Fix slider postion not affecting playback

src/AudioPlayer.cpp

@@ -69,7 +69,7 @@ void AudioPlayer::play(std::shared_ptr<QByteArray> audioData)
 	buffer->setParent(this);
 
 	// Use QMediaPlayer::setSourceDevice for in-memory playback
-	mediaPlayer->setSourceDevice(buffer, QUrl("memory://audio.wav"));
+	mediaPlayer->setSourceDevice(buffer);
 	mediaPlayer->play();
 
 	// Start position timer

src/MainWindow.cpp

@@ -61,6 +61,7 @@ MainWindow::MainWindow(QWidget *parent)
 	connect(ui->actionLoadPlaylist, &QAction::triggered, this, &MainWindow::onActionLoadPlaylist);
 	connect(ui->actionAppendPlaylist, &QAction::triggered, this, &MainWindow::onActionAppendPlaylist);
 	connect(ui->actionSaveSong, &QAction::triggered, this, &MainWindow::onActionSaveSong);
+	connect(ui->positionSlider, &QSlider::sliderMoved, this, &MainWindow::onPositionSliderSliderMoved);
 	connect(ui->actionQuit, &QAction::triggered, this, [this]()
 	{
 		close();