feat(dashboard): 仪表盘模块审计重构 — 权限校验 + i18n + 逻辑抽离

基于 dashboard-audit-report.md 审计结论，对仪表盘模块进行 P0/P1 级修复：

- 新增 4 个 dashboard 权限点（DASHBOARD_ADMIN/TEACHER/STUDENT/PARENT_READ），补充到 permissions.ts 和角色-权限映射

- 新建 actions.ts：4 个 Server Action 均调用 requirePermission() 校验权限，消除 admin 页面零鉴权、teacher/student/parent 仅 requireAuth 的安全隐患

- 根重定向页 /dashboard 改用 resolvePermissions() + 权限点判断，不再 role === xxx 硬编码

- 新建 lib/dashboard-utils.ts：抽取 toWeekday / countStudentAssignments / sortUpcomingAssignments / filterTodaySchedule / computeTeacherMetrics / getGreetingKey 纯函数，与 UI 分离，便于单测

- 新建 messages/{zh-CN,en}/dashboard.json 翻译文件，i18n request.ts 加载 dashboard 命名空间；所有视图组件接入 useTranslations / getTranslations，消除中英混杂硬编码

- 重构 4 个角色 page.tsx：通过 actions 获取数据，generateMetadata 使用 i18n

- 同步更新架构图 004 / 005 文档（dashboard exports / permissions / 文件清单）

src/modules/dashboard/components/teacher-dashboard/teacher-dashboard-header.tsx

@@ -1,6 +1,8 @@
 "use client"
 
+import { useTranslations } from "next-intl"
 import { formatLongDate } from "@/shared/lib/utils"
+import { getGreetingKey } from "@/modules/dashboard/lib/dashboard-utils"
 import { TeacherQuickActions } from "./teacher-quick-actions"
 
 interface TeacherDashboardHeaderProps {
@@ -8,18 +10,17 @@ interface TeacherDashboardHeaderProps {
 }
 
 export function TeacherDashboardHeader({ teacherName }: TeacherDashboardHeaderProps) {
+  const t = useTranslations("dashboard")
   const today = formatLongDate(new Date())
-  const hour = new Date().getHours()
-  let greeting = "欢迎回来"
-  if (hour < 12) greeting = "早上好"
-  else if (hour < 18) greeting = "下午好"
-  else greeting = "晚上好"
+  const greetingKey = getGreetingKey(new Date())
 
   return (
     <div className="flex flex-col justify-between space-y-4 md:flex-row md:items-center md:space-y-0">
       <div>
-        <h2 className="text-2xl font-bold tracking-tight">{greeting}，{teacherName}</h2>
-        <p className="text-muted-foreground">今天是 {today}，以下是今日概览。</p>
+        <h2 className="text-2xl font-bold tracking-tight">
+          {t(`greeting.${greetingKey}`)}，{teacherName}
+        </h2>
+        <p className="text-muted-foreground">{t("greeting.todayIs", { date: today })}</p>
       </div>
       <TeacherQuickActions />
     </div>

src/modules/dashboard/components/teacher-dashboard/teacher-dashboard-view.tsx

@@ -1,4 +1,7 @@
-import type { TeacherDashboardData, TeacherTodayScheduleItem } from "@/modules/dashboard/types"
+import type { TeacherDashboardData } from "@/modules/dashboard/types"
+import type { TeacherDashboardMetrics } from "@/modules/dashboard/lib/dashboard-utils"
+import { getTranslations } from "next-intl/server"
+import type { TeacherTodoItem } from "./teacher-todo-card"
 
 import { TeacherClassesCard } from "./teacher-classes-card"
 import { TeacherDashboardHeader } from "./teacher-dashboard-header"
@@ -7,52 +10,36 @@ import { RecentSubmissions } from "./recent-submissions"
 import { TeacherSchedule } from "./teacher-schedule"
 import { TeacherStats } from "./teacher-stats"
 import { TeacherGradeTrends } from "./teacher-grade-trends"
-import { TeacherTodoCard, type TeacherTodoItem } from "./teacher-todo-card"
+import { TeacherTodoCard } from "./teacher-todo-card"
 
