fix(events): neutralize MaintenanceModeMiddleware in test factory

tests/SimpleModule.Tests.Shared/Fixtures/SimpleModuleWebApplicationFactory.cs

@@ -6,6 +6,7 @@
 using Microsoft.Extensions.DependencyInjection;
 using SimpleModule.AuditLogs;
 using SimpleModule.BackgroundJobs;
+using SimpleModule.Core.Maintenance;
 using SimpleModule.Database;
 using SimpleModule.Email;
 using SimpleModule.FeatureFlags;
@@ -92,6 +93,19 @@ protected override void ConfigureWebHost(IWebHostBuilder builder)
                 services
             );
 
+            // Replace the file-based maintenance state provider with a no-op so that
+            // a leftover .maintenance sentinel on the developer's machine (or a CI
+            // agent that ran `sm down`) cannot block API requests and cause spurious
+            // test failures with 503 responses.
+            var maintenanceDescriptor = services.SingleOrDefault(d =>
+                d.ServiceType == typeof(IMaintenanceStateProvider)
+            );
+            if (maintenanceDescriptor is not null)
+            {
+                services.Remove(maintenanceDescriptor);
+            }
+            services.AddSingleton<IMaintenanceStateProvider, NullMaintenanceStateProvider>();
+
             // Add test authentication scheme that bypasses OpenIddict validation
             services.AddTestAuthentication();
 
@@ -182,4 +196,14 @@ private static void TryDeleteWolverineDb()
         }
 #pragma warning restore CA1031
     }
+
+    /// <summary>
+    /// Always reports the application as live. Prevents a stale <c>.maintenance</c>
+    /// sentinel on the developer's machine from returning 503 for every test request.
+    /// </summary>
+    private sealed class NullMaintenanceStateProvider : IMaintenanceStateProvider
+    {
+        public ValueTask<MaintenanceState?> GetAsync(CancellationToken cancellationToken = default) =>
+            ValueTask.FromResult<MaintenanceState?>(null);
+    }
 }