`Controls/SegmentMeter` draws a 24-segment ladder in ONE OnRender pass — no per-segment elements
updating on the UI thread, which is the difference between a meter and a UI thread tax. Level and
peak are display fractions (what was MEASURED), never gain settings; vertical for the bay ladders,
horizontal for the master strip.
Bands come from `Helpers/MeterScale` (nominal/caution/peak, DESIGN.md thresholds) and live as
dependencies of the control, so the painting logic is pure and testable: the band a segment paints
is the level it measured. Brushes resolve from the theme tokens via SetResourceReference, so the
ladder cannot drift from DESIGN.md.
Peak-hold is the reason the header exists: a bar that follows the moment hides clipping, and
clipping is the one audio fault that cannot be fixed after the stream.
Guard: MeterScaleTests — band edges (inclusive at −12 and −3, as the standard states the ranges),
the −60…0 display scale, and peak-hold rising instantly then decaying at 0.35/s.
