修复预览线条颜色，确保所有绘图线条为红色

src/client/mobile/components/stock/components/stock-chart/src/lib/drawing/ChartDrawingTools.ts

@@ -412,7 +412,8 @@ export class ChartDrawingTools {
             lineStyle: {
               width: 1,
               type: 'dashed',
-              color: '#999'
+              color: '#ff0000', // 红色
+              opacity: 1 // 透明度100%
             },
             data: [previewData]
           }
@@ -433,7 +434,8 @@ export class ChartDrawingTools {
         yAxis: this.tempLine.points[0].yValue,
         lineStyle: {
           type: 'dashed',
-          color: '#999'
+          color: '#ff0000', // 红色
+          opacity: 1 // 透明度100%
         }
       });
     } else if (this.tempLine.points.length === 2) {
@@ -462,7 +464,8 @@ export class ChartDrawingTools {
           lineStyle: {
             width: 1,
             type: 'dashed',
-            color: '#999'
+            color: '#ff0000', // 红色
+            opacity: 1 // 透明度100%
           },
           data: previewData
         }