feat(builder): shared asset upload/list util

Extract uploadAsset/listAssets into utils/assets.ts, lifting the exact
uploadToWhp body and list_assets fetch pattern already duplicated across
shared.tsx/ImageBlock/Logo/Navbar/etc. shared.tsx's uploadToWhp is now a
thin re-export (`export const uploadToWhp = uploadAsset`) so its ~6
existing callers are unaffected.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

craft/src/panels/right/styles/shared.tsx

@@ -3,6 +3,7 @@ import { useEditor } from '@craftjs/core';
 import {
   GRADIENTS,
 } from '../../../constants/presets';
+import { uploadAsset } from '../../../utils/assets';
 
 /* ---------- Helper: auto text color for bg ---------- */
 export function autoTextColor(bg: string): string {
@@ -17,23 +18,11 @@ export function autoTextColor(bg: string): string {
   return '#ffffff';
 }
 
-/* ---------- Helper: upload to WHP ---------- */
-export async function uploadToWhp(file: File): Promise<string | null> {
-  const cfg = (window as any).WHP_CONFIG;
-  if (!cfg) return URL.createObjectURL(file);
-  const formData = new FormData();
-  formData.append('file', file);
-  try {
-    const resp = await fetch(`${cfg.apiUrl}?action=upload_asset&site_id=${cfg.siteId}`, {
-      method: 'POST',
-      headers: { 'X-CSRF-Token': cfg.csrfToken },
-      body: formData,
-    });
-    const data = await resp.json();
-    if (data.success && data.url) return data.url;
-    return null;
-  } catch { return null; }
-}
+/* ---------- Helper: upload to WHP ----------
+   Thin re-export over the shared `uploadAsset` util (`@/utils/assets`) so
+   the existing callers importing `uploadToWhp` from here keep working
+   unchanged. */
+export const uploadToWhp = uploadAsset;
 
 /* ---------- Shared inline styles ---------- */
 export const labelStyle: CSSProperties = { fontSize: 11, color: '#a1a1aa', display: 'block', marginBottom: 4, textTransform: 'capitalize' };

craft/src/panels/right/styles/shared.uploadToWhp.test.ts

@@ -0,0 +1,21 @@
+import { describe, test, expect, vi, afterEach } from 'vitest';
+import { uploadToWhp } from './shared';
+import { uploadAsset } from '../../../utils/assets';
+
+describe('shared.uploadToWhp', () => {
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    delete (window as any).WHP_CONFIG;
+  });
+
+  test('is a thin re-export of uploadAsset (same function reference)', () => {
+    expect(uploadToWhp).toBe(uploadAsset);
+  });
+
+  test('still works standalone (no WHP_CONFIG -> blob: URL) for existing callers', async () => {
+    (URL as any).createObjectURL = vi.fn(() => 'blob:mock-url');
+    const file = new File(['x'], 'photo.png', { type: 'image/png' });
+    const url = await uploadToWhp(file);
+    expect(url).toBe('blob:mock-url');
+  });
+});