Decouples the keyboard strip's mid stop from accent/secondary, which the
deep-teal darkening had inverted. Adds overlay/trace (#816AA6), the first
value to clear 3:1 against the waveform. Replaces the frozen-premise test.
Loop span/markers and the envelope overlay trace shared tertiary purple in the same
overlay rect. Loop markers now draw secondary; envelope overlay keeps tertiary.
Adds a theme-level distinctness regression guard.
Trigger's fade pair folds into the AHD (and goes live); the release anchors right;
Preserve rings its synthetic tail out instead of cutting it. Payload v10.
Finish roleColor/roleColorState for the three-accent enum, re-map every
Accent consumer (primary leads live; Pool/Banks titles categorical
secondary/tertiary), make spectralColor a lime->teal->purple three-stop
sweep, and re-lock the WCAG-floor tests on the grey ladder.
daniel