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/lesson-plans/new/page.tsx

@@ -0,0 +1,23 @@
+import type { JSX } from "react"
+import Link from "next/link"
+import { ArrowLeft } from "lucide-react"
+import { Button } from "@/shared/components/ui/button"
+import { TemplatePicker } from "@/modules/lesson-preparation/components/template-picker"
+
+export const dynamic = "force-dynamic"
+
+export default function NewLessonPlanPage(): JSX.Element {
+  return (
+    <div className="p-6">
+      <div className="mb-6 flex items-center gap-4">
+        <Button asChild variant="ghost" size="icon">
+          <Link href="/teacher/lesson-plans" aria-label="Back to lesson plans">
+            <ArrowLeft className="h-4 w-4" aria-hidden="true" />
+          </Link>
+        </Button>
+        <h1 className="text-2xl font-bold tracking-tight">New Lesson Plan</h1>
+      </div>
+      <TemplatePicker />
+    </div>
+  )
+}