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.

src/PiiRedaction.Core/Configuration/PiiRedactionOptions.cs

@@ -5,4 +5,10 @@ public sealed class PiiRedactionOptions
     public const string SectionName = "PiiRedaction";
 
     public string OnnxModelPath { get; set; } = "models/ner-model.onnx";
+
+    public string EnglishOnnxModelPath { get; set; } = "models/en/ner-model.onnx";
+
+    public string TamilOnnxModelPath { get; set; } = "models/ta/model.onnx";
+
+    public bool EnableTamilNer { get; set; } = true;
 }