feat(phase-4): application layer + background workers — 202/202 tests green

Use cases (Marathon.Application/UseCases/):
- PullUpcomingEventsUseCase: scrape + persist new events + capture pre-match snapshots
- PullLiveOddsUseCase: refresh live snapshots for all stored events
- PullResultsUseCase: Phase 4 scaffold; delegates to ScrapeResultsAsync (Phase 3 no-op);
  Phase 8 will replace with watch-list polling
- ExportToExcelUseCase: resolves export dir from StorageOptions, delegates to IExcelExporter

ApplicationModule.AddMarathonApplication(IServiceCollection) — no IConfiguration needed.

Background workers (Marathon.Infrastructure/Workers/):
- UpcomingEventsPoller: Cronos 6-field cron schedule (default every 6 h)
- LiveOddsPoller: fixed interval (WorkerOptions.LivePollIntervalSeconds, default 30 s)
- ResultsWatchListPoller: scaffold, disabled by default (WorkerOptions.ResultsPollerEnabled=false)
All three: exception-swallowing, cancellation-aware, scoped DI via CreateAsyncScope().

InfrastructureModule.AddMarathonInfrastructure(IServiceCollection, IConfiguration):
- Composes AddMarathonPersistence + AddMarathonScraping + WorkerOptions + 3 hosted services

App.xaml.cs: replace reflection-based TryAddApplicationAndInfrastructure with direct
AddMarathonApplication() + AddMarathonInfrastructure(config) calls.

Resolved Phase 3 TODO: bind Sports:Basketball:QuarterMode from config in ScrapingModule.

appsettings.json: add Workers.LivePollIntervalSeconds, ResultsPollIntervalSeconds,
ResultsPollerEnabled; add Sports.Basketball.QuarterMode.

Settings.razor + WorkerOptions (UI) + SharedResource.*.resx: surface new Workers fields.

Tests: +14 Application use-case tests, +3 Infrastructure worker tests (185 → 202 total).

src/Marathon.Hosts.WpfBlazor/App.xaml.cs

@@ -1,6 +1,8 @@
 using System.Globalization;
 using System.IO;
 using System.Windows;
+using Marathon.Application;
+using Marathon.Infrastructure;
 using Marathon.UI.Services;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
@@ -73,9 +75,9 @@ public partial class App : System.Windows.Application
         builder.Services.AddBlazorWebViewDeveloperTools();
 #endif
 
-        // Compose Application + Infrastructure modules if they exist. Parallel
-        // Phase 2/3/4 work may still be merging these; we degrade gracefully.
-        TryAddApplicationAndInfrastructure(builder.Services, builder.Configuration);
+        // Application use cases + Infrastructure (persistence, scraping, workers).
+        builder.Services.AddMarathonApplication();
+        builder.Services.AddMarathonInfrastructure(builder.Configuration);
 
         // MainWindow needs the IServiceProvider for BlazorWebView.Services binding.
         builder.Services.AddSingleton<MainWindow>();
@@ -104,50 +106,6 @@ public partial class App : System.Windows.Application
             ? level
             : Serilog.Events.LogEventLevel.Information;
 
-    /// <summary>
-    /// Best-effort wiring of the Application + Infrastructure DI modules.
-    /// TODO(phase-4): the orchestrator will land a single
-    /// <c>AddMarathonInfrastructure(config)</c> entry point. Until then we use
-    /// reflection to call whichever extension methods exist so partial merges
-    /// don't break compilation of this host.
-    /// </summary>
-    private static void TryAddApplicationAndInfrastructure(IServiceCollection services, IConfiguration configuration)
-    {
-        TryInvokeExtension(services, configuration, "Marathon.Application.DependencyInjection", "AddMarathonApplication");
-        TryInvokeExtension(services, configuration, "Marathon.Infrastructure.DependencyInjection", "AddMarathonInfrastructure");
-        TryInvokeExtension(services, configuration, "Marathon.Infrastructure.Persistence.PersistenceServiceCollectionExtensions", "AddMarathonPersistence");
-        TryInvokeExtension(services, configuration, "Marathon.Infrastructure.Scraping.ScrapingServiceCollectionExtensions", "AddMarathonScraping");
-    }
-
-    private static void TryInvokeExtension(IServiceCollection services, IConfiguration configuration, string typeName, string methodName)
-    {
-        try
-        {
-            // Probe across all loaded assemblies — project refs cause them to load on startup.
-            foreach (var asm in AppDomain.CurrentDomain.GetAssemblies())
-            {
-                var type = asm.GetType(typeName, throwOnError: false, ignoreCase: false);
-                if (type is null)
-                {
-                    continue;
-                }
-
-                var method = type.GetMethod(methodName, new[] { typeof(IServiceCollection), typeof(IConfiguration) });
-                if (method is null)
-                {
-                    continue;
-                }
-
-                method.Invoke(null, new object[] { services, configuration });
-                return;
-            }
-        }
-        catch (Exception ex)
-        {
-            Log.Warning(ex, "Optional module {Type}.{Method} not wired", typeName, methodName);
-        }
-    }
-
     protected override void OnExit(ExitEventArgs e)
     {
         try

src/Marathon.Hosts.WpfBlazor/appsettings.json

@@ -19,9 +19,17 @@
     "RequestTimeoutSeconds": 30
   },
   "Workers": {
-    "UpcomingScheduleCron": "0 */5 * * * *",
+    "UpcomingScheduleCron": "0 0 */6 * * *",
     "LivePollerEnabled": true,
-    "UpcomingPollerEnabled": true
+    "UpcomingPollerEnabled": true,
+    "LivePollIntervalSeconds": 30,
+    "ResultsPollIntervalSeconds": 300,
+    "ResultsPollerEnabled": false
+  },
+  "Sports": {
+    "Basketball": {
+      "QuarterMode": false
+    }
   },
   "Storage": {
     "DatabasePath": "./data/marathon.db",