feat(registratie): WP-36 — admin cases page + admin delete

Admin-only overview of all cases across owners + an admin delete, gated by a new
`cases:manage` capability (Authz role→cap + CanManageCases + CasesAdmin gate;
FE capability + guard + nav + role.interceptor prefix — the org-template/stamdata
recipe). Backend adds ApplicationStore.ListAll()/DeleteAny() and GET /admin/cases +
DELETE /admin/cases/{id}; admin delete removes ANY case incl. submitted. Page lives
in registratie/ui (owns the Aanvraag aggregate; reuses aanvraag-view + parse),
routed /beheer/zaken; delete guarded by a native confirm, optimistic with rollback.
Typed client regenerated (documents the new endpoints + owner field).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/project/backlog/README.md

@@ -80,7 +80,7 @@ for its existing violations, so every WP ends green.
 | [WP-33](WP-33-dev-switchers.md)            | In-app dev switchers (scenario + role)                                            | 7 · refinements             | done   |
 | [WP-34](WP-34-adres-phone-brp-readonly.md) | Adres: phone field + BRP address read-only                                        | 7 · refinements             | done   |
 | [WP-35](WP-35-one-concept-per-type.md)     | One Concept per case type (server-enforced)                                       | 7 · refinements             | done   |
-| [WP-36](WP-36-admin-cases.md)              | Admin cases page + admin delete                                                   | 7 · refinements             | todo   |
+| [WP-36](WP-36-admin-cases.md)              | Admin cases page + admin delete                                                   | 7 · refinements             | done   |
 
 Sequencing dependencies (stated in the WPs too): 01 before 10–15 (axe covers story churn);
 03/04 before 05–09 (boundaries stop new violations during refactors); 06 before 07 (typed