web: move WHITE/BLACK onto the WB tab as per-channel points

LIGHT already spends its slope budget on the tone knees, so the two end
points were doing nothing a tone knob could not. On WB they act on each
channel's own distance from the end: the darker channel of a shadow and
the brighter channel of a highlight move most, which neutralises a cast
at the toe and the shoulder. Both shuffles stay cubic in the channel
value, so every channel's curve is still monotonic (>= 0.46).

docker/frontend/shared/utils/paramDefs.ts

@@ -105,30 +105,6 @@ export const PARAM_DEFS: {
       get: (a) => a.shadow ?? 0,
       set: (v) => ({ shadow: v }),
     },
-    {
-      // The end points of the tone curve: WHITE lifts/crushes the top, BLACK the
-      // toe. Same range as the CREATE form's rows, so a look round-trips.
-      key: 'whites',
-      label: 'WHITE',
-      min: -10,
-      max: 10,
-      step: 1,
-      defaultValue: 0,
-      display: sign,
-      get: (a) => a.whites ?? 0,
-      set: (v) => ({ whites: v }),
-    },
-    {
-      key: 'blacks',
-      label: 'BLACK',
-      min: -10,
-      max: 10,
-      step: 1,
-      defaultValue: 0,
-      display: sign,
-      get: (a) => a.blacks ?? 0,
-      set: (v) => ({ blacks: v }),
-    },
   ],
   wb: [
     {
@@ -153,6 +129,32 @@ export const PARAM_DEFS: {
       get: (a) => a.tint ?? 0,
       set: (v) => ({ tint: v }),
     },
+    {
+      // The two points live on WB, not on LIGHT: they shift each channel's own
+      // end of the ramp, which balances a cast at the toe and the shoulder
+      // rather than adding another tone knob. Same range as the CREATE form's
+      // rows, so a look round-trips.
+      key: 'whites',
+      label: 'WHITE',
+      min: -10,
+      max: 10,
+      step: 1,
+      defaultValue: 0,
+      display: sign,
+      get: (a) => a.whites ?? 0,
+      set: (v) => ({ whites: v }),
+    },
+    {
+      key: 'blacks',
+      label: 'BLACK',
+      min: -10,
+      max: 10,
+      step: 1,
+      defaultValue: 0,
+      display: sign,
+      get: (a) => a.blacks ?? 0,
+      set: (v) => ({ blacks: v }),
+    },
   ],
   filters: [
     {