Surface NER routing provenance (ModelOrigin, NerModelsInvoked) through the pipeline and WPF harness so English/Tamil routing is observable during POC validation. Consolidate docs into solution-guide and add NER logs, topic filtering, and batch UI fixes in the test harness.

src/PiiRedaction.TestHarness.Wpf/App.xaml.cs

@@ -3,7 +3,9 @@ using System.Windows;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
 using PiiRedaction.TestHarness.Wpf.DependencyInjection;
+using PiiRedaction.TestHarness.Wpf.Logging;
 using PiiRedaction.TestHarness.Wpf.Services;
 using PiiRedaction.TestHarness.Wpf.ViewModels;
 
@@ -24,6 +26,11 @@ public partial class App : Application
                 configuration.AddJsonFile("appsettings.json", optional: false, reloadOnChange: true);
                 configuration.AddEnvironmentVariables();
             })
+            .ConfigureLogging((context, logging) =>
+            {
+                logging.AddConfiguration(context.Configuration.GetSection("Logging"));
+                logging.AddFilter("PiiRedaction.Infrastructure.Onnx", LogLevel.Debug);
+            })
             .ConfigureServices((context, services) =>
             {
                 services.AddPiiRedactionServices(context.Configuration);
@@ -38,6 +45,9 @@ public partial class App : Application
 
         Directory.SetCurrentDirectory(AppContext.BaseDirectory);
 
+        var loggerFactory = _host.Services.GetRequiredService<ILoggerFactory>();
+        loggerFactory.AddProvider(new UiLoggerProvider(_host.Services.GetRequiredService<INerLogService>()));
+
         await _host.StartAsync().ConfigureAwait(true);
 
         var mainWindow = _host.Services.GetRequiredService<MainWindow>();