refactor(grades,diagnostic): 完成成绩和学情诊断模块审计 P1+P2 改进项

P1-1: 抽取 stats-service.ts，将 8 个统计计算纯函数从 data-access 层分离 P1-5: 创建 WidgetBoundary 组件 + 补齐 teacher 路由 loading.tsx/error.tsx (14 文件) P1-6: 同步架构图文档 004/005，新增 stats-service 与 widget-boundary 节点 P2-1: 补充 a11y ARIA 属性（5 图表 role=img + aria-label，2 表格 caption，3 列表 role=list，3 按钮 aria-label） P2-3: 修复班级报告 studentId 字段语义错误（schema 改为可空 + 迁移 + 代码适配） P2-4: 修复 grade_managed scope 返回空数据（改为子查询 classes 表按 gradeId 过滤） P2-5: 新增 /parent/diagnostic/ 页面（多子女学情诊断聚合 + loading + error） P2-6: 统一 SearchParams 工具（student/grades 和 management/grade/insights 改用 @/shared/lib/search-params）
2026-06-22 17:07:32 +08:00
parent e997abaf5e
commit 5f3a1a4662
41 changed files with 9043 additions and 381 deletions
--- a/src/app/(dashboard)/management/grade/insights/page.tsx
+++ b/src/app/(dashboard)/management/grade/insights/page.tsx
@@ -1,3 +1,7 @@
+import type { Metadata } from "next"
+import type { JSX } from "react"
+
+import { getTranslations } from "next-intl/server"
 import { requirePermission } from "@/shared/lib/auth-guard"
 import { Permissions } from "@/shared/types/permissions"
 import { getTeacherIdForMutations } from "@/modules/classes/data-access"
@@ -11,22 +15,23 @@ import { Button } from "@/shared/components/ui/button"
 import { Table, TableBody, TableCell, TableHead, TableHeader, TableRow } from "@/shared/components/ui/table"
 import { BarChart3 } from "lucide-react"
 import { formatDate } from "@/shared/lib/utils"
+import { getParam, type SearchParams } from "@/shared/lib/search-params"

 export const dynamic = "force-dynamic"

-type SearchParams = { [key: string]: string | string[] | undefined }
-
-const getParam = (params: SearchParams, key: string) => {
-  const v = params[key]
-  if (typeof v === "string") return v
-  if (Array.isArray(v)) return v[0]
-  return undefined
-}
-
 const formatScore = (v: number | null, digits = 1) => (typeof v === "number" && Number.isFinite(v) ? v.toFixed(digits) : "-")

-export default async function TeacherGradeInsightsPage({ searchParams }: { searchParams: Promise<SearchParams> }) {
+export async function generateMetadata(): Promise<Metadata> {
+  const t = await getTranslations("school")
+  return {
+    title: `${t("classManagement.grade.insights.title")} - Next_Edu`,
+    description: t("classManagement.grade.insights.description"),
+  }
+}
+
+export default async function TeacherGradeInsightsPage({ searchParams }: { searchParams: Promise<SearchParams> }): Promise<JSX.Element> {
  await requirePermission(Permissions.GRADE_RECORD_READ)
+  const t = await getTranslations("school")
  const params = await searchParams
  const gradeId = getParam(params, "gradeId")

@@ -41,13 +46,13 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
    return (
      <div className="flex h-full flex-col space-y-8 p-8">
        <div className="space-y-1">
-          <h2 className="text-2xl font-bold tracking-tight">Grade Insights</h2>
-          <p className="text-muted-foreground">View grade-level homework statistics for grades you lead.</p>
+          <h2 className="text-2xl font-bold tracking-tight">{t("classManagement.grade.insights.title")}</h2>
+          <p className="text-muted-foreground">{t("classManagement.grade.insights.description")}</p>
        </div>
        <EmptyState
          icon={BarChart3}
-          title="No grades assigned"
-          description="You are not assigned as a grade head or teaching head for any grade."
+          title={t("classManagement.grade.insights.noGrades")}
+          description={t("classManagement.grade.insights.noGradesDescription")}
          className="h-[360px] bg-card"
        />
      </div>
@@ -57,27 +62,27 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
  return (
    <div className="flex h-full flex-col space-y-8 p-8">
      <div className="space-y-1">
-        <h2 className="text-2xl font-bold tracking-tight">Grade Insights</h2>
-        <p className="text-muted-foreground">Homework statistics aggregated across all classes in a grade.</p>
+        <h2 className="text-2xl font-bold tracking-tight">{t("classManagement.grade.insights.title")}</h2>
+        <p className="text-muted-foreground">{t("classManagement.grade.insights.description")}</p>
      </div>

      <Card className="shadow-none">
        <CardHeader className="flex flex-row items-center justify-between space-y-0">
-          <CardTitle className="text-base">Filters</CardTitle>
+          <CardTitle className="text-base">{t("classManagement.grade.insights.filters")}</CardTitle>
          <Badge variant="secondary" className="tabular-nums">
            {grades.length}
          </Badge>
        </CardHeader>
        <CardContent>
          <form action="/management/grade/insights" method="get" className="flex flex-col gap-3 md:flex-row md:items-center">
-            <label htmlFor="gradeId" className="text-sm font-medium">Grade</label>
+            <label htmlFor="gradeId" className="text-sm font-medium">{t("classManagement.grade.insights.grade")}</label>
            <select
              id="gradeId"
              name="gradeId"
              defaultValue={selected || "all"}
              className="h-10 w-full rounded-md border bg-background px-3 text-sm md:w-[360px]"
            >
-              <option value="all">Select a grade</option>
+              <option value="all">{t("classManagement.grade.insights.selectGrade")}</option>
              {grades.map((g) => (
                <option key={g.id} value={g.id}>
                  {g.school.name} / {g.name}
@@ -85,7 +90,7 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
              ))}
            </select>
            <Button type="submit" className="md:ml-2">
-              Apply
+              {t("classManagement.grade.insights.apply")}
            </Button>
          </form>
        </CardContent>
@@ -94,47 +99,47 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
      {!selected ? (
        <EmptyState
          icon={BarChart3}
-          title="Select a grade to view insights"
-          description="Pick a grade to see latest homework and historical score statistics."
+          title={t("classManagement.grade.insights.selectToView")}
+          description={t("classManagement.grade.insights.selectToViewDescription")}
          className="h-[360px] bg-card"
        />
      ) : !insights ? (
        <EmptyState
          icon={BarChart3}
-          title="Grade not found"
-          description="This grade may not exist or has no accessible data."
+          title={t("classManagement.grade.insights.notFound")}
+          description={t("classManagement.grade.insights.notFoundDescription")}
          className="h-[360px] bg-card"
        />
      ) : insights.assignments.length === 0 ? (
        <EmptyState
          icon={BarChart3}
-          title="No homework data for this grade"
-          description="No homework assignments were targeted to students in this grade yet."
+          title={t("classManagement.grade.insights.noData")}
+          description={t("classManagement.grade.insights.noDataDescription")}
          className="h-[360px] bg-card"
        />
      ) : (
        <div className="space-y-6">
          <div className="grid gap-4 md:grid-cols-4">
            <StatCard
-              title="Classes"
+              title={t("classManagement.grade.insights.classes")}
              value={insights.classCount}
              description={`${insights.grade.school.name} / ${insights.grade.name}`}
              valueClassName="tabular-nums"
            />
            <StatCard
-              title="Students"
+              title={t("classManagement.grade.insights.students")}
              value={insights.studentCounts.total}
-              description={`Active ${insights.studentCounts.active} • Inactive ${insights.studentCounts.inactive}`}
+              description={`${t("classManagement.grade.insights.active")} ${insights.studentCounts.active} • ${t("classManagement.grade.insights.inactive")} ${insights.studentCounts.inactive}`}
              valueClassName="tabular-nums"
            />
            <StatCard
-              title="Overall Avg"
+              title={t("classManagement.grade.insights.overallAvg")}
              value={formatScore(insights.overallScores.avg)}
-              description="Across graded homework"
+              description="-"
              valueClassName="tabular-nums"
            />
            <StatCard
-              title="Latest Avg"
+              title={t("classManagement.grade.insights.latestAvg")}
              value={formatScore(insights.latest?.scoreStats.avg ?? null)}
              description={insights.latest ? insights.latest.title : "-"}
              valueClassName="tabular-nums"
@@ -143,7 +148,7 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc

