fix(web): images, video, HTML and PDF preview in a thread before its first message (#17352)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
e0c80c198cJulius Marminge committed on 10/8/2026, 11:40:02 PM· committed by GitHubparent3bfbc37
3 files changedLine totals unavailable