Page and cover blobs are content-addressed by unguessable, immutable keys, but /files sent no Cache-Control, so the browser refetched on every reader open — defeating the whole-chapter and next-chapter preloading (and re- proxying every byte through the node server in prod). Send `Cache-Control: public, max-age=31536000, immutable`. Bump to 0.124.3. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>