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/dashboard/page.tsx

@@ -1,26 +1,24 @@
+import type { JSX } from "react"
 import { TeacherDashboardView } from "@/modules/dashboard/components/teacher-dashboard/teacher-dashboard-view"
-import { getClassSchedule, getTeacherClasses, getTeacherIdForMutations } from "@/modules/classes/data-access";
-import { getHomeworkAssignments, getHomeworkSubmissions, getTeacherGradeTrends } from "@/modules/homework/data-access";
-import { db } from "@/shared/db";
-import { users } from "@/shared/db/schema";
-import { eq } from "drizzle-orm";
+import { getClassSchedule, getTeacherClasses, getTeacherIdForMutations } from "@/modules/classes/data-access"
+import { getHomeworkAssignments, getHomeworkSubmissions, getTeacherGradeTrends } from "@/modules/homework/data-access"
+import { getUserBasicInfo } from "@/modules/users/data-access"
+import { getAuthContext } from "@/shared/lib/auth-guard"
 
-export const dynamic = "force-dynamic";
+export const dynamic = "force-dynamic"
 
-export default async function TeacherDashboardPage() {
-  const teacherId = await getTeacherIdForMutations();
+export default async function TeacherDashboardPage(): Promise<JSX.Element> {
+  await getAuthContext()
+  const teacherId = await getTeacherIdForMutations()
 
   const [classes, schedule, assignments, submissions, teacherProfile, gradeTrends] = await Promise.all([
     getTeacherClasses({ teacherId }),
     getClassSchedule({ teacherId }),
     getHomeworkAssignments({ creatorId: teacherId }),
     getHomeworkSubmissions({ creatorId: teacherId }),
-    db.query.users.findFirst({
-      where: eq(users.id, teacherId),
-      columns: { name: true },
-    }),
+    getUserBasicInfo(teacherId),
     getTeacherGradeTrends(teacherId),
-  ]);
+  ])
 
   return (
     <TeacherDashboardView