style: 登录时长图表轴上限提取与标签外置

横轴上限提取为 loginDurationAxisMax 常量，标签位置统一回到柱体右侧灰色展示，回归断言同步。

frontend/scripts/regression-dashboard.mjs

@@ -54,7 +54,8 @@ assert.match(dashboardSource, /class=["']user-stats-row["'][\s\S]*?用户操作
 assert.match(dashboardSource, /class=["']duration-chart["'][\s\S]*?loginDurationChartOption/, '登录时长应使用 ECharts 图表展示')
 assert.match(dashboardSource, /const loginDurationChartOption[\s\S]*?type:\s*['"]bar['"][\s\S]*?formatter:\s*['"]\{c\} 小时['"]/, '登录时长应以横向柱状图展示具体小时数')
 assert.match(dashboardSource, /const operationChartOption[\s\S]*?position:\s*['"]outside['"][\s\S]*?labelLine:\s*\{[\s\S]*?show:\s*true/, '饼图应以外侧引导线标注操作名称')
-assert.match(dashboardSource, /const loginDurationChartOption[\s\S]*?grid:\s*\{\s*top:\s*8,\s*right:\s*12,\s*bottom:\s*6,\s*left:\s*8,[\s\S]*?max:\s*Math\.ceil\(Math\.max[\s\S]*?position:\s*['"]insideRight['"]/, '登录时长图应收紧左右边距、按数据范围拉伸，并将数值置于柱内')
+assert.match(dashboardSource, /const loginDurationAxisMax\s*=\s*Math\.ceil\([\s\S]*?Math\.max/, '登录时长图应按数据范围计算横轴上限')
+assert.match(dashboardSource, /const loginDurationChartOption[\s\S]*?position:\s*['"]right['"][\s\S]*?formatter:\s*['"]\{c\} 小时['"]/, '登录时长标签应统一显示在柱体外侧')
 assert.match(dashboardSource, /\.user-stats-row\s*\{[\s\S]*?repeat\(3,\s*minmax\(0,\s*1fr\)\)/, '宽屏用户统计卡片应保持三列')
 assert.match(dashboardSource, /@media\s*\(max-width:\s*1180px\)[\s\S]*?\.user-stats-row\s*\{[\s\S]*?repeat\(2,\s*minmax\(0,\s*1fr\)\)/, '中等宽度应将用户统计卡片降为两列')
 assert.match(dashboardSource, /@media\s*\(max-width:\s*720px\)[\s\S]*?\.user-stats-row\s*\{[\s\S]*?grid-template-columns:\s*1fr;/, '窄屏应将用户统计卡片降为单列')