Add Tamil NER routing and WPF test harness for POC validation.

Introduce dual-script ONNX NER routing (English/Tamil/mixed), Tamil console samples and integration tests, model download scripts, and a resizable WPF MVVM harness with click-to-load prompts, batch validation, and runtime-adjustable detection panels.

tests/TestSupport.Shared/RealNerModelFixture.cs

@@ -6,12 +6,12 @@ using PiiRedaction.Infrastructure.Onnx;
 namespace PiiRedaction.Tests.Shared;
 
 /// <summary>
-/// Reuses a single <see cref="OnnxNerModelRunner"/> per fixture for performance.
+/// Reuses a single <see cref="EnglishOnnxNerRunner"/> per fixture for performance.
 /// Skips all tests in the class when the ONNX model is missing or cannot be loaded.
 /// </summary>
 public abstract class RealNerModelFixture
 {
-    protected OnnxNerModelRunner Runner { get; private set; } = null!;
+    protected EnglishOnnxNerRunner Runner { get; private set; } = null!;
 
     protected string ModelPath { get; private set; } = null!;
 
@@ -24,8 +24,12 @@ public abstract class RealNerModelFixture
             Assert.Ignore(RealNerModelPaths.ModelMissingMessage);
         }
 
-        var options = Options.Create(new PiiRedactionOptions { OnnxModelPath = ModelPath });
-        Runner = new OnnxNerModelRunner(options, NullLogger<OnnxNerModelRunner>.Instance);
+        var options = Options.Create(new PiiRedactionOptions
+        {
+            EnglishOnnxModelPath = ModelPath,
+            OnnxModelPath = ModelPath
+        });
+        Runner = new EnglishOnnxNerRunner(options, NullLogger<EnglishOnnxNerRunner>.Instance);
 
         if (!Runner.IsModelAvailable)
         {

tests/TestSupport.Shared/RealNerModelPaths.cs

@@ -7,16 +7,23 @@ public static class RealNerModelPaths
 
     public static string ResolveRepoModelPath()
     {
-        var directory = new DirectoryInfo(AppContext.BaseDirectory);
-        while (directory is not null)
+        foreach (var relativePath in new[]
+                 {
+                     Path.Combine("models", "en", "ner-model.onnx"),
+                     Path.Combine("models", "ner-model.onnx")
+                 })
         {
-            var candidate = Path.Combine(directory.FullName, "models", "ner-model.onnx");
-            if (File.Exists(candidate))
+            var directory = new DirectoryInfo(AppContext.BaseDirectory);
+            while (directory is not null)
             {
-                return candidate;
-            }
+                var candidate = Path.Combine(directory.FullName, relativePath);
+                if (File.Exists(candidate))
+                {
+                    return candidate;
+                }
 
-            directory = directory.Parent;
+                directory = directory.Parent;
+            }
         }
 
         return Path.Combine(Environment.CurrentDirectory, "models", "ner-model.onnx");