          <Card className="shadow-none">
            <CardHeader className="flex flex-row items-center justify-between space-y-0">
-              <CardTitle className="text-base">Homework timeline</CardTitle>
+              <CardTitle className="text-base">{t("classManagement.grade.insights.homeworkTimeline")}</CardTitle>
              <Badge variant="secondary" className="tabular-nums">
                {insights.assignments.length}
              </Badge>
@@ -153,14 +158,14 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
                <Table>
                  <TableHeader>
                    <TableRow className="bg-muted/50">
-                      <TableHead>Assignment</TableHead>
-                      <TableHead>Status</TableHead>
-                      <TableHead>Created</TableHead>
-                      <TableHead className="text-right">Targeted</TableHead>
-                      <TableHead className="text-right">Submitted</TableHead>
-                      <TableHead className="text-right">Graded</TableHead>
-                      <TableHead className="text-right">Avg</TableHead>
-                      <TableHead className="text-right">Median</TableHead>
+                      <TableHead>{t("classManagement.grade.insights.assignment")}</TableHead>
+                      <TableHead>{t("classManagement.grade.insights.status")}</TableHead>
+                      <TableHead>{t("classManagement.grade.insights.created")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.targeted")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.submitted")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.graded")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.avg")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.median")}</TableHead>
                    </TableRow>
                  </TableHeader>
                  <TableBody>
@@ -188,7 +193,7 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc

          <Card className="shadow-none">
            <CardHeader className="flex flex-row items-center justify-between space-y-0">
-              <CardTitle className="text-base">Class ranking</CardTitle>
+              <CardTitle className="text-base">{t("classManagement.grade.insights.classRanking")}</CardTitle>
              <Badge variant="secondary" className="tabular-nums">
                {insights.classes.length}
              </Badge>
@@ -198,12 +203,12 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
                <Table>
                  <TableHeader>
                    <TableRow className="bg-muted/50">
-                      <TableHead>Class</TableHead>
-                      <TableHead className="text-right">Students</TableHead>
-                      <TableHead className="text-right">Latest Avg</TableHead>
-                      <TableHead className="text-right">Prev Avg</TableHead>
-                      <TableHead className="text-right">Δ</TableHead>
-                      <TableHead className="text-right">Overall Avg</TableHead>
+                      <TableHead>{t("classManagement.grade.insights.class")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.students")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.latestAvgCol")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.prevAvg")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.delta")}</TableHead>
+                      <TableHead className="text-right">{t("classManagement.grade.insights.overallAvgCol")}</TableHead>
                    </TableRow>
                  </TableHeader>
                  <TableBody>
@@ -230,4 +235,3 @@ export default async function TeacherGradeInsightsPage({ searchParams }: { searc
    </div>
  )
 }
-
--- a/src/app/(dashboard)/parent/diagnostic/error.tsx
+++ b/src/app/(dashboard)/parent/diagnostic/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function ParentDiagnosticError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="子女学情诊断加载失败"
+        description="抱歉，加载子女诊断数据时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/parent/diagnostic/loading.tsx
+++ b/src/app/(dashboard)/parent/diagnostic/loading.tsx
@@ -0,0 +1,32 @@
+import { Card, CardContent, CardHeader, CardTitle } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-8 p-6 md:p-8">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-48" />
+        <Skeleton className="h-4 w-64" />
+      </div>
+      <div className="space-y-8">
+        {Array.from({ length: 2 }).map((_, i) => (
+          <Card key={i}>
+            <CardHeader>
+              <CardTitle className="text-lg">
+                <Skeleton className="h-5 w-32" />
+              </CardTitle>
+            </CardHeader>
+            <CardContent className="space-y-4">
+              <Skeleton className="h-72 w-full" />
+              <div className="grid gap-4 md:grid-cols-2">
+                {Array.from({ length: 2 }).map((_, j) => (
+                  <Skeleton key={j} className="h-40 w-full" />
+                ))}
+              </div>
+            </CardContent>
+          </Card>
+        ))}
+      </div>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/parent/diagnostic/page.tsx
+++ b/src/app/(dashboard)/parent/diagnostic/page.tsx
@@ -0,0 +1,70 @@
+import { Stethoscope } from "lucide-react"
+
+import { requirePermission } from "@/shared/lib/auth-guard"
+import { Permissions } from "@/shared/types/permissions"
+import { getStudentMasterySummary } from "@/modules/diagnostic/data-access"
+import { getDiagnosticReports } from "@/modules/diagnostic/data-access-reports"
+import { StudentDiagnosticView } from "@/modules/diagnostic/components/student-diagnostic-view"
+import {
+  ParentChildrenDataPage,
+  ParentNoChildrenPage,
+} from "@/modules/parent/components/parent-children-data-page"
+
+export const dynamic = "force-dynamic"
+
+export default async function ParentDiagnosticPage() {
+  const ctx = await requirePermission(Permissions.DIAGNOSTIC_READ)
+
+  if (ctx.dataScope.type !== "children" || ctx.dataScope.childrenIds.length === 0) {
+    return (
+      <ParentNoChildrenPage
+        title="Children Diagnostic"
+        description="View your children's knowledge point mastery and diagnostic reports."
+        icon={Stethoscope}
+        emptyTitle="No children linked"
+        emptyDescription="Your account is not linked to any student accounts yet. Please contact the school administrator."
+      />
+    )
+  }
+
+  // 使用 allSettled 容错：单个子女查询失败不影响其他子女展示
+  const results = await Promise.allSettled(
+    ctx.dataScope.childrenIds.map(async (id) => {
+      const [summary, reports] = await Promise.all([
+        getStudentMasterySummary(id),
+        getDiagnosticReports({ studentId: id }),
+      ])
+      return { summary, reports, studentId: id }
+    }),
+  )
+  const validItems = results
+    .filter(
+      (r): r is PromiseFulfilledResult<{
+        summary: Awaited<ReturnType<typeof getStudentMasterySummary>>
+        reports: Awaited<ReturnType<typeof getDiagnosticReports>>
+        studentId: string
+      }> => r.status === "fulfilled",
+    )
+    .map((r) => r.value)
+
+  return (
+    <ParentChildrenDataPage
+      title="Children Diagnostic"
+      description="View knowledge point mastery and diagnostic reports for all your children."
+      icon={Stethoscope}
+      noRecordsTitle="No diagnostic data"
+      noRecordsDescription="Your children don't have any diagnostic data yet."
+      items={validItems}
+      renderItem={({ summary, reports }) => (
+        <>
+          <div className="border-b pb-2">
+            <h3 className="text-lg font-semibold">
+              {summary?.studentName ?? "Unknown student"}
+            </h3>
+          </div>
+          <StudentDiagnosticView summary={summary} reports={reports} />
+        </>
+      )}
+    />
+  )
+}
--- a/src/app/(dashboard)/student/grades/page.tsx
+++ b/src/app/(dashboard)/student/grades/page.tsx
@@ -1,26 +1,21 @@
-import { getAuthContext } from "@/shared/lib/auth-guard"
+import { requirePermission } from "@/shared/lib/auth-guard"
+import { Permissions } from "@/shared/types/permissions"
 import { getStudentGradeSummary } from "@/modules/grades/data-access"
 import { StudentGradeSummary } from "@/modules/grades/components/student-grade-summary"
 import { GradeFilters } from "@/modules/grades/components/grade-filters"
 import { GradeTrendCard } from "@/modules/grades/components/grade-trend-card"
 import { EmptyState } from "@/shared/components/ui/empty-state"
 import { UserX } from "lucide-react"
+import { getParam, type SearchParams } from "@/shared/lib/search-params"

 export const dynamic = "force-dynamic"

