tmux new-window -t "$SESSION" -n "help" "/opt/sethmux/sethmux-help.sh"
 tmux select-window -t "$SESSION:1"
 
 # Ensure logs dir exists