nginx:alpine mime.types only covers .js, not .mjs. The pdfjs-dist v4
worker is output as pdf.worker-*.mjs; without the correct MIME type the
browser refuses to execute it as a module worker and pdfjs throws
'Network Error', blocking the PDF backdrop from rendering.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Vite hashes all JS/CSS assets, so those can be cached for 30 days.
But index.html must never be cached — it references the current hashes.
Caching index.html meant users ran old JS after deploys.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
