fix(acceptance): implement the resolve API in the in-memory ZGW gateway (refs #113)

The acceptance InMemoryZaakGateway now implements IZaakGateway's new
Resolve{Zaaktype,Informatieobjecttype}UrlAsync, and the "een zaak openen" step
configures the ACL by identificatie + points the fake's resolved zaaktype at the
scenario URL — the Release build (which compiles tests/acceptance) failed without
this. All 17 acceptance + 54 ACL unit tests green.

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

tests/acceptance/Support/InMemoryZaakGateway.cs

@@ -14,6 +14,11 @@ public sealed class InMemoryZaakGateway : IZaakGateway
     public (Uri Zaak, Uri Zaaktype, DateOnly Datum)? Approved { get; private set; }
     public (Uri Zaak, Uri Zaaktype, DateOnly Datum)? Cancelled { get; private set; }
 
+    // The URLs the catalogus resolves the configured identificatie/omschrijving to (S-27); settable so
+    // a scenario can pin the zaaktype the ACL should default-fill.
+    public Uri ResolvedZaaktypeUrl { get; set; } = new("http://openzaak/catalogi/api/v1/zaaktypen/big");
+    public Uri ResolvedInformatieobjecttypeUrl { get; set; } = new("http://openzaak/catalogi/api/v1/informatieobjecttypen/dip");
+
     public Task<Uri> OpenZaakAsync(ZaakRequest request, CancellationToken ct = default)
     {
         Captured = request;
@@ -37,4 +42,10 @@ public sealed class InMemoryZaakGateway : IZaakGateway
 
     public Task<Uri> StoreDocumentAsync(DocumentRequest request, CancellationToken ct = default)
         => Task.FromResult(new Uri("http://openzaak/documenten/api/v1/enkelvoudiginformatieobjecten/acc-doc"));
+
+    public Task<Uri> ResolveZaaktypeUrlAsync(string identificatie, CancellationToken ct = default)
+        => Task.FromResult(ResolvedZaaktypeUrl);
+
+    public Task<Uri> ResolveInformatieobjecttypeUrlAsync(string omschrijving, CancellationToken ct = default)
+        => Task.FromResult(ResolvedInformatieobjecttypeUrl);
 }