feat: add Anthropic partner icon

Adds the Anthropic logo to the partner-node icon set so nodes with
category 'api node/text/Anthropic' (e.g. the Claude node from
Comfy-Org/ComfyUI#13867) render the correct provider badge in the
node library.

- packages/design-system/src/icons/anthropic.svg (auto-discovered)
- categoryUtil.ts: register brand coral (#D97757) border color

packages/design-system/src/icons/anthropic.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="currentColor" fill-rule="evenodd"><title>Anthropic</title><path d="M13.827 3.52h3.603L24 20h-3.603l-6.57-16.48zm-7.258 0h3.767L16.906 20h-3.674l-1.343-3.461H5.017l-1.344 3.46H0L6.57 3.522zm4.132 9.959L8.453 7.687 6.205 13.48H10.7z"/></svg>

src/utils/categoryUtil.ts

@@ -56,6 +56,7 @@ export const getCategoryIcon = (categoryId: string): string => {
  * Each entry can be a single color or [color1, color2] for gradient.
  */
 const PROVIDER_COLORS: Record<string, string | [string, string]> = {
+  anthropic: '#D97757',
   bfl: '#ffffff',
   bria: '#B6B6B6',
   elevenlabs: '#B6B6B6',