The device catalog feed was unusable on paged OPDS clients such as
KOReader: it sliced results into pages but never advertised how to reach
the next page, so clients could only ever fetch the first page (~50 books)
and could not search the catalog.
GetDeviceCatalog:
- Emit the full set of OPDS pagination link relations (self, start, first,
previous, next, last) pointing at catalog?page=N&per_page=M, with the
device auth token appended for path-based auth.
- Emit OpenSearch totalResults/itemsPerPage/startIndex metadata.
- Point rel=search at the OpenSearch description (correct MIME type).
SearchDeviceCatalog now branches on the q parameter:
- No q: return an OpenSearch description document whose Url template
contains the {searchTerms} placeholder, so clients can formulate a query.
- With q: return the existing acquisition results feed, now including
totalResults.
A pure addCatalogPaginationLinks helper holds the page/URL logic so it can
be unit tested without a database. New handler tests cover middle/first/
last/single/empty pages (correct presence of next/previous) and token
appending.
Ordering is intentionally left unchanged (created_at DESC, grouped by
library).
