L-w3: complete three-accent pastel repalette + REAPER-grey neutrals

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.

src/draw_kit.cpp

@@ -208,7 +208,7 @@ void drawButton(LICE_IBitmap* bmp, const KitButtonBox& button, const char* label
     const int radius = b.height >= 20 ? 5 : (b.height >= 12 ? 3 : 2);
     const KitColor borderCol =
         (state == InteractionState::Active || state == InteractionState::Focus)
-            ? roleColor(Role::Accent)
+            ? roleColor(Role::AccentPrimary)
             : roleColor(Role::LineHairline);
     LICE_RoundRect(bmp, static_cast<float>(b.x), static_cast<float>(b.y),
                    static_cast<float>(b.width - 1), static_cast<float>(b.height - 1),
@@ -238,7 +238,7 @@ void drawSlider(LICE_IBitmap* bmp, const SliderGeometry& geom, InteractionState
                 ? InteractionState::Hover
                 : InteractionState::Active;
         KitColor top, bottom;
-        gradientPair(roleColorState(Role::Accent, fillState), top, bottom);
+        gradientPair(roleColorState(Role::AccentPrimary, fillState), top, bottom);
         fillGradient(bmp, geom.filled, top, bottom);
     }
 
@@ -281,7 +281,7 @@ void drawWaveform(LICE_IBitmap* bmp, const KitBox& box, const Envelope& env) {
     if (!bmp || box.empty()) return;
 
     const LICE_pixel midCol = toLice(roleColor(Role::LineHairline));
-    const LICE_pixel waveCol = toLice(roleColor(Role::Accent));
+    const LICE_pixel waveCol = toLice(roleColor(Role::AccentPrimary));
 
     if (env.empty()) {
         const int midY = box.y + box.height / 2;