Add C# API for homophone replacer (#2165)

+/// Copyright (c)  2025  Xiaomi Corporation (authors: Fangjun Kuang)
+
+using System.Runtime.InteropServices;
+
+namespace SherpaOnnx
+{
+    [StructLayout(LayoutKind.Sequential)]
+    public struct HomophoneReplacerConfig
+    {
+        public HomophoneReplacerConfig()
+        {
+          DictDir = "";
+          Lexicon = "";
+          RuleFsts = "";
+        }
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string DictDir;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string Lexicon;
+
+        [MarshalAs(UnmanagedType.LPStr)]
+        public string RuleFsts;
+    }
+}

@@ -20,6 +20,7 @@ namespace SherpaOnnx
             RuleFsts = "";
             RuleFars = "";
             BlankPenalty = 0.0F;
+            Hr = new HomophoneReplacerConfig();
         }
         public FeatureConfig FeatConfig;
         public OfflineModelConfig ModelConfig;
@@ -42,5 +43,7 @@ namespace SherpaOnnx
         public string RuleFars;
 
         public float BlankPenalty;
+
+        public HomophoneReplacerConfig Hr;
     }
 }

@@ -28,6 +28,7 @@ namespace SherpaOnnx
             BlankPenalty = 0.0F;
             HotwordsBuf = "";
             HotwordsBufSize = 0;
+            Hr = new HomophoneReplacerConfig();
         }
         public FeatureConfig FeatConfig;
         public OnlineModelConfig ModelConfig;
@@ -79,5 +80,7 @@ namespace SherpaOnnx
         public string HotwordsBuf;
 
         public int HotwordsBufSize;
+
+        public HomophoneReplacerConfig Hr;
     }
 }