SingleFile CLI 2.9.1

CLI fixes and improvements

• The fonts declared inside a frame whose content cannot be read are kept when saving with --browser-engine firefox. Firefox reports the styles of a document it never rendered instead of reporting none, so the faces such a frame declares were pruned
• The zoom out applied while deferred images load is anchored at the top of the document and follows the scroll position
• The bundled zip.js is updated to 2.11.1

Co-authored by Claude (Claude Code)