Replaces the `<iframe src={presignedUrl}>` preview path which
delegated rendering to the browser's built-in PDF viewer. The iframe
worked on desktop but failed on mobile (older Android Chrome
refuses inline PDFs; iOS Safari opens a new tab).
`<PdfViewer>` renders via pdfjs-dist + react-pdf so the experience
is identical across all browsers + form factors. Adds page nav,
zoom controls, and per-page accessibility labels.
Lazy-loaded via next/dynamic with ssr:false — pdfjs is ~150kb gzip,
no route ships it unless a PDF is actually previewed.
pdfjs worker + CMaps + fonts loaded from unpkg CDN pinned to the
matched pdfjs-dist version (first-load cost paid once per user, no
bundle-size impact on routes that never preview a PDF).
Verified: tsc clean, vitest 1315/1315, next build green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Matt
d0a3a054b6