Each section is a board panel: give it a title, add stops to it below,
and optionally list lines in display order (e.g. 14, 14R, 49; BART lines by
color word, e.g. Yellow). Blank = all lines, soonest first.
“Add” merges both directions into one panel; “Add split by direction” creates one section per platform (Northbound / Southbound).