Width (px) reserved on the LEFT for the optional secondary price axis
(B2). 0 when no indicator is bound to the left scale — in that case
chartLeft stays at 0 and the layout/render is identical to before.
When > 0, chartLeft is shifted right by this much to make room.
Bottom of the last sub-pane band (== height − timeAxisHeight).
When no sub-panes are active this equals chartBottom.
Top of the first sub-pane band (== chartBottom).
Number of pane-placement indicator bands stacked under the main chart.
Bottom of the candle / price area. When sub-pane indicators are present this value sits ABOVE the time axis with one or more indicator panes between it and
paneAreaBottom.