v0.2.12: Subject-namespace filtering, totalCount consistency, and newspaper page metadata fallbacks

Subject-namespace filtering, totalCount consistency, and newspaper page metadata fallbacks

Three fixes: LCSH-only subject suggestions, totalCount agreement on empty results, and URL-derived newspaper page metadata.

Added:

• libofcongress_get_newspaper_page derives date and sequence from the page URL when the resource endpoint omits them (#28)

Fixed:

• libofcongress_search_subjects filters suggest results to the LCSH subjects namespace (#25)
• libofcongress_browse_collections, libofcongress_search, and libofcongress_search_newspapers re-enrich totalCount to 0 on empty results (#27)

171 tests pass; bun run devcheck clean.

CHANGELOG v0.2.12