A book is a folder of chapters, not a file. The scanner gained a grouping
mode so a directory of tracks becomes one item with ordered files.
- registry: MediaType.Group (file | directory). Audiobooks and music group by
directory; everything else stays one item per file.
- scanner: builds groups, upserts one item per group, marks items missing when
their directory disappears, and keeps the file-level added/updated/missing
accounting. Tracks are ordered naturally, so chapter 2 precedes chapter 10.
- natsort: one shared natural-order comparator, now used by both the scanner
and the comics module (which had its own copy).
- media: GET /items/{id}/files/{fileID} streams one specific track. It
verifies the file belongs to the item, so an item id cannot be paired with
another item's file id.
No new module was needed for playback: the polymorphic progress table already
keys on file_id, so per-chapter resume fell out of the existing design. The
web player resumes the exact track and offset.
Verified: 3 chapters grouped into one book titled "Mistborn", natural order,
range request returned 206, mismatched file id 404s, per-track progress
round-trips.
- comics: reads pages straight out of the archive on demand. No extraction
pass, so a 200-page CBZ is not materialised for a reader who views three
pages. Pages are read into memory and served via http.ServeContent, which
gives Range for free.
- natural page ordering: page2 sorts before page10. Lexical ordering shuffles
a numbered archive, which is the difference between a readable book and a
scrambled one.
- skips __MACOSX and dotfiles; rejects archives with no images.
- cover is the first page.
- media.Item gained ModTime (from the backing file) so page responses carry a
Last-Modified and support conditional GETs.
- web: ComicReader with a bounded prefetch window (two pages each way), page
jump, keyboard nav, and progress stored as a page number.
Verified: 3-page CBZ served in natural order, out-of-range 404, cover from
page 1, progress round-trip. svelte-check 0/0.
