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/modules/lesson-preparation/ai-suggest.ts

@@ -0,0 +1,65 @@
+import "server-only";
+
+import { env } from "@/env.mjs";
+import { createAiChatCompletion } from "@/shared/lib/ai";
+import {
+  getKnowledgePointsByTextbookId,
+  getKnowledgePointsByChapterId,
+} from "@/modules/textbooks/data-access";
+import type { LessonPlanDocument } from "./types";
+
+export async function suggestKnowledgePoints(
+  doc: LessonPlanDocument,
+  textbookId?: string,
+  chapterId?: string,
+): Promise<{ id: string; name: string; reason: string }[]> {
+  // 1. 提取课案纯文本
+  const text = doc.nodes
+    .map((b) => {
+      const d = b.data as { html?: string; sourceText?: string };
+      return d.html ?? d.sourceText ?? "";
+    })
+    .join("\n")
+    .slice(0, 3000);
+
+  if (!text.trim()) return [];
+
+  // 2. 获取候选知识点池
+  if (!textbookId) return [];
+  const allKps = chapterId
+    ? await getKnowledgePointsByChapterId(chapterId)
+    : await getKnowledgePointsByTextbookId(textbookId);
+  if (allKps.length === 0) return [];
+
+  const kpList = allKps.map((kp) => ({ id: kp.id, name: kp.name })).slice(0, 100);
+
+  // 3. 调用 AI
+  const prompt = `你是教学设计助手。以下是教师备课内容：
+---
+${text}
+---
+请从下列知识点中推荐最相关的 3-8 个，并说明理由。返回 JSON 数组，每项含 id/name/reason。
+候选知识点：${JSON.stringify(kpList)}`;
+
+  const { content } = await createAiChatCompletion({
+    messages: [{ role: "user", content: prompt }],
+    model: env.AI_MODEL ?? "gpt-4o-mini",
+    temperature: 0.3,
+  });
+
+  try {
+    // 尝试从返回内容中提取 JSON 数组
+    const jsonMatch = content.match(/\[[\s\S]*\]/);
+    if (!jsonMatch) return [];
+    const parsed = JSON.parse(jsonMatch[0]) as {
+      id: string;
+      name: string;
+      reason: string;
+    }[];
+    // 过滤掉不在候选池中的 id
+    const validIds = new Set(kpList.map((k) => k.id));
+    return parsed.filter((p) => validIds.has(p.id));
+  } catch {
+    return [];
+  }
+}