Extends the OpenZaak seam with IDocumentSource, sibling of IZaakSource
(WP-49/50): an upload always lands locally first (DocumentStore stays
the record of truth for preview/download/audit) and, when
Zgw:Enabled=true, is also registered as a DRC enkelvoudiginformatie-
object; once a zaak exists (IZaakSource.CreateZaak now also returns
its ZaakUrl), submit links each document to it via zaakinformatie-
object. FE upload/list DTOs are unchanged.
- ZgwOptions gains DrcBaseUrl + a category->informatieobjecttype URL
map (the document analogue of ZaaktypeUrls).
- LocalDocumentSource is the same DocumentStore.Add/Link calls the
endpoints used to make inline — zero behaviour change offline.
- OpenZaakDocumentSource POSTs the eio then the zaak link, persisting
the DRC url (DocumentStore.SetDrcUrl) so linking doesn't re-upload.
- Factored the GET/POST-with-bearer-JWT plumbing shared with
OpenZaakZaakSource into ZgwHttpClient; shared the stub handler
between the two source test classes as ZgwStubHandler.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
