test(acl,verify): cancellation reaches Geannuleerd live (refs #106)

Adds an ACL↔OpenZaak integration test asserting SetZaakToCancellationStatusAsync
records the Geannuleerd status + a resultaat against real OpenZaak, and extends
the domain verify script to confirm a timed-out registration's zaak is cancelled
to Geannuleerd end-to-end.

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

services/acl/Acl.IntegrationTests/OpenZaakFixture.cs

@@ -114,6 +114,19 @@ public sealed class OpenZaakFixture : IDisposable
         return fallback ?? throw new InvalidOperationException($"No statustypen for zaaktype {zaaktypeUrl}");
     }
 
+    /// <summary>Resolve a statustype by its omschrijving (e.g. the S-10c "Geannuleerd" cancellation status).</summary>
+    public async Task<Uri> FindStatustypeByOmschrijvingAsync(Uri zaaktypeUrl, string omschrijving, CancellationToken ct = default)
+    {
+        var query = new Uri(BaseUrl,
+            "/catalogi/api/v1/statustypen?status=alles&zaaktype=" + Uri.EscapeDataString(zaaktypeUrl.ToString()));
+        var page = await GetJsonAsync(query, ct);
+        foreach (var st in page.GetProperty("results").EnumerateArray())
+            if (st.TryGetProperty("omschrijving", out var o) && o.GetString() == omschrijving)
+                return new Uri(st.GetProperty("url").GetString()!);
+
+        throw new InvalidOperationException($"No '{omschrijving}' statustype for zaaktype {zaaktypeUrl}");
+    }
+
     // A ZGW (vng-api-common) HS256 JWT, mirroring the seed's client. Minted here
     // rather than reusing Acl.Infrastructure's internal minter to keep that internal.
     private string MintToken()

services/acl/Acl.IntegrationTests/OpenZaakGatewayIntegrationTests.cs

@@ -75,6 +75,39 @@ public sealed class OpenZaakGatewayIntegrationTests(OpenZaakFixture stack)
         Assert.Equal(eindstatustype.ToString(), status.GetProperty("statustype").GetString());
     }
 
+    [Fact]
+    public async Task Cancelling_a_zaak_records_the_geannuleerd_status_and_a_resultaat()
+    {
+        var zaaktype = await stack.FindPublishedBigZaaktypeAsync();
+        Assert.True(zaaktype is not null,
+            "No published BIG-REGISTRATIE zaaktype found in OpenZaak — bring the stack up and " +
+            "seed it with OZ_PUBLISH=1 (`make integration` does this).");
+
+        var gateway = new OpenZaakGateway(stack.Http, stack.Options);
+        var zaakUrl = await gateway.OpenZaakAsync(new ZaakRequest(
+            Bronorganisatie: "517439943",
+            VerantwoordelijkeOrganisatie: "517439943",
+            Vertrouwelijkheidaanduiding: "openbaar",
+            Zaaktype: zaaktype!,
+            Startdatum: DateOnly.FromDateTime(DateTime.UtcNow),
+            Identificatie: Guid.NewGuid().ToString()));
+
+        await gateway.SetZaakToCancellationStatusAsync(zaakUrl, zaaktype!, DateOnly.FromDateTime(DateTime.UtcNow));
+
+        // The zaak's current status is the Geannuleerd statustype — distinct from the approval eindstatus.
+        var zaak = await stack.GetZaakAsync(zaakUrl);
+        var statusUrl = zaak.GetProperty("status").GetString();
+        Assert.False(string.IsNullOrEmpty(statusUrl), "the cancelled zaak has no current status");
+
+        var status = await stack.GetJsonAsync(new Uri(statusUrl!));
+        var geannuleerd = await stack.FindStatustypeByOmschrijvingAsync(zaaktype!, "Geannuleerd");
+        Assert.Equal(geannuleerd.ToString(), status.GetProperty("statustype").GetString());
+
+        // ...and a resultaat is recorded (OpenZaak requires it before a closing/terminal status).
+        Assert.False(string.IsNullOrEmpty(zaak.GetProperty("resultaat").GetString()),
+            "the cancelled zaak has no resultaat");
+    }
+
     [Fact]
     public async Task Storing_a_diploma_creates_a_real_informatieobject_related_to_the_zaak()
     {