Fix server sanitizer to persist appleBooksUrl/Label on customLinks; v1.1.43

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

server/helpers.js

@@ -180,6 +180,8 @@ function sanitizeCustomLinks(value) {
         description: typeof item.description === 'string' ? item.description.trim().slice(0, 4000) : '',
         amazonUrl: sanitizeUrl(item.amazonUrl),
         amazonLabel: typeof item.amazonLabel === 'string' ? item.amazonLabel.trim().slice(0, 120) : '',
+        appleBooksUrl: sanitizeUrl(item.appleBooksUrl),
+        appleBooksLabel: typeof item.appleBooksLabel === 'string' ? item.appleBooksLabel.trim().slice(0, 120) : '',
         tags: Array.isArray(item.tags)
           ? item.tags.filter(tag => typeof tag === 'string').map(tag => tag.trim()).filter(Boolean).slice(0, 20)
           : [],