.NET: Fixes AgentWithHostedMCP chat fails: ErrorHTTP 404 (: 404) Resource not found (#3856)

* Update packages

* Fix run-request.http format

Author: rogerbarreto

dotnet/samples/HostedAgents/AgentWithHostedMCP/AgentWithHostedMCP.csproj

@@ -35,11 +35,10 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Azure.AI.AgentServer.AgentFramework" Version="1.0.0-beta.5" />
-    <PackageReference Include="Azure.AI.OpenAI" Version="2.7.0-beta.2" />
+    <PackageReference Include="Azure.AI.AgentServer.AgentFramework" Version="1.0.0-beta.6" />
+    <PackageReference Include="Azure.AI.OpenAI" Version="2.8.0-beta.1" />
     <PackageReference Include="Azure.Identity" Version="1.17.1" />
-    <PackageReference Include="Microsoft.Agents.AI.OpenAI" Version="1.0.0-preview.251219.1" />
-    <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="10.1.1-preview.1.25612.2" />
+    <PackageReference Include="Microsoft.Extensions.AI.OpenAI" Version="10.3.0" />
   </ItemGroup>
 
   <!-- Add analyzers with compatible versions -->

dotnet/samples/HostedAgents/AgentWithHostedMCP/Program.cs

@@ -9,7 +9,6 @@
 using Azure.Identity;
 using Microsoft.Agents.AI;
 using Microsoft.Extensions.AI;
-using OpenAI.Responses;
 
 var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
 var deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";
@@ -29,6 +28,7 @@
     new Uri(endpoint),
     new DefaultAzureCredential())
     .GetResponsesClient(deploymentName)
+    .AsIChatClient()
     .CreateAIAgent(
         instructions: "You answer questions by searching the Microsoft Learn content only.",
         name: "MicrosoftLearnAgent",

dotnet/samples/HostedAgents/AgentWithHostedMCP/run-requests.http

@@ -7,13 +7,15 @@ GET {{host}}/readiness
 ### Simple string input - Ask about MCP Tools
 POST {{endpoint}}
 Content-Type: application/json
+
 {
     "input": "Please summarize the Azure AI Agent documentation related to MCP Tool calling?"
 }
 
 ### Explicit input - Ask about Agent Framework
 POST {{endpoint}}
 Content-Type: application/json
+
 {
     "input": [
         {