-type SearchParams = { [key: string]: string | string[] | undefined }
-
-const getParam = (params: SearchParams, key: string) => {
-  const v = params[key]
-  return Array.isArray(v) ? v[0] : v
-}
-
 export default async function StudentGradesPage({
  searchParams,
 }: {
  searchParams: Promise<SearchParams>
 }) {
-  const ctx = await getAuthContext()
+  const ctx = await requirePermission(Permissions.GRADE_RECORD_READ)
  const [sp, summary] = await Promise.all([
    searchParams,
    getStudentGradeSummary(ctx.userId),
--- a/src/app/(dashboard)/teacher/diagnostic/class/[classId]/error.tsx
+++ b/src/app/(dashboard)/teacher/diagnostic/class/[classId]/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function DiagnosticClassError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="班级学情诊断加载失败"
+        description="抱歉，加载班级诊断数据时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/diagnostic/class/[classId]/loading.tsx
+++ b/src/app/(dashboard)/teacher/diagnostic/class/[classId]/loading.tsx
@@ -0,0 +1,30 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <Skeleton className="h-8 w-48" />
+      <div className="grid gap-4 md:grid-cols-2">
+        <Card>
+          <CardHeader>
+            <Skeleton className="h-5 w-40" />
+          </CardHeader>
+          <CardContent>
+            <Skeleton className="h-72 w-full" />
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <Skeleton className="h-5 w-40" />
+          </CardHeader>
+          <CardContent className="space-y-2">
+            {Array.from({ length: 6 }).map((_, i) => (
+              <Skeleton key={i} className="h-8 w-full" />
+            ))}
+          </CardContent>
+        </Card>
+      </div>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/diagnostic/error.tsx
+++ b/src/app/(dashboard)/teacher/diagnostic/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function TeacherDiagnosticError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="学情诊断页面加载失败"
+        description="抱歉，页面加载时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/diagnostic/loading.tsx
+++ b/src/app/(dashboard)/teacher/diagnostic/loading.tsx
@@ -0,0 +1,23 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-48" />
+        <Skeleton className="h-4 w-64" />
+      </div>
+      <Card>
+        <CardHeader>
+          <Skeleton className="h-5 w-40" />
+        </CardHeader>
+        <CardContent className="space-y-3">
+          {Array.from({ length: 5 }).map((_, i) => (
+            <Skeleton key={i} className="h-12 w-full" />
+          ))}
+        </CardContent>
+      </Card>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/diagnostic/student/[studentId]/error.tsx
+++ b/src/app/(dashboard)/teacher/diagnostic/student/[studentId]/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function DiagnosticStudentError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="学生学情诊断加载失败"
+        description="抱歉，加载学生诊断数据时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/diagnostic/student/[studentId]/loading.tsx
+++ b/src/app/(dashboard)/teacher/diagnostic/student/[studentId]/loading.tsx
@@ -0,0 +1,30 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <Skeleton className="h-8 w-48" />
+      <div className="grid gap-4 md:grid-cols-2">
+        <Card>
+          <CardHeader>
+            <Skeleton className="h-5 w-40" />
+          </CardHeader>
+          <CardContent>
+            <Skeleton className="h-72 w-full" />
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <Skeleton className="h-5 w-40" />
+          </CardHeader>
+          <CardContent className="space-y-2">
+            {Array.from({ length: 6 }).map((_, i) => (
+              <Skeleton key={i} className="h-8 w-full" />
+            ))}
+          </CardContent>
+        </Card>
+      </div>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/analytics/error.tsx
+++ b/src/app/(dashboard)/teacher/grades/analytics/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function TeacherGradesAnalyticsError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="成绩分析加载失败"
+        description="抱歉，分析数据加载时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/analytics/loading.tsx
+++ b/src/app/(dashboard)/teacher/grades/analytics/loading.tsx
@@ -0,0 +1,31 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-48" />
+        <Skeleton className="h-4 w-64" />
+      </div>
+      <div className="grid gap-4 md:grid-cols-2">
+        <Card>
+          <CardHeader>
+            <Skeleton className="h-5 w-40" />
+          </CardHeader>
+          <CardContent>
+            <Skeleton className="h-64 w-full" />
+          </CardContent>
+        </Card>
+        <Card>
+          <CardHeader>
+            <Skeleton className="h-5 w-40" />
+          </CardHeader>
+          <CardContent>
+            <Skeleton className="h-64 w-full" />
+          </CardContent>
+        </Card>
+      </div>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/entry/error.tsx
+++ b/src/app/(dashboard)/teacher/grades/entry/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function TeacherGradesEntryError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="成绩录入页面加载失败"
+        description="抱歉，页面加载时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/entry/loading.tsx
+++ b/src/app/(dashboard)/teacher/grades/entry/loading.tsx
@@ -0,0 +1,23 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-40" />
+        <Skeleton className="h-4 w-56" />
+      </div>
+      <Card>
+        <CardHeader>
+          <Skeleton className="h-5 w-48" />
+        </CardHeader>
+        <CardContent className="space-y-3">
+          {Array.from({ length: 8 }).map((_, i) => (
+            <Skeleton key={i} className="h-12 w-full" />
+          ))}
+        </CardContent>
+      </Card>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/error.tsx
+++ b/src/app/(dashboard)/teacher/grades/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function TeacherGradesError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="成绩页面加载失败"
+        description="抱歉，页面加载时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/loading.tsx
+++ b/src/app/(dashboard)/teacher/grades/loading.tsx
@@ -0,0 +1,28 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-40" />
+        <Skeleton className="h-4 w-56" />
+      </div>
+      <div className="flex flex-wrap gap-3">
+        <Skeleton className="h-9 w-32" />
+        <Skeleton className="h-9 w-32" />
+        <Skeleton className="h-9 w-32" />
+      </div>
+      <Card>
+        <CardHeader>
+          <Skeleton className="h-5 w-48" />
+        </CardHeader>
+        <CardContent className="space-y-3">
+          {Array.from({ length: 6 }).map((_, i) => (
+            <Skeleton key={i} className="h-10 w-full" />
+          ))}
+        </CardContent>
+      </Card>
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/stats/error.tsx
+++ b/src/app/(dashboard)/teacher/grades/stats/error.tsx
@@ -0,0 +1,27 @@
+"use client"
+
+import { AlertCircle } from "lucide-react"
+
+import { EmptyState } from "@/shared/components/ui/empty-state"
+
+export default function TeacherGradesStatsError({
+  reset,
+}: {
+  error: Error & { digest?: string }
+  reset: () => void
+}) {
+  return (
+    <div className="flex h-full flex-col items-center justify-center space-y-4 p-8">
+      <EmptyState
+        icon={AlertCircle}
+        title="成绩统计加载失败"
+        description="抱歉，统计数据加载时发生了意外错误。请稍后重试。"
+        action={{
+          label: "重试",
+          onClick: () => reset(),
+        }}
+        className="border-none shadow-none h-auto"
+      />
+    </div>
+  )
+}
--- a/src/app/(dashboard)/teacher/grades/stats/loading.tsx
+++ b/src/app/(dashboard)/teacher/grades/stats/loading.tsx
@@ -0,0 +1,33 @@
+import { Card, CardContent, CardHeader } from "@/shared/components/ui/card"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+export default function Loading() {
+  return (
+    <div className="space-y-6">
+      <div className="space-y-2">
+        <Skeleton className="h-8 w-40" />
+        <Skeleton className="h-4 w-56" />
+      </div>
+      <div className="grid gap-4 md:grid-cols-3">
+        {Array.from({ length: 3 }).map((_, i) => (
+          <Card key={i}>
+            <CardHeader>
+              <Skeleton className="h-5 w-32" />
+            </CardHeader>
+            <CardContent>
+              <Skeleton className="h-8 w-20" />
+            </CardContent>
+          </Card>
+        ))}
+      </div>
+      <Card>
+        <CardHeader>
+          <Skeleton className="h-5 w-48" />
+        </CardHeader>
+        <CardContent>
+          <Skeleton className="h-64 w-full" />
+        </CardContent>
+      </Card>
+    </div>
+  )
+}
--- a/src/modules/diagnostic/components/mastery-radar-chart.tsx
+++ b/src/modules/diagnostic/components/mastery-radar-chart.tsx
@@ -35,35 +35,37 @@ export function MasteryRadarChart({ data }: MasteryRadarChartProps) {
      emptyDescription="No knowledge point mastery records found for this student."
      emptyClassName="h-60"
    >
-      <ComparisonRadarChart
-        data={chartData}
-        angleKey="shortName"
-        angleTickFontSize={11}
-        domain={[0, 100]}
-        tickCount={5}
-        showLegend={hasClassAverage}
-        heightClassName="mx-auto h-96 w-full max-w-lg"
-        gridStrokeDasharray="4 4"
-        series={[
-          {
-            dataKey: "student",
-            name: "Student",
-            color: "hsl(var(--primary))",
-            fillOpacity: 0.35,
-            strokeWidth: 2,
-            show: true,
-          },
-          {
-            dataKey: "classAverage",
-            name: "Class Avg",
-            color: "hsl(var(--chart-2))",
-            fillOpacity: 0.15,
-            strokeWidth: 2,
-            strokeDasharray: "4 4",
-            show: hasClassAverage,
-          },
-        ]}
-      />
+      <div role="img" aria-label={`知识点掌握度雷达图：${isEmpty ? "暂无数据" : `共 ${data.length} 个知识点的掌握度${hasClassAverage ? "（含班级平均对比）" : ""}`}`}>
+        <ComparisonRadarChart
+          data={chartData}
+          angleKey="shortName"
+          angleTickFontSize={11}
+          domain={[0, 100]}
+          tickCount={5}
+          showLegend={hasClassAverage}
+          heightClassName="mx-auto h-96 w-full max-w-lg"
+          gridStrokeDasharray="4 4"
+          series={[
+            {
+              dataKey: "student",
+              name: "Student",
+              color: "hsl(var(--primary))",
+              fillOpacity: 0.35,
+              strokeWidth: 2,
+              show: true,
+            },
+            {
+              dataKey: "classAverage",
+              name: "Class Avg",
+              color: "hsl(var(--chart-2))",
+              fillOpacity: 0.15,
+              strokeWidth: 2,
+              strokeDasharray: "4 4",
+              show: hasClassAverage,
+            },
+          ]}
+        />
+      </div>
    </ChartCardShell>
  )
 }
--- a/src/modules/diagnostic/components/report-list.tsx
+++ b/src/modules/diagnostic/components/report-list.tsx
@@ -157,6 +157,7 @@ export function ReportList({ reports }: ReportListProps) {
      ) : (
        <div className="rounded-md border bg-card">
          <Table>
+            <caption className="sr-only">学情诊断报告列表</caption>
            <TableHeader>
              <TableRow>
                <TableHead>Type</TableHead>
@@ -175,7 +176,7 @@ export function ReportList({ reports }: ReportListProps) {
                  <TableCell>
                    <Badge variant="outline">{typeLabels[r.reportType] ?? r.reportType}</Badge>
                  </TableCell>
-                  <TableCell className="font-medium">{r.studentName}</TableCell>
+                  <TableCell className="font-medium">{r.studentName ?? (r.reportType === "class" ? "（班级报告）" : r.reportType === "grade" ? "（年级报告）" : "-")}</TableCell>
                  <TableCell>{r.period ?? "-"}</TableCell>
                  <TableCell className="text-right font-mono">
                    {r.overallScore !== null ? `${r.overallScore.toFixed(1)}%` : "-"}
@@ -195,6 +196,7 @@ export function ReportList({ reports }: ReportListProps) {
                            className="h-8 w-8 text-green-600"
                            onClick={() => setPublishId(r.id)}
                            title="Publish"
+                            aria-label={`发布报告 ${r.studentName}`}
                          >
                            <Send className="h-4 w-4" />
                          </Button>
@@ -205,6 +207,7 @@ export function ReportList({ reports }: ReportListProps) {
                          className="h-8 w-8 text-destructive"
                          onClick={() => setDeleteId(r.id)}
                          title="Delete"
+                          aria-label={`删除报告 ${r.studentName}`}
                        >
                          <Trash2 className="h-4 w-4" />
                        </Button>
--- a/src/modules/diagnostic/components/student-diagnostic-view.tsx
+++ b/src/modules/diagnostic/components/student-diagnostic-view.tsx
@@ -96,7 +96,7 @@ export function StudentDiagnosticView({ summary, reports, classAverageMastery }:
            {summary.strengths.length === 0 ? (
              <p className="text-sm text-muted-foreground">No strengths identified yet.</p>
            ) : (
-              <ul className="space-y-2">
+              <ul className="space-y-2" role="list" aria-label="优势知识点列表">
                {summary.strengths.map((m) => (
                  <li key={m.knowledgePointId} className="flex items-center justify-between">
                    <span className="text-sm">{m.knowledgePointName}</span>
@@ -119,7 +119,7 @@ export function StudentDiagnosticView({ summary, reports, classAverageMastery }:
            {summary.weaknesses.length === 0 ? (
              <p className="text-sm text-muted-foreground">No weaknesses identified.</p>
            ) : (
-              <ul className="space-y-2">
+              <ul className="space-y-2" role="list" aria-label="薄弱知识点列表">
                {summary.weaknesses.map((m) => (
                  <li key={m.knowledgePointId} className="flex items-center justify-between gap-2">
                    <div className="flex items-center gap-2 min-w-0">
@@ -162,7 +162,7 @@ export function StudentDiagnosticView({ summary, reports, classAverageMastery }:
            {latestReport.recommendations && latestReport.recommendations.length > 0 ? (
              <div>
                <h4 className="mb-2 text-sm font-semibold">Recommendations</h4>
-                <ul className="space-y-1.5">
+                <ul className="space-y-1.5" role="list" aria-label="学习建议列表">
                  {latestReport.recommendations.map((rec, i) => (
                    <li key={i} className="text-sm text-muted-foreground">• {rec}</li>
                  ))}
--- a/src/modules/diagnostic/data-access-reports.ts
+++ b/src/modules/diagnostic/data-access-reports.ts
@@ -109,7 +109,7 @@ export async function generateClassDiagnosticReport(
  const id = createId()
  await db.insert(learningDiagnosticReports).values({
    id,
-    studentId: generatedBy, // 班级报告 studentId 存生成者 ID（schema 要求 NOT NULL）
+    studentId: null, // 班级报告无单个学生，studentId 置空（P2-3 修复：不再存生成者 ID）
    generatedBy,
    reportType: "class",
    period,
@@ -141,14 +141,16 @@ export const getDiagnosticReports = cache(
    // 收集所有需要查询姓名的用户 ID（学生 + 生成者），通过 users data-access 统一获取
    const userIds = new Set<string>()
    for (const r of rows) {
-      userIds.add(r.report.studentId)
+      if (r.report.studentId) userIds.add(r.report.studentId)
      if (r.report.generatedBy) userIds.add(r.report.generatedBy)
    }
    const userMap = await getUserNamesByIds(Array.from(userIds))

