style(theme): 客户端切换深色视觉风格

lib/pages/player/widgets/seek_progress_bar.dart

@@ -233,7 +233,7 @@ class _SeekProgressBarState extends State<SeekProgressBar> {
                   '${_format(previewPosition)} / ${_format(video.duration)}',
                   textAlign: TextAlign.center,
                   style: const TextStyle(
-                    color: Colors.white,
+                    color: AppColors.onPrimary,
                     fontSize: 14,
                     fontWeight: FontWeight.w600,
                     height: 1.2,