style: Dashboard 看板表格行高与图表微调

训练任务表格行高加大提升可读性，登录时长图表留白与标签位置调整避免溢出，回归断言同步。

frontend/src/views/dashboard/DashboardView.vue

@@ -253,7 +253,7 @@ const loginDurationStats: LoginDurationStat[] = [
 
 const loginDurationChartOption = computed<EChartsOption>(() => ({
   animationDuration: 500,
-  grid: { top: 8, right: 40, bottom: 6, left: 8, containLabel: true },
+  grid: { top: 8, right: 60, bottom: 6, left: 8, containLabel: true },
   tooltip: {
     trigger: 'axis',
     axisPointer: { type: 'shadow' },
@@ -261,7 +261,7 @@ const loginDurationChartOption = computed<EChartsOption>(() => ({
   },
   xAxis: {
     type: 'value',
-    max: Math.ceil(Math.max(...loginDurationStats.map((user) => user.duration)) / 10) * 10,
+    max: Math.ceil(Math.max(...loginDurationStats.map((user) => user.duration)) * 1.15 / 10) * 10,
     splitNumber: 4,
     axisLabel: { color: '#94a3b8', fontSize: 11, formatter: '{value}h' },
     axisLine: { show: false },
@@ -284,7 +284,7 @@ const loginDurationChartOption = computed<EChartsOption>(() => ({
       barMaxWidth: 18,
       barCategoryGap: '34%',
       itemStyle: { color: '#4f46e5', borderRadius: [0, 4, 4, 0] },
-      label: { show: true, position: 'right', distance: 8, color: '#64748b', fontSize: 11, formatter: '{c} 小时' },
+      label: { show: true, position: 'insideRight', distance: 6, color: '#ffffff', fontSize: 11, formatter: '{c} 小时' },
     },
   ],
 }))
@@ -798,8 +798,8 @@ function viewTask(task: DashboardTask) {
 
   th,
   td {
-    height: 42px;
-    padding: 6px 10px;
+    height: 50px;
+    padding: 8px 10px;
     border-top: 1px solid #eef2f7;
     text-align: left;
     vertical-align: middle;
@@ -807,7 +807,7 @@ function viewTask(task: DashboardTask) {
   }
 
   th {
-    height: 36px;
+    height: 38px;
     background: #f8fafc;
     color: #475569;
     font-weight: 600;
@@ -925,12 +925,12 @@ function viewTask(task: DashboardTask) {
   .tasks-table {
     th,
     td {
-      height: 36px;
-      padding: 4px 8px;
+      height: 42px;
+      padding: 6px 8px;
     }
 
     th {
-      height: 32px;
+      height: 34px;
     }
   }
 }