    return rows.map((r) => ({
      ...serializeReport(r.report),
-      studentName: userMap.get(r.report.studentId)?.name ?? "Unknown",
+      studentName: r.report.studentId
+        ? userMap.get(r.report.studentId)?.name ?? "Unknown"
+        : null,
      generatedByName: r.report.generatedBy
        ? userMap.get(r.report.generatedBy)?.name ?? "Unknown"
        : null,
@@ -167,13 +169,16 @@ export const getDiagnosticReportById = cache(
    if (!row) return null

    // 通过 users data-access 获取学生姓名和生成者姓名
-    const userIds = [row.report.studentId]
+    const userIds: string[] = []
+    if (row.report.studentId) userIds.push(row.report.studentId)
    if (row.report.generatedBy) userIds.push(row.report.generatedBy)
    const userMap = await getUserNamesByIds(userIds)

    return {
      ...serializeReport(row.report),
-      studentName: userMap.get(row.report.studentId)?.name ?? "Unknown",
+      studentName: row.report.studentId
+        ? userMap.get(row.report.studentId)?.name ?? "Unknown"
+        : null,
      generatedByName: row.report.generatedBy
        ? userMap.get(row.report.generatedBy)?.name ?? null
        : null,
--- a/src/modules/diagnostic/types.ts
+++ b/src/modules/diagnostic/types.ts
@@ -36,7 +36,7 @@ export interface StudentMasterySummary {
 /** 诊断报告 */
 export interface DiagnosticReport {
  id: string
-  studentId: string
+  studentId: string | null
  generatedBy: string | null
  reportType: DiagnosticReportType
  period: string | null
@@ -52,7 +52,7 @@ export interface DiagnosticReport {

 /** 含学生名的诊断报告（join users 后） */
 export interface DiagnosticReportWithDetails extends DiagnosticReport {
-  studentName: string
+  studentName: string | null
  generatedByName: string | null
 }

--- a/src/modules/grades/components/class-comparison-chart.tsx
+++ b/src/modules/grades/components/class-comparison-chart.tsx
@@ -38,23 +38,25 @@ export function ClassComparisonChart({ data }: ClassComparisonChartProps) {
      emptyDescription="Select a grade and subject to compare classes."
      emptyClassName="h-60"
    >
-      <SimpleBarChart
-        data={chartData}
-        bars={[
-          { dataKey: "averageScore", name: "Average (%)", color: "hsl(var(--primary))" },
-          { dataKey: "passRate", name: "Pass Rate (%)", color: "hsl(var(--chart-2))" },
-          { dataKey: "excellentRate", name: "Excellent (%)", color: "hsl(var(--chart-3))" },
-        ]}
-        xKey="name"
-        xTruncateLength={8}
-        yDomain={[0, 100]}
-        yTickFormatter={(value: number) => `${value}%`}
-        yWidth={36}
-        heightClassName="h-[300px]"
-        margin={{ left: 8, right: 8, top: 8, bottom: 8 }}
-        showLegend
-        tooltipClassName="w-[240px]"
-      />
+      <div role="img" aria-label={`班级对比柱状图：${isEmpty ? "暂无数据" : `共 ${data.length} 个班级的均分、及格率与优秀率对比`}`}>
+        <SimpleBarChart
+          data={chartData}
+          bars={[
+            { dataKey: "averageScore", name: "Average (%)", color: "hsl(var(--primary))" },
+            { dataKey: "passRate", name: "Pass Rate (%)", color: "hsl(var(--chart-2))" },
+            { dataKey: "excellentRate", name: "Excellent (%)", color: "hsl(var(--chart-3))" },
+          ]}
+          xKey="name"
+          xTruncateLength={8}
+          yDomain={[0, 100]}
+          yTickFormatter={(value: number) => `${value}%`}
+          yWidth={36}
+          heightClassName="h-[300px]"
+          margin={{ left: 8, right: 8, top: 8, bottom: 8 }}
+          showLegend
+          tooltipClassName="w-[240px]"
+        />
+      </div>
    </ChartCardShell>
  )
 }
--- a/src/modules/grades/components/grade-distribution-chart.tsx
+++ b/src/modules/grades/components/grade-distribution-chart.tsx
@@ -70,37 +70,39 @@ export function GradeDistributionChart({ data }: GradeDistributionChartProps) {
      emptyDescription="Select a class and subject to view score distribution."
      emptyClassName="h-60"
    >
-      <SimpleBarChart
-        data={chartData}
-        bars={[
-          {
-            dataKey: "count",
-            name: "Students",
-            color: "hsl(var(--primary))",
-          },
-        ]}
-        xKey="label"
-        xTickFormatter={null}
-        yAllowDecimals={false}
-        yWidth={32}
-        heightClassName="h-[280px]"
-        margin={{ left: 8, right: 8, top: 8, bottom: 8 }}
-        tooltipClassName="w-[200px]"
-        cellColors={BUCKET_COLORS}
-        tooltipFormatter={(payload: unknown) => {
-          if (!isDistributionTooltipPayload(payload)) return null
-          const item = payload.payload
-          if (!item) return null
-          return (
-            <div className="flex w-full flex-col gap-0.5">
-              <span className="text-sm font-medium">
-                {item.label}: {item.count} student{item.count === 1 ? "" : "s"}
-              </span>
-              <span className="text-xs text-muted-foreground">{item.percentage}% of total</span>
-            </div>
-          )
-        }}
-      />
+      <div role="img" aria-label={`分数分布柱状图：${isEmpty ? "暂无数据" : `共 ${data.totalCount} 条成绩记录分布在 5 个分数区间`}`}>
+        <SimpleBarChart
+          data={chartData}
+          bars={[
+            {
+              dataKey: "count",
+              name: "Students",
+              color: "hsl(var(--primary))",
+            },
+          ]}
+          xKey="label"
+          xTickFormatter={null}
+          yAllowDecimals={false}
+          yWidth={32}
+          heightClassName="h-[280px]"
+          margin={{ left: 8, right: 8, top: 8, bottom: 8 }}
+          tooltipClassName="w-[200px]"
+          cellColors={BUCKET_COLORS}
+          tooltipFormatter={(payload: unknown) => {
+            if (!isDistributionTooltipPayload(payload)) return null
+            const item = payload.payload
+            if (!item) return null
+            return (
+              <div className="flex w-full flex-col gap-0.5">
+                <span className="text-sm font-medium">
+                  {item.label}: {item.count} student{item.count === 1 ? "" : "s"}
+                </span>
+                <span className="text-xs text-muted-foreground">{item.percentage}% of total</span>
+              </div>
+            )
+          }}
+        />
+      </div>
    </ChartCardShell>
  )
 }
--- a/src/modules/grades/components/grade-record-list.tsx
+++ b/src/modules/grades/components/grade-record-list.tsx
@@ -3,7 +3,6 @@
 import { useState } from "react"
 import { toast } from "sonner"
 import { useRouter } from "next/navigation"
-import { Badge } from "@/shared/components/ui/badge"
 import { Button } from "@/shared/components/ui/button"
 import {
  Table,
@@ -21,18 +20,13 @@ import {
  DialogHeader,
  DialogTitle,
 } from "@/shared/components/ui/dialog"
+import { StatusBadge } from "@/shared/components/ui/status-badge"
 import { formatDate } from "@/shared/lib/utils"
 import { Trash2 } from "lucide-react"

