Update OnnxRuntimeGenAIChatClient to M.E.AI.Abstractions 9.7.0 (#1612)

Author: stephentoub

nuget/Microsoft.ML.OnnxRuntimeGenAI.Managed.nuspec

@@ -14,19 +14,19 @@
     <tags>ONNX;ONNX Runtime;ONNX Runtime Gen AI;Machine Learning</tags>
     <dependencies>
       <group targetFramework="net8.0">
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.5.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.7.0" />
       </group>
       <group targetFramework="netstandard2.0">
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.5.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.7.0" />
       </group>
       <group targetFramework="net8.0-android31.0">
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.5.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.7.0" />
       </group>
       <group targetFramework="net8.0-ios15.4">
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.5.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.7.0" />
       </group>
       <group targetFramework="net8.0-maccatalyst14.0">
-        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.5.0" />
+        <dependency id="Microsoft.Extensions.AI.Abstractions" version="9.7.0" />
       </group>
     </dependencies>
   </metadata>

src/csharp/Microsoft.ML.OnnxRuntimeGenAI.csproj

@@ -123,7 +123,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.5.0" />
+    <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="9.7.0" />
   </ItemGroup>
 
 </Project>

src/csharp/OnnxRuntimeGenAIChatClient.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
+using Microsoft.Extensions.AI;
 using System;
 using System.Collections.Generic;
 using System.Runtime.CompilerServices;
@@ -9,7 +10,6 @@
 using System.Text.Json.Serialization;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Extensions.AI;
 
 #nullable enable
 
@@ -276,6 +276,15 @@ private string FormatPromptDefault(IEnumerable<ChatMessage> messages, ChatOption
         StringBuilder prompt = new();
         string separator = "";
         prompt.Append('[');
+
+        if (options?.Instructions is { } instructions)
+        {
+            m.Role = ChatRole.System.Value;
+            m.Content = instructions;
+            prompt.Append(JsonSerializer.Serialize(m, OnnxJsonContext.Default.SerializableMessage));
+            separator = ",";
+        }
+
         foreach (var message in messages)
         {
             if (message.Text is string text)
@@ -288,6 +297,7 @@ private string FormatPromptDefault(IEnumerable<ChatMessage> messages, ChatOption
                 prompt.Append(JsonSerializer.Serialize(m, OnnxJsonContext.Default.SerializableMessage));
             }
         }
+
         prompt.Append(']');
 
         return _tokenizer.ApplyChatTemplate(