docs(backlog): mark WP-50 done

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/project/backlog/README.md

@@ -100,7 +100,7 @@ for its existing violations, so every WP ends green.
 | [WP-47](WP-47-feature-flags.md)                        | Runtime feature flags (catalog-in-code, admin toggle, FE+backend)                  | 8 · platform/DX/showcase    | done   |
 | [WP-48](WP-48-stamdata-deletion-protection.md)         | Stamdata deletion protection (CI referential gate + editor expire/warn)            | 8 · platform/DX/showcase    | done   |
 | [WP-49](WP-49-openzaak-zaken-read-seam.md)             | OpenZaak zaken read seam (IZaakSource + ZGW client, config-gated, offline default) | 9 · OpenZaak/ZGW            | done   |
-| [WP-50](WP-50-openzaak-create-zaak.md)                 | OpenZaak create-zaak (first write slice)                                           | 9 · OpenZaak/ZGW            | todo   |
+| [WP-50](WP-50-openzaak-create-zaak.md)                 | OpenZaak create-zaak (first write slice)                                           | 9 · OpenZaak/ZGW            | done   |
 | [WP-51](WP-51-openzaak-documenten.md)                  | OpenZaak Documenten (DRC) upload + zaak link                                       | 9 · OpenZaak/ZGW            | todo   |
 | [WP-52](WP-52-openzaak-notificaties.md)                | OpenZaak Notificaties (NRC) live status via webhook                                | 9 · OpenZaak/ZGW            | todo   |
 | [WP-53](WP-53-inbound-identity-and-citizen-scoping.md) | Inbound identity seam + citizen-scoping (per-request BSN, ZGW audit claims)        | 9 · OpenZaak/ZGW            | todo   |

docs/project/backlog/WP-50-openzaak-create-zaak.md

@@ -1,6 +1,6 @@
 # WP-50 — OpenZaak create-zaak (first write slice)
 
-Status: todo
+Status: done (de3bff0)
 Phase: 9 — OpenZaak / ZGW integration
 
 ## Why