Reads metadata.db and copies the books into a library — from a zip uploaded on
the library settings page, or from a path with `litestar calibre-import`. The
source is never touched, and re-running only picks up what is new.
Also names the formats mimetypes does not know: a Calibre library is full of
MOBI and AZW3, and a null content type used to fail the book endpoint.
Match on a shared identifier, or on a normalised title credited to a shared
author, and report candidates rather than refusing anything — a metadata match
is a guess, and a second edition is not a mistake. Adds a library-wide review
pass, dismissals, and renames the fingerprint pre-flight to duplicate-files.
The hash lives in the database and the file does not, so a file deleted behind
the app's back went on refusing its own replacement. Matches are now checked
against disk, and re-adding a book's own missing file writes it back into the
row that already describes it.
Incoming files are matched against what is already stored, keyed on the
KOReader hash and the file size. Bulk uploads skip and report them, deliberate
creates are refused with a 409, the consume directory parks them aside, and
allow_duplicates overrides all three.
Also: books whose metadata generates a path another book already owns are moved
aside, so a forced copy cannot overwrite the original's files.