- library.New now creates BOOKS_DIR (MkdirAll) on startup so uploads don't fail when the directory is missing on a fresh bind mount - uploadSubmit logs the underlying OS error on save/write failures - README: document docker-compose deployment, container UID/GID (100/101) for bind-mounted ./data permissions, and running the admin CLI via docker compose exec Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>