feat(admin): 补全 admin 模块核心功能与产品体验优化

修复 v4 报告中的 13 个产品体验问题：新增用户管理列表页和系统设置页，重组导航菜单并补充缺失入口，增加角色切换机制，Dashboard 增加快捷操作和 recharts 趋势图表，考勤增加统计概览，排课增加课表网格视图，统一 Toast 操作反馈，同步更新架构文档

src/modules/attendance/components/attendance-stats-cards.tsx

@@ -0,0 +1,80 @@
+import { Users, CheckCircle2, XCircle, Clock, LogOut, FileText } from "lucide-react"
+
+import { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
+
+interface AttendanceStatsCardsProps {
+  stats: {
+    totalRecords: number
+    presentCount: number
+    absentCount: number
+    lateCount: number
+    earlyLeaveCount: number
+    excusedCount: number
+    attendanceRate: number
+  }
+}
+
+export function AttendanceStatsCards({ stats }: AttendanceStatsCardsProps) {
+  const cards = [
+    {
+      title: "总记录数",
+      value: stats.totalRecords,
+      icon: FileText,
+      color: "text-blue-500",
+      bgColor: "bg-blue-500/10",
+    },
+    {
+      title: "出勤",
+      value: stats.presentCount,
+      icon: CheckCircle2,
+      color: "text-green-500",
+      bgColor: "bg-green-500/10",
+    },
+    {
+      title: "缺勤",
+      value: stats.absentCount,
+      icon: XCircle,
+      color: "text-red-500",
+      bgColor: "bg-red-500/10",
+    },
+    {
+      title: "迟到",
+      value: stats.lateCount,
+      icon: Clock,
+      color: "text-yellow-500",
+      bgColor: "bg-yellow-500/10",
+    },
+    {
+      title: "早退",
+      value: stats.earlyLeaveCount,
+      icon: LogOut,
+      color: "text-orange-500",
+      bgColor: "bg-orange-500/10",
+    },
+    {
+      title: "出勤率",
+      value: `${stats.attendanceRate}%`,
+      icon: Users,
+      color: "text-primary",
+      bgColor: "bg-primary/10",
+    },
+  ]
+
+  return (
+    <div className="grid gap-4 md:grid-cols-3 lg:grid-cols-6">
+      {cards.map((card) => (
+        <Card key={card.title} className="shadow-none">
+          <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
+            <CardTitle className="text-sm font-medium">{card.title}</CardTitle>
+            <div className={`flex h-8 w-8 items-center justify-center rounded-md ${card.bgColor}`}>
+              <card.icon className={`h-4 w-4 ${card.color}`} />
+            </div>
+          </CardHeader>
+          <CardContent>
+            <div className="text-2xl font-bold tabular-nums">{card.value}</div>
+          </CardContent>
+        </Card>
+      ))}
+    </div>
+  )
+}

src/modules/attendance/data-access.ts

@@ -271,3 +271,39 @@ export async function upsertAttendanceRules(data: AttendanceRuleInput): Promise<
   })
   return id
 }
+
+export type AttendanceOverviewStats = {
+  totalRecords: number
+  presentCount: number
+  absentCount: number
+  lateCount: number
+  earlyLeaveCount: number
+  excusedCount: number
+  attendanceRate: number
+}
+
+export async function getAttendanceStats(params: {
+  scope: DataScope
+  currentUserId: string
+  classId?: string
+  date?: string
+}): Promise<AttendanceOverviewStats> {
+  // 简化实现：基于已有查询统计
+  const records = await getAttendanceRecords(params)
+  const items = records.items
+  const total = items.length
+  const present = items.filter((r) => r.status === "present").length
+  const absent = items.filter((r) => r.status === "absent").length
+  const late = items.filter((r) => r.status === "late").length
+  const earlyLeave = items.filter((r) => r.status === "early_leave").length
+  const excused = items.filter((r) => r.status === "excused").length
+  return {
+    totalRecords: total,
+    presentCount: present,
+    absentCount: absent,
+    lateCount: late,
+    earlyLeaveCount: earlyLeave,
+    excusedCount: excused,
+    attendanceRate: total > 0 ? Math.round((present / total) * 1000) / 10 : 0,
+  }
+}