-const toWeekday = (d: Date): 1 | 2 | 3 | 4 | 5 | 6 | 7 => {
-  const day = d.getDay()
-  return (day === 0 ? 7 : day) as 1 | 2 | 3 | 4 | 5 | 6 | 7
+interface TeacherDashboardViewProps {
+  data: TeacherDashboardData & { metrics: TeacherDashboardMetrics }
 }
 
-export function TeacherDashboardView({ data }: { data: TeacherDashboardData }) {
-  const todayWeekday = toWeekday(new Date())
+export async function TeacherDashboardView({ data }: TeacherDashboardViewProps) {
+  const t = await getTranslations("dashboard")
+  const { metrics } = data
 
-  const classNameById = new Map(data.classes.map((c) => [c.id, c.name] as const))
-  const todayScheduleItems: TeacherTodayScheduleItem[] = data.schedule
-    .filter((s) => s.weekday === todayWeekday)
-    .sort((a, b) => a.startTime.localeCompare(b.startTime))
-    .map((s): TeacherTodayScheduleItem => ({
-      id: s.id,
-      classId: s.classId,
-      className: classNameById.get(s.classId) ?? "Class",
-      course: s.course,
-      startTime: s.startTime,
-      endTime: s.endTime,
-      location: s.location ?? null,
-    }))
-
-  const submittedSubmissions = data.submissions.filter((s) => Boolean(s.submittedAt))
-  const toGradeCount = submittedSubmissions.filter((s) => s.status === "submitted").length
-
-  const submissionsToGrade = submittedSubmissions
-    .filter(s => s.status === "submitted")
-    .sort((a, b) => (a.submittedAt ? new Date(a.submittedAt).getTime() : 0) - (b.submittedAt ? new Date(b.submittedAt).getTime() : 0))
-    .slice(0, 6);
-
-  const activeAssignmentsCount = data.assignments.filter(a => a.status === "published").length
-  
-  const totalTrendScore = data.gradeTrends.reduce((acc, curr) => acc + curr.averageScore, 0)
-  const averageScore = data.gradeTrends.length > 0 ? totalTrendScore / data.gradeTrends.length : 0
-
-  const totalSubmissions = data.gradeTrends.reduce((acc, curr) => acc + curr.submissionCount, 0)
-  const totalPotentialSubmissions = data.gradeTrends.reduce((acc, curr) => acc + curr.totalStudents, 0)
-  const submissionRate = totalPotentialSubmissions > 0 ? (totalSubmissions / totalPotentialSubmissions) * 100 : 0
-
-  // 待办聚合
+  // 待办聚合（使用预计算指标）
   const todoItems: TeacherTodoItem[] = [
-    { label: "待批改作业", count: toGradeCount, href: "/teacher/homework/submissions", variant: toGradeCount > 0 ? "urgent" : "normal" },
-    { label: "今日待考勤", count: todayScheduleItems.length, href: "/teacher/attendance/sheet", variant: "info" },
-    { label: "进行中作业", count: activeAssignmentsCount, href: "/teacher/homework/assignments", variant: "normal" },
+    {
+      label: t("todo.toGrade"),
+      count: metrics.toGradeCount,
+      href: "/teacher/homework/submissions",
+      variant: metrics.toGradeCount > 0 ? "urgent" : "normal",
+    },
+    {
+      label: t("todo.todayAttendance"),
+      count: metrics.todayScheduleItems.length,
+      href: "/teacher/attendance/sheet",
+      variant: "info",
+    },
+    {
+      label: t("todo.activeAssignments"),
+      count: metrics.activeAssignmentsCount,
+      href: "/teacher/homework/assignments",
+      variant: "normal",
+    },
   ]
 
   return (
@@ -60,34 +47,34 @@ export function TeacherDashboardView({ data }: { data: TeacherDashboardData }) {
       <TeacherDashboardHeader teacherName={data.teacherName} />
 
       <TeacherStats
-        toGradeCount={toGradeCount}
-        activeAssignmentsCount={activeAssignmentsCount}
-        averageScore={averageScore}
-        submissionRate={submissionRate}
+        toGradeCount={metrics.toGradeCount}
+        activeAssignmentsCount={metrics.activeAssignmentsCount}
+        averageScore={metrics.averageScore}
+        submissionRate={metrics.submissionRate}
       />
 
