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)/admin/announcements/[id]/page.tsx

@@ -1,16 +1,23 @@
 import { notFound } from "next/navigation"
+import type { Metadata } from "next"
+import type { JSX } from "react"
 
 import { getAnnouncementById } from "@/modules/announcements/data-access"
 import { getGrades } from "@/modules/school/data-access"
 import { AnnouncementForm } from "@/modules/announcements/components/announcement-form"
 
+export const metadata: Metadata = {
+  title: "编辑公告 - Next_Edu",
+  description: "更新公告详情",
+}
+
 export const dynamic = "force-dynamic"
 
 export default async function EditAnnouncementPage({
   params,
 }: {
   params: Promise<{ id: string }>
-}) {
+}): Promise<JSX.Element> {
   const { id } = await params
 
   const [announcement, grades] = await Promise.all([
@@ -23,8 +30,8 @@ export default async function EditAnnouncementPage({
   return (
     <div className="flex h-full flex-col space-y-8 p-8">
       <div>
-        <h2 className="text-2xl font-bold tracking-tight">Edit Announcement</h2>
-        <p className="text-muted-foreground">Update the announcement details below.</p>
+        <h2 className="text-2xl font-bold tracking-tight">编辑公告</h2>
+        <p className="text-muted-foreground">更新公告详情。</p>
       </div>
       <AnnouncementForm
         mode="edit"

src/app/(dashboard)/admin/announcements/page.tsx

@@ -1,17 +1,19 @@
+import type { Metadata } from "next"
+import type { JSX } from "react"
+
 import { getAnnouncements } from "@/modules/announcements/data-access"
 import { getGrades } from "@/modules/school/data-access"
 import { AdminAnnouncementsView } from "@/modules/announcements/components/admin-announcements-view"
+import { getSearchParam, type SearchParams } from "@/shared/lib/utils"
 import type { AnnouncementStatus } from "@/modules/announcements/types"
 
-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 const metadata: Metadata = {
+  title: "公告管理 - Next_Edu",
+  description: "管理系统公告，支持草稿、发布与归档",
 }
 
+export const dynamic = "force-dynamic"
+
 const isValidStatus = (v?: string): v is AnnouncementStatus =>
   v === "draft" || v === "published" || v === "archived"
 
@@ -19,9 +21,9 @@ export default async function AdminAnnouncementsPage({
   searchParams,
 }: {
   searchParams: Promise<SearchParams>
-}) {
+}): Promise<JSX.Element> {
   const sp = await searchParams
-  const statusParam = getParam(sp, "status")
+  const statusParam = getSearchParam(sp, "status")
   const status = isValidStatus(statusParam) ? statusParam : undefined
 
   const [announcements, grades] = await Promise.all([