Use block characters (█/░) with accent coloring for scrollbar thumb/track
instead of box-drawing chars that blend with panel borders. Auto-derive
scrollbar from content overflow in titledPanelH. Add scrollbar to logs
and maintenance bottom panels.
Opt-in scrollbar track on the right border edge when totalItems > bodyH.
Thin track (│) with muted thumb (┃) showing viewport position.
Monitors panel passes len(sites) to enable it. Detail and fullscreen
panels pass 0 to opt out. Any panel can opt in via the totalItems param.