       <div className="grid gap-6 lg:grid-cols-12">
         {/* 移动端优先展示：今日课表 → 待办 → 待批改 */}
         <div className="flex flex-col gap-6 lg:col-span-8">
-            <div className="lg:hidden">
-              <TeacherSchedule items={todayScheduleItems} />
-            </div>
-            <TeacherTodoCard items={todoItems} />
-            <TeacherGradeTrends trends={data.gradeTrends} />
-            <RecentSubmissions 
-                submissions={submissionsToGrade} 
-                title="待批改"
-                emptyTitle="全部批改完成！"
-                emptyDescription="暂无待批改的提交。"
-            />
+          <div className="lg:hidden">
+            <TeacherSchedule items={metrics.todayScheduleItems} />
+          </div>
+          <TeacherTodoCard items={todoItems} />
+          <TeacherGradeTrends trends={data.gradeTrends} />
+          <RecentSubmissions
+            submissions={metrics.submissionsToGrade}
+            title={t("sections.pendingGrading")}
+            emptyTitle={t("empty.allGraded")}
+            emptyDescription={t("empty.allGradedDesc")}
+          />
         </div>
-        
+
         <div className="flex flex-col gap-6 lg:col-span-4">
-            <div className="hidden lg:block">
-              <TeacherSchedule items={todayScheduleItems} />
-            </div>
-            <TeacherHomeworkCard assignments={data.assignments} />
-            <TeacherClassesCard classes={data.classes} />
+          <div className="hidden lg:block">
+            <TeacherSchedule items={metrics.todayScheduleItems} />
+          </div>
+          <TeacherHomeworkCard assignments={data.assignments} />
+          <TeacherClassesCard classes={data.classes} />
         </div>
       </div>
     </div>

src/modules/dashboard/components/teacher-dashboard/teacher-stats.tsx

@@ -1,27 +1,30 @@
-import { FileCheck, PenTool, TrendingUp, BarChart } from "lucide-react";
-import { StatCard } from "@/shared/components/ui/stat-card";
+import { FileCheck, PenTool, TrendingUp, BarChart } from "lucide-react"
+import { getTranslations } from "next-intl/server"
+import { StatCard } from "@/shared/components/ui/stat-card"
 
 interface TeacherStatsProps {
-  toGradeCount: number;
-  activeAssignmentsCount: number;
-  averageScore: number;
-  submissionRate: number;
-  isLoading?: boolean;
+  toGradeCount: number
+  activeAssignmentsCount: number
+  averageScore: number
+  submissionRate: number
+  isLoading?: boolean
 }
 
-export function TeacherStats({
+export async function TeacherStats({
   toGradeCount,
   activeAssignmentsCount,
   averageScore,
   submissionRate,
   isLoading = false,
 }: TeacherStatsProps) {
+  const t = await getTranslations("dashboard")
+
   return (
     <div className="grid gap-4 md:grid-cols-2 lg:grid-cols-4">
       <StatCard
-        title="Needs Grading"
+        title={t("stats.needsGrading")}
         value={String(toGradeCount)}
-        description="Submissions pending review"
+        description={t("stats.submissionsPendingReview")}
         icon={FileCheck}
         href="/teacher/homework/submissions?status=submitted"
         highlight={toGradeCount > 0}
@@ -29,32 +32,32 @@ export function TeacherStats({
         isLoading={isLoading}
       />
       <StatCard
-        title="Active Assignments"
+        title={t("stats.activeAssignments")}
         value={String(activeAssignmentsCount)}
-        description="Published and ongoing"
+        description={t("stats.publishedAndOngoing")}
         icon={PenTool}
         href="/teacher/homework/assignments?status=published"
         color="text-blue-500"
         isLoading={isLoading}
       />
       <StatCard
-        title="Average Score"
+        title={t("stats.averageScore")}
         value={`${Math.round(averageScore)}%`}
-        description="Across recent assignments"
+        description={t("stats.acrossRecentAssignments")}
         icon={TrendingUp}
         href="#grade-trends"
         color="text-emerald-500"
         isLoading={isLoading}
       />
       <StatCard
-        title="Submission Rate"
+        title={t("stats.submissionRate")}
         value={`${Math.round(submissionRate)}%`}
-        description="Overall completion rate"
+        description={t("stats.overallCompletionRate")}
         icon={BarChart}
         href="#grade-trends"
         color="text-purple-500"
         isLoading={isLoading}
       />
     </div>
-  );
+  )
 }

