Add a "Not on device" Browse tile listing recently added books not yet
downloaded here. On-device state is local to KOReader and has no
server-side filter, so the list is assembled by a bounded walk of the
newest books, capped by both a page budget and the server's ids limit.
It takes the slot of the Search tile, which duplicated the title bar
search button present on every non-detail page.
Add a folder picker to the bulk download settings, sharing one chooser
with the single-book dialog so both write the same download_dir.
Badge every Browse tile the server can count. Authors and series reuse
the cached totals the web sidebar already requests; libraries,
collections, smart scopes and in-progress get dedicated count queries
rather than the list methods behind the section endpoints, which
aggregate per-entity book counts a badge never reads. Badges are
right-aligned and abbreviated past 999 so the column stays fixed.
Replace the shared count path that paged and hydrated a book to read a
single integer, removing five queries per count on the dashboard, the
series read-through summary and the section endpoints.
Closes#869
neon