A folder that Bindery made hid a missing volume mount. The books went
to a folder inside the container, and CWA never saw them. A missing
folder is now an error in the log at the start, and each upload fails
with a message that names the mount.
Bindery mounts no CWA database. It searches the OPDS feed by title and
reads the story URL inside each candidate epub to find the library book.
Updates go to the ingest folder with a .cwa.json sidecar, so CWA replaces
the epub of the existing book.