chore: remove debug logging from kline pan

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mining-app/lib/presentation/widgets/kline_chart/kline_chart_widget.dart

@@ -538,9 +538,6 @@ class _KlineChartWidgetState extends State<KlineChartWidget> {
         final double maxScroll = math.max(0.0, (widget.klines.length - 0.5) * _candleWidth - drawableWidth / 2);
         // 向右滑 dx>0，scrollX 减小，显示更早的数据
         _scrollX = (_startScrollX - dx).clamp(0.0, maxScroll);
-
-        // DEBUG: 打印滚动信息
-        debugPrint('Pan: dx=$dx, scrollX=$_scrollX, maxScroll=$maxScroll');
       }
     });
   }