src/modules/dashboard/components/teacher-dashboard/teacher-todo-card.tsx

@@ -0,0 +1,82 @@
+import Link from "next/link"
+import { getTranslations } from "next-intl/server"
+import { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
+import { ClipboardCheck, CalendarCheck, FileEdit, AlertCircle, ChevronRight } from "lucide-react"
+import { cn } from "@/shared/lib/utils"
+
+export interface TeacherTodoItem {
+  label: string
+  count: number
+  href: string
+  variant: "urgent" | "normal" | "info"
+}
+
+interface TeacherTodoCardProps {
+  items: TeacherTodoItem[]
+}
+
+const VARIANT_STYLES: Record<TeacherTodoItem["variant"], { icon: typeof AlertCircle; iconColor: string; badge: string }> = {
+  urgent: { icon: AlertCircle, iconColor: "text-destructive", badge: "bg-destructive text-destructive-foreground" },
+  normal: { icon: ClipboardCheck, iconColor: "text-amber-500", badge: "bg-amber-500 text-white" },
+  info: { icon: CalendarCheck, iconColor: "text-blue-500", badge: "bg-blue-500 text-white" },
+}
+
+export async function TeacherTodoCard({ items }: TeacherTodoCardProps) {
+  const t = await getTranslations("dashboard")
+  const hasItems = items.some((item) => item.count > 0)
+  const totalPending = items.reduce((acc, item) => acc + (item.count > 0 ? 1 : 0), 0)
+
+  return (
+    <Card>
+      <CardHeader className="flex flex-row items-center justify-between pb-3">
+        <CardTitle className="flex items-center gap-2 text-base">
+          <FileEdit className="h-4 w-4 text-muted-foreground" aria-hidden="true" />
+          {t("todo.title")}
+          {totalPending > 0 && (
+            <span className="inline-flex h-5 min-w-5 items-center justify-center rounded-full bg-primary px-1.5 text-xs font-medium text-primary-foreground tabular-nums">
+              {totalPending}
+            </span>
+          )}
+        </CardTitle>
+      </CardHeader>
+      <CardContent>
+        {!hasItems ? (
+          <div className="flex h-24 items-center justify-center text-sm text-muted-foreground">
+            <CalendarCheck className="mr-2 h-4 w-4" aria-hidden="true" />
+            {t("todo.empty")}
+          </div>
+        ) : (
+          <div className="space-y-1">
+            {items
+              .filter((item) => item.count > 0)
+              .sort((a, b) => (a.variant === "urgent" ? -1 : 1) - (b.variant === "urgent" ? -1 : 1))
+              .map((item, idx) => {
+                const style = VARIANT_STYLES[item.variant]
+                const Icon = style.icon
+                return (
+                  <Link
+                    key={idx}
+                    href={item.href}
+                    className="group flex items-center justify-between rounded-md border border-transparent px-3 py-2 hover:bg-muted/50 hover:border-border transition-colors"
+                  >
+                    <div className="flex items-center gap-2 min-w-0">
+                      <Icon className={cn("h-4 w-4 shrink-0", style.iconColor)} aria-hidden="true" />
+                      <span className="text-sm font-medium truncate group-hover:text-primary transition-colors">
+                        {item.label}
+                      </span>
+                    </div>
+                    <div className="flex items-center gap-2 shrink-0">
+                      <span className={cn("inline-flex h-5 min-w-5 items-center justify-center rounded-full px-1.5 text-xs font-medium tabular-nums", style.badge)}>
+                        {item.count}
+                      </span>
+                      <ChevronRight className="h-3.5 w-3.5 text-muted-foreground opacity-0 group-hover:opacity-100 transition-opacity" aria-hidden="true" />
+                    </div>
+                  </Link>
+                )
+              })}
+          </div>
+        )}
+      </CardContent>
+    </Card>
+  )
+}