The embed section passed code through SafeHtmlContent which ran DOMPurify
with FORBID_TAGS including 'iframe', silently removing the element.
Replaced SafeHtmlContent with a new sanitizeEmbedHtml() that uses a
whitelist of ALLOWED_TAGS: ['iframe'] and restricts src to https: only,
so Google Forms, YouTube, and other https embeds render while javascript:
sources and non-iframe tags are still blocked.
Rotimi Best
8d2f2a6d2d