style(ops): 上月趋势线改实线，热力图增加颜色细分层级

- 工单趋势图：上月新增线条去掉虚线(dashed)，改为实线
- 时段热力图：颜色从6级扩展到9级(#f0f5ff→#061178)，splitNumber 5→8，低值与高值区分更明显

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/web-antd/src/views/ops/cleaning/work-order/dashboard/index.vue

@@ -248,7 +248,6 @@ function getTrendChartOptions(): ECOption {
         smooth: true,
         symbol: 'circle',
         symbolSize: 6,
-        lineStyle: { type: 'dashed' },
         areaStyle: {
           opacity: 0.1,
           color: {
@@ -571,15 +570,18 @@ function getHeatmapChartOptions(): ECOption {
       itemHeight: 50,
       inRange: {
         color: [
-          '#e6f7ff',
-          '#bae7ff',
-          '#91d5ff',
-          '#69c0ff',
-          '#40a9ff',
-          '#1677ff',
+          '#f0f5ff',
+          '#d6e4ff',
+          '#adc6ff',
+          '#85a5ff',
+          '#597ef7',
+          '#2f54eb',
+          '#1d39c4',
+          '#10239e',
+          '#061178',
         ],
       },
-      splitNumber: 5,
+      splitNumber: 8,
       show: false,
     },
     series: [