feature: In-App Simulation Runner (Backend)

VigilCare.Simulation.Core/Engine/IApiPoller.cs

@@ -0,0 +1,10 @@
+namespace VigilCare.Simulation;
+
+/// <summary>
+/// Optional post-cluster polling hook. Console hosts display scores/alerts;
+/// the API host passes null — polling is a display concern.
+/// </summary>
+public interface IApiPoller
+{
+    Task PollAndDisplayAsync(Guid encounterId, string simTime);
+}