test(acl): cancellation gateway posts Geannuleerd + Vervallen; approval picks resultaat by name (refs #106)

S-10c: the document-timeout branch must set the zaak to a distinct
cancellation statustype (Geannuleerd) + resultaat (Vervallen), resolved by
omschrijving. With a second resultaattype present, approval must also
resolve its resultaat (Geregistreerd) by name rather than taking the first.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/acceptance/Support/InMemoryZaakGateway.cs

@@ -12,6 +12,7 @@ public sealed class InMemoryZaakGateway : IZaakGateway
 
     public ZaakRequest? Captured { get; private set; }
     public (Uri Zaak, Uri Zaaktype, DateOnly Datum)? Approved { get; private set; }
+    public (Uri Zaak, Uri Zaaktype, DateOnly Datum)? Cancelled { get; private set; }
 
     public Task<Uri> OpenZaakAsync(ZaakRequest request, CancellationToken ct = default)
     {
@@ -25,6 +26,12 @@ public sealed class InMemoryZaakGateway : IZaakGateway
         return Task.CompletedTask;
     }
 
+    public Task SetZaakToCancellationStatusAsync(Uri zaakUrl, Uri zaaktypeUrl, DateOnly datumStatusGezet, CancellationToken ct = default)
+    {
+        Cancelled = (zaakUrl, zaaktypeUrl, datumStatusGezet);
+        return Task.CompletedTask;
+    }
+
     public Task<string> GetZaakIdentificatieAsync(Uri zaakUrl, CancellationToken ct = default)
         => Task.FromResult("ACC-REF-1");