 import { deleteGradeRecordAction } from "../actions"
 import type { GradeRecordListItem } from "../types"
-
-const typeColors: Record<string, "default" | "secondary" | "destructive" | "outline"> = {
-  exam: "default",
-  quiz: "secondary",
-  homework: "outline",
-  other: "outline",
-}
+import { GRADE_TYPE_VARIANT } from "../types"

 export function GradeRecordList({ records }: { records: GradeRecordListItem[] }) {
  const router = useRouter()
@@ -65,6 +59,7 @@ export function GradeRecordList({ records }: { records: GradeRecordListItem[] })
    <>
      <div className="rounded-md border bg-card">
        <Table>
+          <caption className="sr-only">成绩记录列表</caption>
          <TableHeader>
            <TableRow>
              <TableHead>Student</TableHead>
@@ -90,9 +85,7 @@ export function GradeRecordList({ records }: { records: GradeRecordListItem[] })
                  {r.score} / {r.fullScore}
                </TableCell>
                <TableCell>
-                  <Badge variant={typeColors[r.type]} className="capitalize">
-                    {r.type}
-                  </Badge>
+                  <StatusBadge status={r.type} variantMap={GRADE_TYPE_VARIANT} />
                </TableCell>
                <TableCell>S{r.semester}</TableCell>
                <TableCell className="text-muted-foreground">{r.recorderName}</TableCell>
@@ -103,6 +96,7 @@ export function GradeRecordList({ records }: { records: GradeRecordListItem[] })
                    size="icon"
                    className="h-8 w-8 text-destructive"
                    onClick={() => setDeleteId(r.id)}
+                    aria-label={`删除 ${r.studentName} 的 ${r.subjectName} 成绩记录`}
                  >
                    <Trash2 className="h-4 w-4" />
                  </Button>
--- a/src/modules/grades/components/grade-trend-chart.tsx
+++ b/src/modules/grades/components/grade-trend-chart.tsx
@@ -40,22 +40,24 @@ export function GradeTrendChart({ data }: GradeTrendChartProps) {
      emptyDescription="Select a class and subject to view the grade trend."
      emptyClassName="h-60"
    >
-      <TrendLineChart
-        data={chartData}
-        series={[
-          {
-            dataKey: "normalizedScore",
-            name: "Score (%)",
-            color: "hsl(var(--primary))",
-            dotRadius: 3,
-            activeDotRadius: 5,
-          },
-        ]}
-        heightClassName="h-[280px]"
-        margin={{ left: 8, right: 8, top: 8, bottom: 8 }}
-        yWidth={36}
-        tooltipClassName="w-[220px]"
-      />
+      <div role="img" aria-label={`成绩趋势图：${isEmpty ? "暂无数据" : `${data.label}，平均 ${data.averageScore.toFixed(1)}%`}`}>
+        <TrendLineChart
+          data={chartData}
+          series={[
+            {
+              dataKey: "normalizedScore",
+              name: "Score (%)",
+              color: "hsl(var(--primary))",
+              dotRadius: 3,
+              activeDotRadius: 5,
+            },
+          ]}
+          heightClassName="h-[280px]"
+          margin={{ left: 8, right: 8, top: 8, bottom: 8 }}
+          yWidth={36}
+          tooltipClassName="w-[220px]"
+        />
+      </div>
    </ChartCardShell>
  )
 }
--- a/src/modules/grades/components/subject-comparison-chart.tsx
+++ b/src/modules/grades/components/subject-comparison-chart.tsx
@@ -37,28 +37,30 @@ export function SubjectComparisonChart({ data }: SubjectComparisonChartProps) {
      emptyDescription="Select a class to compare subject performance."
      emptyClassName="h-60"
    >
-      <ComparisonRadarChart
-        data={chartData}
-        angleKey="subject"
-        angleTickFormatter={(value: string) =>
-          value.length > 6 ? `${value.slice(0, 6)}...` : value
-        }
-        heightClassName="h-[300px]"
-        series={[
-          {
-            dataKey: "averageScore",
-            name: "Average",
-            color: "hsl(var(--primary))",
-            fillOpacity: 0.4,
-          },
-          {
-            dataKey: "passRate",
-            name: "Pass Rate",
-            color: "hsl(var(--chart-2))",
-            fillOpacity: 0.2,
-          },
-        ]}
-      />
+      <div role="img" aria-label={`科目对比雷达图：${isEmpty ? "暂无数据" : `共 ${data.length} 个科目的均分与及格率对比`}`}>
+        <ComparisonRadarChart
+          data={chartData}
+          angleKey="subject"
+          angleTickFormatter={(value: string) =>
+            value.length > 6 ? `${value.slice(0, 6)}...` : value
+          }
+          heightClassName="h-[300px]"
+          series={[
+            {
+              dataKey: "averageScore",
+              name: "Average",
+              color: "hsl(var(--primary))",
+              fillOpacity: 0.4,
+            },
+            {
+              dataKey: "passRate",
+              name: "Pass Rate",
+              color: "hsl(var(--chart-2))",
+              fillOpacity: 0.2,
+            },
+          ]}
+        />
+      </div>
    </ChartCardShell>
  )
 }
--- a/src/modules/grades/components/widget-boundary.tsx
+++ b/src/modules/grades/components/widget-boundary.tsx
@@ -0,0 +1,139 @@
+"use client"
+
+/**
+ * Grades/Diagnostic 模块通用 Widget 边界组件。
+ *
+ * 组合三个能力：
+ * 1. Error Boundary — 隔离故障域，单个 Widget 抛错不影响其他区块
+ * 2. Suspense — 流式渲染时显示骨架屏，避免白屏等待
+ * 3. Skeleton — 与 Widget 尺寸匹配的占位
+ *
+ * 用法：
+ * ```tsx
+ * <WidgetBoundary title="成绩趋势">
+ *   <GradeTrendChart data={data} />
+ * </WidgetBoundary>
+ * ```
+ */
+
+import { Component, Suspense, type ReactNode } from "react"
+import { AlertCircle } from "lucide-react"
+import { Button } from "@/shared/components/ui/button"
+import { Skeleton } from "@/shared/components/ui/skeleton"
+
+interface WidgetBoundaryProps {
+  children: ReactNode
+  /** Widget 标题（用于错误提示和 aria-label） */
+  title?: string
+  /** 骨架屏高度（默认 200px） */
+  skeletonHeight?: number
+  /** 自定义错误描述 */
+  fallbackDescription?: string
+  /** 重试按钮文案 */
+  retryLabel?: string
+}
+
+interface WidgetBoundaryState {
+  hasError: boolean
+}
+
+class WidgetErrorBoundary extends Component<
+  Pick<
+    WidgetBoundaryProps,
+    "title" | "fallbackDescription" | "retryLabel" | "children"
+  >,
+  WidgetBoundaryState
+> {
+  constructor(props: WidgetBoundaryProps) {
+    super(props)
+    this.state = { hasError: false }
+  }
+
+  static getDerivedStateFromError(): WidgetBoundaryState {
+    return { hasError: true }
+  }
+
+  handleReset = (): void => {
+    this.setState({ hasError: false })
+  }
+
+  render(): ReactNode {
+    if (this.state.hasError) {
+      const title = this.props.title ?? "区块"
+      return (
+        <div
+          role="alert"
+          aria-live="assertive"
+          className="flex h-full min-h-[200px] flex-col items-center justify-center gap-3 rounded-lg border border-destructive/30 bg-destructive/5 p-6 text-center"
+        >
+          <AlertCircle className="h-8 w-8 text-destructive" aria-hidden="true" />
+          <div className="space-y-1">
+            <p className="text-sm font-medium text-foreground">
+              {title}加载失败
+            </p>
+            <p className="text-xs text-muted-foreground">
+              {this.props.fallbackDescription ?? "请重试或刷新页面"}
+            </p>
+          </div>
+          <Button
+            size="sm"
+            variant="outline"
+            onClick={this.handleReset}
+            aria-label={`重试加载${title}`}
+          >
+            {this.props.retryLabel ?? "重试"}
+          </Button>
+        </div>
+      )
+    }
+
+    return this.props.children
+  }
+}
+
+function WidgetSkeleton({
+  height,
+  title,
+}: {
+  height: number
+  title?: string
+}): ReactNode {
+  return (
+    <div
+      role="status"
+      aria-label={`${title ?? "区块"}加载中`}
+      aria-live="polite"
+      className="space-y-3 p-4"
+      style={{ minHeight: height }}
+    >
+      <Skeleton className="h-6 w-1/3" />
+      <Skeleton className="h-4 w-full" />
+      <Skeleton className="h-4 w-2/3" />
+      <Skeleton className="h-32 w-full" />
+    </div>
+  )
+}
+
+export function WidgetBoundary({
+  children,
+  title,
+  skeletonHeight = 200,
+  fallbackDescription,
+  retryLabel,
+}: WidgetBoundaryProps): ReactNode {
+  return (
+    <WidgetErrorBoundary
+      title={title}
+      fallbackDescription={fallbackDescription}
+      retryLabel={retryLabel}
+    >
+      <Suspense
+        fallback={
+          <WidgetSkeleton height={skeletonHeight} title={title} />
+        }
+      >
+        {children}
+      </Suspense>
+    </WidgetErrorBoundary>
+  )
+}
--- a/src/modules/grades/data-access-analytics.ts
+++ b/src/modules/grades/data-access-analytics.ts
@@ -13,11 +13,16 @@ import { getSubjectOptions } from "@/modules/school/data-access"
 import type { DataScope } from "@/shared/types/permissions"