tests/TestSupport.Shared/RealRoutingNerModelFixture.cs

@@ -0,0 +1,69 @@
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+using PiiRedaction.Core.Configuration;
+using PiiRedaction.Infrastructure.Onnx;
+
+namespace PiiRedaction.Tests.Shared;
+
+/// <summary>
+/// Loads English and Tamil ONNX runners and exposes a <see cref="RoutingOnnxNerModelRunner"/>.
+/// Skips when either model is missing or cannot be loaded.
+/// </summary>
+public abstract class RealRoutingNerModelFixture
+{
+    protected RoutingOnnxNerModelRunner Runner { get; private set; } = null!;
+
+    protected EnglishOnnxNerRunner EnglishRunner { get; private set; } = null!;
+
+    protected TamilOnnxNerRunner TamilRunner { get; private set; } = null!;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUpRoutingModels()
+    {
+        var englishPath = RealNerModelPaths.ResolveRepoModelPath();
+        if (!File.Exists(englishPath))
+        {
+            Assert.Ignore(RealNerModelPaths.ModelMissingMessage);
+        }
+
+        var tamilPath = RealTamilNerModelPaths.ResolveRepoModelPath();
+        if (!File.Exists(tamilPath))
+        {
+            Assert.Ignore(RealTamilNerModelPaths.ModelMissingMessage);
+        }
+
+        var options = Options.Create(new PiiRedactionOptions
+        {
+            EnglishOnnxModelPath = englishPath,
+            OnnxModelPath = englishPath,
+            TamilOnnxModelPath = tamilPath,
+            EnableTamilNer = true
+        });
+
+        EnglishRunner = new EnglishOnnxNerRunner(options, NullLogger<EnglishOnnxNerRunner>.Instance);
+        TamilRunner = new TamilOnnxNerRunner(options, NullLogger<TamilOnnxNerRunner>.Instance);
+
+        if (!EnglishRunner.IsModelAvailable)
+        {
+            EnglishRunner.Dispose();
+            TamilRunner.Dispose();
+            Assert.Ignore(RealNerModelPaths.ModelMissingMessage);
+        }
+
+        if (!TamilRunner.IsModelAvailable)
+        {
+            EnglishRunner.Dispose();
+            TamilRunner.Dispose();
+            Assert.Ignore(RealTamilNerModelPaths.ModelMissingMessage);
+        }
+
+        Runner = new RoutingOnnxNerModelRunner(EnglishRunner, TamilRunner, options);
+    }
+
+    [OneTimeTearDown]
+    public void OneTimeTearDownRoutingModels()
+    {
+        EnglishRunner?.Dispose();
+        TamilRunner?.Dispose();
+    }
+}

tests/TestSupport.Shared/RealTamilNerModelFixture.cs

@@ -0,0 +1,45 @@
+using Microsoft.Extensions.Logging.Abstractions;
+using Microsoft.Extensions.Options;
+using PiiRedaction.Core.Configuration;
+using PiiRedaction.Infrastructure.Onnx;
+
+namespace PiiRedaction.Tests.Shared;
+
+/// <summary>
+/// Reuses a single <see cref="TamilOnnxNerRunner"/> per fixture for performance.
+/// Skips all tests in the class when the Tamil ONNX model is missing or cannot be loaded.
+/// </summary>
+public abstract class RealTamilNerModelFixture
+{
+    protected TamilOnnxNerRunner Runner { get; private set; } = null!;
+
+    protected string ModelPath { get; private set; } = null!;
+
+    [OneTimeSetUp]
+    public void OneTimeSetUpTamilModel()
+    {
+        ModelPath = RealTamilNerModelPaths.ResolveRepoModelPath();
+        if (!File.Exists(ModelPath))
+        {
+            Assert.Ignore(RealTamilNerModelPaths.ModelMissingMessage);
+        }
+
+        var options = Options.Create(new PiiRedactionOptions
+        {
+            TamilOnnxModelPath = ModelPath
+        });
+        Runner = new TamilOnnxNerRunner(options, NullLogger<TamilOnnxNerRunner>.Instance);
+
+        if (!Runner.IsModelAvailable)
+        {
+            Runner.Dispose();
+            Assert.Ignore(RealTamilNerModelPaths.ModelMissingMessage);
+        }
+    }
+
+    [OneTimeTearDown]
+    public void OneTimeTearDownTamilModel()
+    {
+        Runner?.Dispose();
+    }
+}

tests/TestSupport.Shared/RealTamilNerModelPaths.cs

@@ -0,0 +1,25 @@
+namespace PiiRedaction.Tests.Shared;
+
+public static class RealTamilNerModelPaths
+{
+    public const string ModelMissingMessage =
+        "Tamil ONNX model not found. Run scripts/download-tamil-ner-model.ps1 from the repository root.";
+
+    public static string ResolveRepoModelPath()
+    {
+        const string relativePath = "models/ta/model.onnx";
+        var directory = new DirectoryInfo(AppContext.BaseDirectory);
+        while (directory is not null)
+        {
+            var candidate = Path.Combine(directory.FullName, relativePath);
+            if (File.Exists(candidate))
+            {
+                return candidate;
+            }
+
+            directory = directory.Parent;
+        }
+
+        return Path.Combine(Environment.CurrentDirectory, relativePath);
+    }
+}