v1.31.0

Added

• Mobile PDF preview: PDFs now render inline in the document viewer on iOS Safari and other mobile browsers that leave <iframe>/<embed> blank, using a self-hosted pdf.js canvas renderer (no CDN). Pages render lazily with a memory cap, the modal body is the single scroller, and a sticky page indicator shows position. Desktop browsers keep their native inline PDF viewer.
• PDF preview accessibility: a screen-reader note explains the graphical preview and points to the always-available "open in new tab" and download actions; load completion is announced, and a single unrenderable page shows an inline error instead of loading forever.

Changed

• PDFs with non-embedded standard fonts (Helvetica/Times/Courier) now render correctly on mobile via self-hosted pdf.js standard font data.