Fix Twilio dispose issue.

src/Infrastructure/BotSharp.Core/Infrastructures/Websocket/AsyncWebsocketDataResultEnumerator.cs

@@ -31,7 +31,6 @@ public AsyncWebsocketDataResultEnumerator(
     public ValueTask DisposeAsync()
     {
         ArrayPool<byte>.Shared.Return(_buffer, clearArray: true);
-        _webSocket?.Dispose();
         return new ValueTask(Task.CompletedTask);
     }
 

src/Infrastructure/BotSharp.Core/Session/LlmRealtimeSession.cs

@@ -26,7 +26,6 @@ public LlmRealtimeSession(
     public async Task ConnectAsync(Uri uri, Dictionary<string, string>? headers = null, CancellationToken cancellationToken = default)
     {
         _disposed = false;
-        _webSocket?.Dispose();
         _webSocket = new ClientWebSocket();
 
         if (!headers.IsNullOrEmpty())

src/Plugins/BotSharp.Plugin.OpenAI/Providers/Realtime/RealTimeCompletionProvider.cs

@@ -69,7 +69,6 @@ public async Task Connect(
         _model = realtimeSettings.Model;
         var settings = settingsService.GetSetting(Provider, _model);
 
-        _session?.Dispose();
         _session = new LlmRealtimeSession(_services, new ChatSessionOptions
         {
             Provider = Provider,

src/Plugins/BotSharp.Plugin.Twilio/TwilioStreamMiddleware.cs

@@ -23,7 +23,6 @@ public class TwilioStreamMiddleware
 {
     private readonly RequestDelegate _next;
     private readonly ILogger<TwilioStreamMiddleware> _logger;
-    private BotSharpRealtimeSession _session;
 
     public TwilioStreamMiddleware(
         RequestDelegate next,
@@ -52,7 +51,6 @@ public async Task Invoke(HttpContext httpContext)
                 }
                 catch (Exception ex)
                 {
-                    _session?.Dispose();
                     _logger.LogError(ex, $"Error in WebSocket communication: {ex.Message} for conversation {conversationId}");
                 }
                 return;
@@ -64,8 +62,7 @@ public async Task Invoke(HttpContext httpContext)
 
     private async Task HandleWebSocket(IServiceProvider services, string agentId, string conversationId, WebSocket webSocket)
     {
-        _session?.Dispose();
-        _session = new BotSharpRealtimeSession(services, webSocket, new ChatSessionOptions
+        using var session = new BotSharpRealtimeSession(services, webSocket, new ChatSessionOptions
         {
             Provider = "BotSharp Twilio Stream",
             BufferSize = 1024 * 32,
@@ -92,7 +89,7 @@ private async Task HandleWebSocket(IServiceProvider services, string agentId, st
         var routing = services.GetRequiredService<IRoutingService>();
         routing.Context.Push(agentId);
 
-        await foreach (ChatSessionUpdate update in _session.ReceiveUpdatesAsync(CancellationToken.None))
+        await foreach (ChatSessionUpdate update in session.ReceiveUpdatesAsync(CancellationToken.None))
         {
             var receivedText = update?.RawResponse;
             if (string.IsNullOrEmpty(receivedText))
@@ -144,8 +141,7 @@ private async Task HandleWebSocket(IServiceProvider services, string agentId, st
         }
 
         convService.SaveStates();
-        await _session.DisconnectAsync();
-        _session.Dispose();
+        await session.DisconnectAsync();
     }
 
     private async Task ConnectToModel(IRealtimeHub hub, WebSocket webSocket)