R59 A1-A6：极简考勤打卡

- 新增 AttendanceRecord 与 AttendancePolicy 模型
- 上下班打卡、今日状态、月度统计端点
- 考勤管理页面（我的/团队/设置三 Tab）
- 移动端快速打卡入口
- 管理员补卡与审计日志
- 单测覆盖打卡幂等、迟到计算、工时计算、权限边界

server/src/services/featureFlags/index.js

@@ -11,6 +11,7 @@ const FEATURE_FLAG_KEYS = {
   workflowDefinitionAdmin: "workflow_definition_admin_v1",
   cutoverConsole: "cutover_console_v1",
   presenceBoard: "presence_board_v1",
+  attendance: "attendance_v1",
   weeklyReport: "weekly_report_v1",
   employeeLifecycle: "employee_lifecycle_v1",
   todoBoard: "todo_board_v1",
@@ -122,6 +123,10 @@ function resolveEnvGate(config, flagKey) {
     return Boolean(config.presenceBoardEnabled);
   }
 
+  if (flagKey === FEATURE_FLAG_KEYS.attendance) {
+    return Boolean(config.attendanceEnabled);
+  }
+
   if (flagKey === FEATURE_FLAG_KEYS.weeklyReport) {
     return Boolean(config.weeklyReportEnabled);
   }