Routing: footer "Explorer"/"Validators" pointed to non-existent /network (4 spots
in AppLayout + LandingPageDesktop) and Explorer/Forum quick-links pointed to bare
/governance (no route) -> all hit the 404 catch-all. Repointed to /explorer and
/governance/assembly; footer "Vote" /-> /elections.
Security (stored XSS): DiscussionThread.parseMarkdown did regex->HTML then
dangerouslySetInnerHTML with no escaping/sanitizer, so <img onerror>/javascript:
links in user comments executed. Now escape HTML first, then DOMPurify-sanitize the
output to a safe tag/attr allow-list with http(s)-only hrefs.