feat(content): 修复服务并添加chapters/knowledge-points/questions模块

- database.ts 导出db常量替代getDb()函数

- env.ts JWT_SECRET/ES_URL/NEO4J_URL改optional加DEV_MODE

- neo4j.ts driver惰性创建+try/catch+connectionTimeout:3000

- health/lifecycle改用Drizzle原生查询

- textbooks.schema修复integer到int+导出NewTextbook类型

- 新建chapters/knowledge-points/questions三模块CRUD

- knowledge-points含Neo4j前置依赖图非阻塞查询

- content-init.sql创建4张表

端到端验证: textbooks/chapters/knowledge-points/questions全CRUD通过

services/content/src/chapters/chapters.controller.ts

@@ -0,0 +1,61 @@
+import {
+  Body,
+  Controller,
+  Delete,
+  Get,
+  Param,
+  Post,
+  Put,
+} from "@nestjs/common";
+import {
+  ChaptersService,
+  type CreateChapterInput,
+  type UpdateChapterInput,
+} from "./chapters.service.js";
+import type { Chapter } from "./chapters.schema.js";
+
+@Controller("chapters")
+export class ChaptersController {
+  constructor(private readonly service: ChaptersService) {}
+
+  @Post()
+  async create(
+    @Body() body: CreateChapterInput,
+  ): Promise<{ success: true; data: { id: string } }> {
+    const result = await this.service.createChapter(body);
+    return { success: true, data: result };
+  }
+
+  @Get("textbook/:textbookId")
+  async listByTextbook(
+    @Param("textbookId") textbookId: string,
+  ): Promise<{ success: true; data: Chapter[] }> {
+    const data = await this.service.listChaptersByTextbook(textbookId);
+    return { success: true, data };
+  }
+
+  @Get(":id")
+  async getById(
+    @Param("id") id: string,
+  ): Promise<{ success: true; data: Chapter }> {
+    const data = await this.service.getChapter(id);
+    return { success: true, data };
+  }
+
+  @Put(":id")
+  async update(
+    @Param("id") id: string,
+    @Body() body: UpdateChapterInput,
+  ): Promise<{ success: true; data: { success: true } }> {
+    await this.service.updateChapter(id, body);
+    return { success: true, data: { success: true } };
+  }
+
+  @Delete(":id")
+  async remove(
+    @Param("id") id: string,
+  ): Promise<{ success: true; data: { success: true } }> {
+    await this.service.deleteChapter(id);
+    return { success: true, data: { success: true } };
+  }
+}

services/content/src/chapters/chapters.module.ts

@@ -0,0 +1,10 @@
+import { Module } from "@nestjs/common";
+import { ChaptersController } from "./chapters.controller.js";
+import { ChaptersService } from "./chapters.service.js";
+
+@Module({
+  controllers: [ChaptersController],
+  providers: [ChaptersService],
+  exports: [ChaptersService],
+})
+export class ChaptersModule {}

services/content/src/chapters/chapters.repository.ts

@@ -0,0 +1,35 @@
+import { eq } from "drizzle-orm";
+import { db } from "../config/database.js";
+import { chapters, type Chapter, type NewChapter } from "./chapters.schema.js";
+
+export class ChaptersRepository {
+  async findById(id: string): Promise<Chapter | undefined> {
+    const [result] = await db
+      .select()
+      .from(chapters)
+      .where(eq(chapters.id, id))
+      .limit(1);
+    return result;
+  }
+
+  async findByTextbookId(textbookId: string): Promise<Chapter[]> {
+    return db
+      .select()
+      .from(chapters)
+      .where(eq(chapters.textbookId, textbookId));
+  }
+
+  async create(data: NewChapter): Promise<void> {
+    await db.insert(chapters).values(data);
+  }
+
+  async update(id: string, data: Partial<NewChapter>): Promise<void> {
+    await db.update(chapters).set(data).where(eq(chapters.id, id));
+  }
+
+  async delete(id: string): Promise<void> {
+    await db.delete(chapters).where(eq(chapters.id, id));
+  }
+}
+
+export const chaptersRepository = new ChaptersRepository();

services/content/src/chapters/chapters.schema.ts

@@ -0,0 +1,5 @@
+export {
+  chapters,
+  type Chapter,
+  type NewChapter,
+} from "../textbooks/textbooks.schema.js";

services/content/src/chapters/chapters.service.ts

@@ -0,0 +1,62 @@
+import { randomUUID } from "node:crypto";
+import { Injectable } from "@nestjs/common";
+import { chaptersRepository } from "./chapters.repository.js";
+import type { Chapter } from "./chapters.schema.js";
+import {
+  NotFoundError,
+  ValidationError,
+} from "../shared/errors/application-error.js";
+
+export interface CreateChapterInput {
+  textbookId: string;
+  title: string;
+  order: number;
+  parentId?: string;
+}
+
+export interface UpdateChapterInput {
+  title?: string;
+  order?: number;
+  parentId?: string;
+}
+
+@Injectable()
+export class ChaptersService {
+  async createChapter(input: CreateChapterInput): Promise<{ id: string }> {
+    if (!input.textbookId || !input.title || input.order === undefined) {
+      throw new ValidationError("textbookId, title, order are required");
+    }
+
+    const id = randomUUID();
+    await chaptersRepository.create({
+      id,
+      textbookId: input.textbookId,
+      title: input.title,
+      order: input.order,
+      parentId: input.parentId,
+    });
+    return { id };
+  }
+
+  async getChapter(id: string): Promise<Chapter> {
+    const chapter = await chaptersRepository.findById(id);
+    if (!chapter) {
+      throw new NotFoundError("Chapter", id);
+    }
+    return chapter;
+  }
+
+  async listChaptersByTextbook(textbookId: string): Promise<Chapter[]> {
+    return chaptersRepository.findByTextbookId(textbookId);
+  }
+
+  async updateChapter(id: string, data: UpdateChapterInput): Promise<void> {
+    await this.getChapter(id);
+    await chaptersRepository.update(id, data);
+  }
+
+  async deleteChapter(id: string): Promise<void> {
+    await this.getChapter(id);
+    await chaptersRepository.delete(id);
+  }
+}