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/exams/all/page.tsx

@@ -1,3 +1,4 @@
+import type { JSX } from "react"
 import { Suspense } from "react"
 import Link from "next/link"
 import { Button } from "@/shared/components/ui/button"
@@ -9,16 +10,10 @@ import { examColumns } from "@/modules/exams/components/exam-columns"
 import { ExamFilters } from "@/modules/exams/components/exam-filters"
 import { getExams } from "@/modules/exams/data-access"
 import { getAuthContext } from "@/shared/lib/auth-guard"
+import { getParam, type SearchParams } from "@/shared/lib/search-params"
 import { FileText, PlusCircle } from "lucide-react"
 
-type SearchParams = { [key: string]: string | string[] | undefined }
-
-const getParam = (params: SearchParams, key: string) => {
-  const v = params[key]
-  return Array.isArray(v) ? v[0] : v
-}
-
-async function ExamsResults({ searchParams }: { searchParams: Promise<SearchParams> }) {
+async function ExamsResults({ searchParams }: { searchParams: Promise<SearchParams> }): Promise<JSX.Element> {
   const params = await searchParams
   const { dataScope } = await getAuthContext()
 
@@ -62,7 +57,7 @@ async function ExamsResults({ searchParams }: { searchParams: Promise<SearchPara
         <div className="flex items-center gap-2">
           <Button asChild size="sm">
             <Link href="/teacher/exams/create" className="inline-flex items-center gap-2">
-              <PlusCircle className="h-4 w-4" />
+              <PlusCircle className="h-4 w-4" aria-hidden="true" />
               Create Exam
             </Link>
           </Button>
@@ -131,7 +126,7 @@ export default async function AllExamsPage({
   searchParams,
 }: {
   searchParams: Promise<SearchParams>
-}) {
+}): Promise<JSX.Element> {
   return (
     <div className="flex h-full flex-col space-y-8 p-8">
       <div className="space-y-4">