 import { buildScopeClassFilter, normalize, toNumber } from "./lib/grade-utils"
+import {
+  buildGradeTrendPoints,
+  computeClassComparisonStats,
+  computeGradeDistribution,
+  computeSubjectComparisonStats,
+  computeTrendAverage,
+} from "./stats-service"
 import type {
  ClassComparisonItem,
-  GradeDistributionBucket,
  GradeDistributionResult,
-  GradeTrendPoint,
  GradeTrendResult,
  SubjectComparisonItem,
 } from "./types"
@@ -64,20 +69,8 @@ export const getGradeTrend = cache(
      subjectName = subject?.name ?? "Unknown"
    }

-    const points: GradeTrendPoint[] = rows.map((r) => {
-      const score = toNumber(r.record.score)
-      const fullScore = toNumber(r.record.fullScore)
-      return {
-        date: r.record.createdAt.toISOString(),
-        title: r.record.title,
-        score,
-        fullScore,
-        normalizedScore: normalize(score, fullScore),
-        type: r.record.type,
-      }
-    })
-
-    const avg = points.reduce((acc, p) => acc + p.normalizedScore, 0) / points.length
+    const points = buildGradeTrendPoints(rows)
+    const avg = computeTrendAverage(points)
    const finalClassName = className ?? "Class"
    const studentLabel = params.studentId
      ? `Student ${params.studentId.slice(-4)}`
@@ -88,7 +81,7 @@ export const getGradeTrend = cache(
        ? `${finalClassName} · ${subjectName} · ${studentLabel}`
        : `${finalClassName} · ${studentLabel}`,
      points,
-      averageScore: Math.round(avg * 100) / 100,
+      averageScore: avg,
    }
  }
 )
@@ -145,46 +138,11 @@ export const getClassComparison = cache(

    const result: ClassComparisonItem[] = allowedClassRows.map((cls) => {
      const rows = byClass.get(cls.id) ?? []
-      if (rows.length === 0) {
-        return {
-          classId: cls.id,
-          className: cls.name,
-          averageScore: 0,
-          medianScore: 0,
-          passRate: 0,
-          excellentRate: 0,
-          count: 0,
-          studentCount: 0,
-        }
-      }
-
-      const normalized = rows.map((r) =>
-        normalize(toNumber(r.score), toNumber(r.fullScore))
-      )
-      const sorted = [...normalized].sort((a, b) => a - b)
-      const mid = Math.floor(sorted.length / 2)
-      const median =
-        sorted.length % 2 === 0 ? (sorted[mid - 1] + sorted[mid]) / 2 : sorted[mid]
-      const avg = normalized.reduce((a, b) => a + b, 0) / normalized.length
-      const uniqueStudents = new Set(rows.map((r) => r.studentId)).size
-
-      const { passCount, excellentCount } = normalized.reduce(
-        (acc, s) => ({
-          passCount: acc.passCount + (s >= 60 ? 1 : 0),
-          excellentCount: acc.excellentCount + (s >= 85 ? 1 : 0),
-        }),
-        { passCount: 0, excellentCount: 0 }
-      )
-
+      const stats = computeClassComparisonStats(rows)
      return {
        classId: cls.id,
        className: cls.name,
-        averageScore: Math.round(avg * 100) / 100,
-        medianScore: Math.round(median * 100) / 100,
-        passRate: Math.round((passCount / normalized.length) * 10000) / 100,
-        excellentRate: Math.round((excellentCount / normalized.length) * 10000) / 100,
-        count: normalized.length,
-        studentCount: uniqueStudents,
+        ...stats,
      }
    })

@@ -234,28 +192,11 @@ export const getSubjectComparison = cache(
    const result: SubjectComparisonItem[] = []
    for (const [subjectId, entry] of bySubject.entries()) {
      if (entry.scores.length === 0) continue
-      const sorted = [...entry.scores].sort((a, b) => a - b)
-      const mid = Math.floor(sorted.length / 2)
-      const median =
-        sorted.length % 2 === 0 ? (sorted[mid - 1] + sorted[mid]) / 2 : sorted[mid]
-      const avg = entry.scores.reduce((a, b) => a + b, 0) / entry.scores.length
-
-      const { passCount, excellentCount } = entry.scores.reduce(
-        (acc, s) => ({
-          passCount: acc.passCount + (s >= 60 ? 1 : 0),
-          excellentCount: acc.excellentCount + (s >= 85 ? 1 : 0),
-        }),
-        { passCount: 0, excellentCount: 0 }
-      )
-
+      const stats = computeSubjectComparisonStats(entry.scores)
      result.push({
        subjectId,
        subjectName: entry.name,
-        averageScore: Math.round(avg * 100) / 100,
-        medianScore: Math.round(median * 100) / 100,
-        passRate: Math.round((passCount / entry.scores.length) * 10000) / 100,
-        excellentRate: Math.round((excellentCount / entry.scores.length) * 10000) / 100,
-        count: entry.scores.length,
+        ...stats,
      })
    }

@@ -289,24 +230,6 @@ export const getGradeDistribution = cache(
      .from(gradeRecords)
      .where(and(...conditions))

-    const buckets: GradeDistributionBucket[] = [
-      { label: "90-100", min: 90, max: 100, count: 0 },
-      { label: "80-89", min: 80, max: 89, count: 0 },
-      { label: "70-79", min: 70, max: 79, count: 0 },
-      { label: "60-69", min: 60, max: 69, count: 0 },
-      { label: "<60", min: 0, max: 59, count: 0 },
-    ]
-
-    for (const r of rows) {
-      const normalized = normalize(toNumber(r.score), toNumber(r.fullScore))
-      const rounded = Math.round(normalized)
-      if (rounded >= 90) buckets[0].count++
-      else if (rounded >= 80) buckets[1].count++
-      else if (rounded >= 70) buckets[2].count++
-      else if (rounded >= 60) buckets[3].count++
-      else buckets[4].count++
-    }
-
-    return { buckets, totalCount: rows.length }
+    return computeGradeDistribution(rows)
  }
 )
--- a/src/modules/grades/data-access-ranking.ts
+++ b/src/modules/grades/data-access-ranking.ts
@@ -9,8 +9,8 @@ import { getStudentActiveClassId } from "@/modules/classes/data-access"
 import { getUserNamesByIds } from "@/modules/users/data-access"

 import { normalize, toNumber } from "./lib/grade-utils"
+import { buildRankingTrendPoints, type RankingTrendEntry } from "./stats-service"
 import type {
-  RankingTrendPoint,
  RankingTrendResult,
 } from "./types"

