feat: 新增备课模块并修复全模块 P0/P1/P2 缺陷

主要变更:

- 新增 lesson-preparation 模块: 备课编辑器、节点编辑、AI 建议、知识点选择、版本历史、作业发布

- 新增 shared 通用组件: charts/question-bank-filters/schedule-list/ui (chip-nav/filter-bar/page-header/stat-card/stat-item)

- 新增 student/admin 端 loading.tsx 与 error.tsx, 优化加载与错误态体验

- 新增 teacher/lesson-plans 页面 (列表/新建/编辑)

- 新增 drizzle 迁移 0002_tiny_lionheart 及 snapshot

- 新增 textbooks/schema.ts 与 exams/utils/normalize-structure.ts

- 修复 Tiptap v3 SSR hydration 崩溃 (rich-text-block immediatelyRender: false)

- 重构多模块 data-access/actions/组件, 修复权限校验与类型规范

- 同步架构文档 004/005 反映新增模块、导出、依赖关系

- 归档 bugs/* 测试报告与 e2e 测试脚本 (admin/parent/student/teacher web_test)

src/app/(dashboard)/teacher/grades/stats/page.tsx

@@ -1,23 +1,21 @@
-import { db } from "@/shared/db"
-import { subjects } from "@/shared/db/schema"
-import { asc } from "drizzle-orm"
+import type { JSX } from "react"
 import { getTeacherClasses } from "@/modules/classes/data-access"
 import { getClassGradeStatsWithMeta, getClassRanking } from "@/modules/grades/data-access"
+import { getSubjectOptions } from "@/modules/school/data-access"
 import { ClassGradeReport } from "@/modules/grades/components/class-grade-report"
 import { ExportButton } from "@/modules/grades/components/export-button"
+import { StatsClassSelector } from "@/modules/grades/components/stats-class-selector"
 import { EmptyState } from "@/shared/components/ui/empty-state"
+import { getParam, type SearchParams } from "@/shared/lib/search-params"
 import { BarChart3 } from "lucide-react"
 
 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 StatsPage({ searchParams }: { searchParams: Promise<SearchParams> }) {
+export default async function StatsPage({
+  searchParams,
+}: {
+  searchParams: Promise<SearchParams>
+}): Promise<JSX.Element> {
   const sp = await searchParams
 
   const classId = getParam(sp, "classId")
@@ -25,14 +23,14 @@ export default async function StatsPage({ searchParams }: { searchParams: Promis
 
   const [classes, allSubjects] = await Promise.all([
     getTeacherClasses(),
-    db.query.subjects.findMany({ orderBy: [asc(subjects.order), asc(subjects.name)] }),
+    getSubjectOptions(),
   ])
 
   if (classes.length === 0) {
     return (
       <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
         <div>
-          <h2 className="text-2xl font-bold tracking-tight">Grade Statistics</h2>
+          <h1 className="text-2xl font-bold tracking-tight">Grade Statistics</h1>
           <p className="text-muted-foreground">View class grade statistics and rankings.</p>
         </div>
         <EmptyState
@@ -60,7 +58,7 @@ export default async function StatsPage({ searchParams }: { searchParams: Promis
     <div className="h-full flex-1 flex-col space-y-8 p-8 md:flex">
       <div className="flex items-center justify-between">
         <div>
-          <h2 className="text-2xl font-bold tracking-tight">Grade Statistics</h2>
+          <h1 className="text-2xl font-bold tracking-tight">Grade Statistics</h1>
           <p className="text-muted-foreground">View class grade statistics and rankings.</p>
         </div>
         <ExportButton
@@ -82,58 +80,3 @@ export default async function StatsPage({ searchParams }: { searchParams: Promis
     </div>
   )
 }
-
-function StatsClassSelector({
-  classes,
-  subjects,
-  currentClassId,
-  currentSubjectId,
-}: {
-  classes: Array<{ id: string; name: string }>
-  subjects: Array<{ id: string; name: string }>
-  currentClassId: string
-  currentSubjectId: string
-}) {
-  return (
-    <div className="flex flex-wrap gap-2">
-      {classes.map((c) => (
-        <a
-          key={c.id}
-          href={`/teacher/grades/stats?classId=${c.id}${currentSubjectId !== "all" ? `&subjectId=${currentSubjectId}` : ""}`}
-          className={`rounded-md border px-3 py-1.5 text-sm transition-colors ${
-            c.id === currentClassId
-              ? "border-primary bg-primary text-primary-foreground"
-              : "bg-card hover:bg-accent"
-          }`}
-        >
-          {c.name}
-        </a>
-      ))}
-      <div className="ml-auto flex flex-wrap gap-2">
-        <a
-          href={`/teacher/grades/stats?classId=${currentClassId}`}
-          className={`rounded-md border px-3 py-1.5 text-sm transition-colors ${
-            currentSubjectId === "all"
-              ? "border-primary bg-primary text-primary-foreground"
-              : "bg-card hover:bg-accent"
-          }`}
-        >
-          All Subjects
-        </a>
-        {subjects.map((s) => (
-          <a
-            key={s.id}
-            href={`/teacher/grades/stats?classId=${currentClassId}&subjectId=${s.id}`}
-            className={`rounded-md border px-3 py-1.5 text-sm transition-colors ${
-              s.id === currentSubjectId
-                ? "border-primary bg-primary text-primary-foreground"
-                : "bg-card hover:bg-accent"
-            }`}
-          >
-            {s.name}
-          </a>
-        ))}
-      </div>
-    </div>
-  )
-}