feat(infra): Flowable RegistratieVerlopen worker + document-wait completion (refs #102)

FlowableWorkflowClient implements IRegistratieVerlopenClient (acquire/complete the
RegistratieVerlopen jobs) and CompleteDocumentWaitAsync (complete WachtOpDocumenten,
best-effort). Wires the RegistratieVerlopenProcessor + hosted RegistratieVerlopenPump
into the domain host and excludes the pump from mutation (like the other pumps).
Fakes updated for the new IWorkflowClient member.

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

services/domain/Big.Application/Ports.cs

@@ -25,6 +25,14 @@ public interface IWorkflowClient
     /// ended, or not yet parked) it is a no-op; the aggregate is INGETROKKEN regardless.
     /// </summary>
     Task WithdrawProcessAsync(string processInstanceId, CancellationToken ct = default);
+
+    /// <summary>
+    /// Signal that the required documents have arrived (S-10a): complete the <c>WachtOpDocumenten</c>
+    /// user task in the instance so the process leaves the 30-day wait state and continues to
+    /// beoordeling (ADR-0017). Best-effort — if the instance is not parked at that task (already
+    /// continued, or timed out) it is a no-op. The upload trigger that calls this is wired in S-10b.
+    /// </summary>
+    Task CompleteDocumentWaitAsync(string processInstanceId, CancellationToken ct = default);
 }
 
 /// <summary>