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>

backend/src/BigRegister.Api/Contracts/Dtos.cs

@@ -96,7 +96,8 @@ public sealed record AanvraagStatusDto(
 public sealed record ApplicationSummaryDto(
     string Id, string Type, AanvraagStatusDto Status,
     IReadOnlyList<string> DocumentIds,
-    string CreatedAt, string UpdatedAt, string? SubmittedAt);
+    string CreatedAt, string UpdatedAt, string? SubmittedAt,
+    string? Owner = null);   // populated for the admin cross-owner list (WP-36); the user's own list ignores it
 
 public sealed record ApplicationDetailDto(
     string Id, string Type, AanvraagStatusDto Status,