@@ -56,13 +56,7 @@ export const getRankingTrend = cache(
      .where(and(...conditions))
      .orderBy(asc(gradeRecords.createdAt))

-    const byTitle = new Map<
-      string,
-      {
-        date: Date
-        entries: Array<{ studentId: string; normalized: number }>
-      }
-    >()
+    const byTitle = new Map<string, RankingTrendEntry>()

    for (const r of rows) {
      const entry = byTitle.get(r.title) ?? { date: r.createdAt, entries: [] }
@@ -73,33 +67,7 @@ export const getRankingTrend = cache(
      byTitle.set(r.title, entry)
    }

-    const points: RankingTrendPoint[] = []
-    for (const [title, entry] of byTitle.entries()) {
-      if (entry.entries.length === 0) continue
-      const sorted = [...entry.entries].sort((a, b) => b.normalized - a.normalized)
-      // Single traversal: find rank and student entry together
-      let rank = 0
-      let studentEntry: { studentId: string; normalized: number } | null = null
-      for (let i = 0; i < sorted.length; i += 1) {
-        const e = sorted[i]
-        if (e.studentId === studentId) {
-          rank = i + 1
-          studentEntry = e
-          break
-        }
-      }
-      if (rank <= 0 || !studentEntry) continue
-
-      points.push({
-        title,
-        date: entry.date.toISOString(),
-        score: studentEntry.normalized,
-        rank,
-        totalStudents: sorted.length,
-      })
-    }
-
-    points.sort((a, b) => new Date(a.date).getTime() - new Date(b.date).getTime())
+    const points = buildRankingTrendPoints(byTitle, studentId)

    return {
      studentId,
--- a/src/modules/grades/data-access.ts
+++ b/src/modules/grades/data-access.ts
@@ -17,6 +17,7 @@ import { getUserNamesByIds } from "@/modules/users/data-access"
 import type { DataScope } from "@/shared/types/permissions"

 import { buildScopeClassFilter, toNumber } from "./lib/grade-utils"
+import { computeAverageScore, computeGradeStats } from "./stats-service"
 import type {
  ClassGradeStats,
  ClassRankingItem,
@@ -208,40 +209,7 @@ export const getClassGradeStats = cache(
      .from(gradeRecords)
      .where(and(...conditions))

-    if (rows.length === 0) return null
-
-    const scores = rows.map((r) => toNumber(r.score))
-    const fullScores = rows.map((r) => toNumber(r.fullScore))
-    const countN = scores.length
-    const sum = scores.reduce((a, b) => a + b, 0)
-    const average = sum / countN
-    const sorted = [...scores].sort((a, b) => a - b)
-    const mid = Math.floor(countN / 2)
-    const median = countN % 2 === 0 ? (sorted[mid - 1] + sorted[mid]) / 2 : sorted[mid]
-    const max = sorted[countN - 1]
-    const min = sorted[0]
-    const variance = scores.reduce((acc, s) => acc + Math.pow(s - average, 2), 0) / countN
-    const stdDev = Math.sqrt(variance)
-
-    let passCount = 0
-    let excellentCount = 0
-    for (let i = 0; i < countN; i++) {
-      if (fullScores[i] <= 0) continue
-      const ratio = scores[i] / fullScores[i]
-      if (ratio >= 0.6) passCount++
-      if (ratio >= 0.85) excellentCount++
-    }
-
-    return {
-      average: Math.round(average * 100) / 100,
-      median: Math.round(median * 100) / 100,
-      max,
-      min,
-      stdDev: Math.round(stdDev * 100) / 100,
-      passRate: Math.round((passCount / countN) * 10000) / 100,
-      excellentRate: Math.round((excellentCount / countN) * 10000) / 100,
-      count: countN,
-    }
+    return computeGradeStats(rows)
  }
 )

@@ -300,13 +268,13 @@ export const getStudentGradeSummary = cache(
    createdAt: r.record.createdAt.toISOString(),
  }))

-  const avg = listItems.reduce((a, b) => a + b.score, 0) / listItems.length
+  const avg = computeAverageScore(listItems.map((i) => i.score))

  return {
    studentId,
    studentName: studentName ?? "Unknown",
    records: listItems,
-    averageScore: Math.round(avg * 100) / 100,
+    averageScore: avg,
    rank: 0,
  }
  }
--- a/src/modules/grades/lib/grade-utils.ts
+++ b/src/modules/grades/lib/grade-utils.ts
@@ -2,7 +2,8 @@ import "server-only"

 import { eq, inArray, sql, type SQL } from "drizzle-orm"

-import { gradeRecords } from "@/shared/db/schema"
+import { db } from "@/shared/db"
+import { classes, gradeRecords } from "@/shared/db/schema"
 import type { DataScope } from "@/shared/types/permissions"

