Match the ZXB1 sub-chart formula: each brick spans between yesterday's
and today's brick value via a stacked range bar — rising bricks are
hollow red (solid on strong_red), falling bricks solid green. The chart
API now also returns brick_strong_red per point.
Add an optional brick_chart series to the selection chart API, computed
from the shared gold-brick formula when strategy=gold_brick, and render
a fourth grid with red/green brick bars between the volume and J grids.