feature/add german national lib

[codebude]

• Add Deutsche Nationalbibliothek as book import source
• Add Deutsche Nationalbibliothek to import search frontend
• Document Deutsche Nationalbibliothek import source

[github-actions]

🧪 Test Results — bc04722

✅ Backend (pytest) — 1175 passed, 0 failed, 0 skipped (1175 total)
✅ CLI (pytest) — 54 passed, 0 failed, 0 skipped (54 total)
✅ Frontend (vitest) — 543 passed, 0 failed, 0 skipped (543 total)
✅ E2E (Playwright) — 79 passed, 0 failed, 0 skipped (79 total)

Summary: ✅ All 1851 tests passed

[mj0nez]

Nice, works as expected! Only covers are not yet fetched. :)

[codebude]

@mj0nez the dnb SRU api does not provide cover images. I believe they intentionally do not provide images, because:

The basis for displaying cover images in the DNB catalogue is an agreement between the German Library Association (dbv) and the collecting society VG Bild-Kunst. The agreement allows libraries to use the cover service of the VLB (German Books in Print).

Source: https://www.dnb.de/EN/Professionell/Metadatendienste/Kataloganreicherung/Cover/cover.html?nn=1936038#doc1936034bodyText1

Therefore I would skip covers from dnb here and point to the both cover search features of LibrisLog:

• https://docs.librislog.app/guide/using-librislog/library.html#covers
• https://docs.librislog.app/guide/using-librislog/missing-covers.html#missing-covers-workflow

[mj0nez]

Fair, thanks for implementing this on such a short notice!