 /**
@@ -39,7 +40,16 @@ export const buildScopeClassFilter = (scope: DataScope): SQL | null => {
      ? inArray(gradeRecords.classId, scope.classIds)
      : sql`1=0`
  }
-  if (scope.type === "grade_managed") return sql`1=0`
+  if (scope.type === "grade_managed") {
+    // P2-4 修复：grade_managed scope 应返回所管年级的班级成绩记录
+    // 通过子查询过滤 classId IN (SELECT id FROM classes WHERE grade_id IN (...))
+    return scope.gradeIds.length > 0
+      ? inArray(
+          gradeRecords.classId,
+          db.select({ id: classes.id }).from(classes).where(inArray(classes.gradeId, scope.gradeIds))
+        )
+      : sql`1=0`
+  }
  if (scope.type === "class_members") return null
  if (scope.type === "children") {
    return scope.childrenIds.length > 0
--- a/src/modules/grades/stats-service.ts
+++ b/src/modules/grades/stats-service.ts
@@ -0,0 +1,305 @@
+/**
+ * Grade statistics pure functions.
+ *
+ * Extracted from data-access / data-access-analytics / data-access-ranking
+ * to keep data-access layer focused on DB I/O and make statistics logic
+ * independently testable. All functions are pure (no side effects, no I/O).
+ */
+
+import { normalize, toNumber } from "./lib/grade-utils"
+import type {
+  ClassComparisonItem,
+  GradeDistributionBucket,
+  GradeDistributionResult,
+  GradeStats,
+  GradeTrendPoint,
+  RankingTrendPoint,
+} from "./types"
+
+/** Round to 2 decimal places. */
+const round2 = (n: number): number => Math.round(n * 100) / 100
+
+/** Pass threshold (60% of full score, normalized to 60/100). */
+export const PASS_THRESHOLD = 60
+
+/** Excellent threshold (85% of full score, normalized to 85/100). */
+export const EXCELLENT_THRESHOLD = 85
+
+/**
+ * Raw score row from DB (numeric columns may be string | number depending on driver).
+ */
+export interface RawScoreRow {
+  score: unknown
+  fullScore: unknown
+}
+
+/**
+ * Compute aggregate stats (average/median/max/min/stdDev/passRate/excellentRate/count)
+ * from a list of raw score rows. Returns null when rows is empty.
+ */
+export function computeGradeStats(rows: RawScoreRow[]): GradeStats | null {
+  if (rows.length === 0) return null
+
+  const scores = rows.map((r) => toNumber(r.score))
+  const fullScores = rows.map((r) => toNumber(r.fullScore))
+  const countN = scores.length
+  const sum = scores.reduce((a, b) => a + b, 0)
+  const average = sum / countN
+  const sorted = [...scores].sort((a, b) => a - b)
+  const mid = Math.floor(countN / 2)
+  const median =
+    countN % 2 === 0 ? (sorted[mid - 1] + sorted[mid]) / 2 : sorted[mid]
+  const max = sorted[countN - 1]
+  const min = sorted[0]
+  const variance =
+    scores.reduce((acc, s) => acc + Math.pow(s - average, 2), 0) / countN
+  const stdDev = Math.sqrt(variance)
+
+  let passCount = 0
+  let excellentCount = 0
+  for (let i = 0; i < countN; i += 1) {
+    if (fullScores[i] <= 0) continue
+    const ratio = scores[i] / fullScores[i]
+    if (ratio >= 0.6) passCount += 1
+    if (ratio >= 0.85) excellentCount += 1
+  }
+
+  return {
+    average: round2(average),
+    median: round2(median),
+    max,
+    min,
+    stdDev: round2(stdDev),
+    passRate: round2((passCount / countN) * 100),
+    excellentRate: round2((excellentCount / countN) * 100),
+    count: countN,
+  }
+}
+
+/**
+ * Compute average score from a list of grade record list items.
+ */
+export function computeAverageScore(scores: number[]): number {
+  if (scores.length === 0) return 0
+  return round2(scores.reduce((a, b) => a + b, 0) / scores.length)
+}
+
+/**
+ * Build a grade trend point list from raw DB rows (already ordered by date asc).
+ */
+export function buildGradeTrendPoints(
+  rows: Array<{
+    record: {
+      createdAt: Date
+      title: string
+      score: unknown
+      fullScore: unknown
+      type: string
+    }
+  }>
+): GradeTrendPoint[] {
+  return rows.map((r) => {
+    const score = toNumber(r.record.score)
+    const fullScore = toNumber(r.record.fullScore)
+    return {
+      date: r.record.createdAt.toISOString(),
+      title: r.record.title,
+      score,
+      fullScore,
+      normalizedScore: normalize(score, fullScore),
+      type: r.record.type as GradeTrendPoint["type"],
+    }
+  })
+}
+
+/**
+ * Compute the average of normalized scores from a list of trend points.
+ */
+export function computeTrendAverage(points: GradeTrendPoint[]): number {
+  if (points.length === 0) return 0
+  const avg =
+    points.reduce((acc, p) => acc + p.normalizedScore, 0) / points.length
+  return round2(avg)
+}
+
+/**
+ * Compute class comparison stats for a single class from raw score rows.
+ */
+export function computeClassComparisonStats(
+  rows: Array<{
+    score: unknown
+    fullScore: unknown
+    studentId: string
+  }>
+): Pick<
+  ClassComparisonItem,
+  | "averageScore"
+  | "medianScore"
+  | "passRate"
+  | "excellentRate"
+  | "count"
+  | "studentCount"
+> {
+  if (rows.length === 0) {
+    return {
+      averageScore: 0,
+      medianScore: 0,
+      passRate: 0,
+      excellentRate: 0,
+      count: 0,
+      studentCount: 0,
+    }
+  }
+
+  const normalized = rows.map((r) =>
+    normalize(toNumber(r.score), toNumber(r.fullScore))
+  )
+  const sorted = [...normalized].sort((a, b) => a - b)
+  const mid = Math.floor(sorted.length / 2)
+  const median =
+    sorted.length % 2 === 0
+      ? (sorted[mid - 1] + sorted[mid]) / 2
+      : sorted[mid]
+  const avg = normalized.reduce((a, b) => a + b, 0) / normalized.length
+  const uniqueStudents = new Set(rows.map((r) => r.studentId)).size
+
+  let passCount = 0
+  let excellentCount = 0
+  for (const s of normalized) {
+    if (s >= PASS_THRESHOLD) passCount += 1
+    if (s >= EXCELLENT_THRESHOLD) excellentCount += 1
+  }
+
+  return {
+    averageScore: round2(avg),
+    medianScore: round2(median),
+    passRate: round2((passCount / normalized.length) * 100),
+    excellentRate: round2((excellentCount / normalized.length) * 100),
+    count: normalized.length,
+    studentCount: uniqueStudents,
+  }
+}
+
+/**
+ * Compute subject comparison stats for a single subject from normalized scores.
+ */
+export function computeSubjectComparisonStats(
+  scores: number[]
+): Pick<
+  import("./types").SubjectComparisonItem,
+  "averageScore" | "medianScore" | "passRate" | "excellentRate" | "count"
+> {
+  if (scores.length === 0) {
+    return {
+      averageScore: 0,
+      medianScore: 0,
+      passRate: 0,
+      excellentRate: 0,
+      count: 0,
+    }
+  }
+
+  const sorted = [...scores].sort((a, b) => a - b)
+  const mid = Math.floor(sorted.length / 2)
+  const median =
+    sorted.length % 2 === 0
+      ? (sorted[mid - 1] + sorted[mid]) / 2
+      : sorted[mid]
+  const avg = scores.reduce((a, b) => a + b, 0) / scores.length
+
+  let passCount = 0
+  let excellentCount = 0
+  for (const s of scores) {
+    if (s >= PASS_THRESHOLD) passCount += 1
+    if (s >= EXCELLENT_THRESHOLD) excellentCount += 1
+  }
+
+  return {
+    averageScore: round2(avg),
+    medianScore: round2(median),
+    passRate: round2((passCount / scores.length) * 100),
+    excellentRate: round2((excellentCount / scores.length) * 100),
+    count: scores.length,
+  }
+}
+
+/**
+ * Default distribution buckets (90-100, 80-89, 70-79, 60-69, <60).
+ */
+export function createDefaultBuckets(): GradeDistributionBucket[] {
+  return [
+    { label: "90-100", min: 90, max: 100, count: 0 },
+    { label: "80-89", min: 80, max: 89, count: 0 },
+    { label: "70-79", min: 70, max: 79, count: 0 },
+    { label: "60-69", min: 60, max: 69, count: 0 },
+    { label: "<60", min: 0, max: 59, count: 0 },
+  ]
+}
+
+/**
+ * Bucketize raw score rows into a grade distribution result.
+ */
+export function computeGradeDistribution(
+  rows: RawScoreRow[]
+): GradeDistributionResult {
+  const buckets = createDefaultBuckets()
+  for (const r of rows) {
+    const normalized = normalize(toNumber(r.score), toNumber(r.fullScore))
+    const rounded = Math.round(normalized)
+    if (rounded >= 90) buckets[0].count += 1
+    else if (rounded >= 80) buckets[1].count += 1
+    else if (rounded >= 70) buckets[2].count += 1
+    else if (rounded >= 60) buckets[3].count += 1
+    else buckets[4].count += 1
+  }
+  return { buckets, totalCount: rows.length }
+}
+
+/**
+ * Ranking trend entry for a single assessment (grouped by title).
+ */
+export interface RankingTrendEntry {
+  date: Date
+  entries: Array<{ studentId: string; normalized: number }>
+}
+
+/**
+ * Build ranking trend points from grouped entries.
+ * Returns points sorted by date ascending.
+ */
+export function buildRankingTrendPoints(
+  byTitle: Map<string, RankingTrendEntry>,
+  targetStudentId: string
+): RankingTrendPoint[] {
+  const points: RankingTrendPoint[] = []
+  for (const [title, entry] of byTitle.entries()) {
+    if (entry.entries.length === 0) continue
+    const sorted = [...entry.entries].sort(
+      (a, b) => b.normalized - a.normalized
+    )
+    let rank = 0
+    let studentEntry: { studentId: string; normalized: number } | null = null
+    for (let i = 0; i < sorted.length; i += 1) {
+      const e = sorted[i]
+      if (e.studentId === targetStudentId) {
+        rank = i + 1
+        studentEntry = e
+        break
+      }
+    }
+    if (rank <= 0 || !studentEntry) continue
+
+    points.push({
+      title,
+      date: entry.date.toISOString(),
+      score: studentEntry.normalized,
+      rank,
+      totalStudents: sorted.length,
+    })
+  }
+
+  points.sort(
+    (a, b) => new Date(a.date).getTime() - new Date(b.date).getTime()
+  )
+  return points
+}
--- a/src/shared/db/schema.ts
+++ b/src/shared/db/schema.ts
@@ -1247,7 +1247,7 @@ export const diagnosticReportTypeEnum = mysqlEnum("report_type", ["individual",

 export const learningDiagnosticReports = mysqlTable("learning_diagnostic_reports", {
  id: id("id").primaryKey(),
-  studentId: varchar("student_id", { length: 128 }).notNull().references(() => users.id, { onDelete: "cascade" }),
+  studentId: varchar("student_id", { length: 128 }).references(() => users.id, { onDelete: "cascade" }),
  generatedBy: varchar("generated_by", { length: 128 }).references(() => users.id, { onDelete: "set null" }),
  reportType: diagnosticReportTypeEnum.default("individual").notNull(),
  period: varchar("period", { length: 50 }),
@@ -1317,3 +1317,23 @@ export const lessonPlanTemplates = mysqlTable("lesson_plan_templates", {
 }, (table) => ({
  typeCreatorIdx: index("lpt_type_creator_idx").on(table.type, table.creatorId),
 }));
+
+// --- 25. System Settings (系统设置 - 键值对存储) ---
+
+export const systemSettings = mysqlTable("system_settings", {
+  id: id("id").primaryKey(),
+  /** 设置分组：school_info / security_policy / file_upload / notification_config */
+  category: varchar("category", { length: 50 }).notNull(),
+  /** 设置键名，如 schoolName / passwordMinLength / maxFileSize */
+  key: varchar("key", { length: 100 }).notNull(),
+  /** 设置值（JSON 字符串，支持字符串/数字/布尔/对象） */
+  value: text("value").notNull(),
+  /** 值类型：string / number / boolean / json */
+  valueType: varchar("value_type", { length: 20 }).default("string").notNull(),
+  updatedBy: varchar("updated_by", { length: 128 }),
+  createdAt: timestamp("created_at").defaultNow().notNull(),
+  updatedAt: timestamp("updated_at").defaultNow().onUpdateNow().notNull(),
+}, (table) => ({
+  categoryKeyIdx: uniqueIndex("ss_category_key_idx").on(table.category, table.key),
+  categoryIdx: index("ss_category_idx").on(table.category),
+}));