Fix Silk background freezing on parameter change

[Copilot]

The Silk background (R3F) froze whenever a parameter was changed in Background Studio instead of applying the update and continuing the animation.

Cause

uniforms was rebuilt (new object reference) on every prop change because all props were in the useMemo dependency array. Handing a fresh uniforms object to <shaderMaterial> each render makes R3F swap the material's uniforms out from under the running useFrame loop, stalling the animation.

Changes

• Stable uniforms: create the uniforms object once (useMemo(..., [])) so the reference passed to <shaderMaterial> never changes.
• Live sync: mutate the existing uniform .value fields in a useEffect when props change, so updates apply without remounting the material. Color uses setRGB(r, g, b) (matching the original new Color(r, g, b), since Color.set takes a single arg).
• Applied identically across all four variants: content (JS/CSS), tailwind (JS/TW), ts-default, ts-tailwind.
• Synced the embedded source in the generated public/r/Silk-{JS,TS}-{CSS,TW}.json registry files.

const uniforms = useMemo(() => ({ /* ...initial values... */, uTime: { value: 0 } }), []);

useEffect(() => {
  uniforms.uSpeed.value = speed;
  uniforms.uScale.value = scale;
  uniforms.uNoiseIntensity.value = noiseIntensity;
  uniforms.uColor.value.setRGB(...hexToNormalizedRGB(color));
  uniforms.uRotation.value = rotation;
}, [speed, scale, noiseIntensity, color, rotation, uniforms]);

• Fixes [BUG]: Background "Silk" freezing in Background Studio on parameter change. #1010