test(acceptance): beoordeling escalation — both branches (S-14, refs #15)

Gherkin scenarios for the two branches: a beoordeling left unclaimed for 14 days
escalates to the teamlead, and one completed before the timer fires does not.
Driven through the escalation worker against an in-memory Flowable stand-in.

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

tests/acceptance/Support/InMemoryDomainPorts.cs

@@ -1,5 +1,6 @@
 using Big.Application;
 using Big.Domain;
+using Big.Infrastructure;
 
 namespace Acceptance.Support;
 
@@ -73,6 +74,59 @@ public sealed class InMemoryUserTaskClient : IUserTaskClient
     }
 }
 
+/// <summary>An in-memory Flowable stand-in for the beoordeling-escalation scenario (S-14): it models
+/// one Beoordelen task per process instance — its candidate group and whether it is still open — and
+/// the escalation jobs the non-interrupting 14-day boundary timer parks. It drives the escalation
+/// worker's behaviour without a running Flowable; the timer firing live is the verify-domain check.</summary>
+public sealed class InMemoryEscalatieClient : IBeoordelingEscalatieClient
+{
+    private sealed class ParkedTask
+    {
+        public string CandidateGroup { get; set; } = "behandelaar";
+        public bool IsOpen { get; set; } = true;
+    }
+
+    private readonly Dictionary<string, ParkedTask> _tasks = [];
+    private readonly List<EscalatieJob> _parked = [];
+    private int _seq;
+
+    /// <summary>A registration parks at Beoordelen, claimable by the behandelaar group.</summary>
+    public string ParkBeoordeling()
+    {
+        var pid = $"pi-{++_seq}";
+        _tasks[pid] = new ParkedTask();
+        return pid;
+    }
+
+    /// <summary>The behandelaar completes the beoordeling before the timer fires: the task closes.</summary>
+    public void CompleteBeoordeling(string processInstanceId) => _tasks[processInstanceId].IsOpen = false;
+
+    /// <summary>The 14-day boundary timer fires: a non-interrupting token parks an escalation job.</summary>
+    public void FireEscalationTimer(string processInstanceId)
+        => _parked.Add(new EscalatieJob($"job-{++_seq}", processInstanceId));
+
+    /// <summary>The candidate group that may currently pick the task up.</summary>
+    public string CandidateGroupFor(string processInstanceId) => _tasks[processInstanceId].CandidateGroup;
+
+    public Task<IReadOnlyList<EscalatieJob>> AcquireBeoordelingEscalatieJobsAsync(int maxJobs, CancellationToken ct = default)
+        => Task.FromResult<IReadOnlyList<EscalatieJob>>(_parked.Take(maxJobs).ToList());
+
+    public Task ReassignBeoordelingToTeamleadAsync(string processInstanceId, CancellationToken ct = default)
+    {
+        // No-op if the behandelaar already completed it — the timer/completion race (§8.6).
+        var task = _tasks[processInstanceId];
+        if (task.IsOpen)
+            task.CandidateGroup = "teamlead";
+        return Task.CompletedTask;
+    }
+
+    public Task CompleteBeoordelingEscalatieJobAsync(string jobId, CancellationToken ct = default)
+    {
+        _parked.RemoveAll(j => j.JobId == jobId);
+        return Task.CompletedTask;
+    }
+}
+
 /// <summary>An in-memory registration store for the domain acceptance scenario.</summary>
 public sealed class InMemoryRegistrationStore : IRegistrationStore
 {