Address code review: dispose CTS, flush only on keyframes, include full exception in logs

Co-authored-by: YimingZhanshen <76594627+YimingZhanshen@users.noreply.github.com>

Author: Copilot

AirPlay/Listeners/MirroringListener.cs

@@ -130,7 +130,7 @@ public override async Task OnRawReceivedAsync(TcpClient client, NetworkStream st
                 }
                 catch (Exception e)
                 {
-                    Console.WriteLine($"Mirroring error: {e.Message}");
+                    Console.WriteLine($"Mirroring error: {e}");
                 }
 
                 // Save current session periodically

AirPlay/Services/VideoOutputService.cs

@@ -175,20 +175,22 @@ public void WriteFrame(H264Data data)
 
                 try
                 {
+                    bool isKeyFrame = data.FrameType == 5;
+
                     if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
                     {
                         if (_pipeServer != null && _pipeServer.IsConnected)
                         {
                             _pipeServer.Write(data.Data, 0, data.Length);
-                            _pipeServer.Flush();
+                            if (isKeyFrame) _pipeServer.Flush();
                         }
                     }
                     else
                     {
                         if (_unixPipeStream != null && _unixPipeStream.CanWrite)
                         {
                             _unixPipeStream.Write(data.Data, 0, data.Length);
-                            _unixPipeStream.Flush();
+                            if (isKeyFrame) _unixPipeStream.Flush();
                         }
                     }
 
@@ -250,6 +252,8 @@ public void Dispose()
                 _disposed = true;
 
                 _cts?.Cancel();
+                _cts?.Dispose();
+                _cts = null;
 
                 try
                 {