Restructure solution layout by module

src/Notify/StellaOps.Notify.Worker/Handlers/INotifyEventHandler.cs

@@ -0,0 +1,10 @@
+using System.Threading;
+using System.Threading.Tasks;
+using StellaOps.Notify.Queue;
+
+namespace StellaOps.Notify.Worker.Handlers;
+
+public interface INotifyEventHandler
+{
+    Task HandleAsync(NotifyQueueEventMessage message, CancellationToken cancellationToken);
+}

src/Notify/StellaOps.Notify.Worker/Handlers/NoOpNotifyEventHandler.cs

@@ -0,0 +1,25 @@
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using StellaOps.Notify.Queue;
+
+namespace StellaOps.Notify.Worker.Handlers;
+
+internal sealed class NoOpNotifyEventHandler : INotifyEventHandler
+{
+    private readonly ILogger<NoOpNotifyEventHandler> _logger;
+
+    public NoOpNotifyEventHandler(ILogger<NoOpNotifyEventHandler> logger)
+    {
+        _logger = logger;
+    }
+
+    public Task HandleAsync(NotifyQueueEventMessage message, CancellationToken cancellationToken)
+    {
+        _logger.LogDebug(
+            "No-op handler acknowledged event {EventId} (tenant {TenantId}).",
+            message.Event.EventId,
+            message.TenantId);
+        return Task.CompletedTask;
+    }
+}