Why: The conversation and office fallbacks wrote marked output straight into the page, including converted docx HTML.
Evidence: html-sinks ratchet forbids new innerHTML writes outside @ui safeHtml.
Impact: Conversation keeps line-break rendering. Unsafe links are stripped after docx and pptx preview. dompurify is deduped with the UI package.
Refs: feature/sillytavern-review
Co-authored-by: Cursor <cursoragent@cursor.com>