feat: 班级小助手 阶段1-3（monorepo + 后端 REST/Socket.IO + Web 管理端）

packages/server/src/app.ts

@@ -0,0 +1,57 @@
+import express, { type Express, type Request, type Response } from 'express';
+import cors from 'cors';
+import { API_PREFIX } from '@classhelper/shared';
+import { env } from './config/env.js';
+import { pingDatabase } from './lib/db.js';
+import { sendOk } from './lib/http.js';
+import { logger } from './lib/logger.js';
+import { errorHandler, notFoundHandler } from './middleware/error.js';
+import { apiModules } from './modules/registry.js';
+
+async function healthHandler(_req: Request, res: Response): Promise<void> {
+  sendOk(
+    res,
+    {
+      status: 'ok',
+      version: '0.1.0',
+      uptimeSeconds: Math.round(process.uptime()),
+      database: {
+        provider: env.databaseProvider,
+        connected: await pingDatabase(),
+      },
+      modules: apiModules.map((module) => module.name),
+    },
+    '服务运行正常',
+  );
+}
+
+/** 组装 Express 应用：中间件 -> 健康检查 -> 模块路由 -> 404 -> 统一错误处理 */
+export function createApp(): Express {
+  const app = express();
+  app.disable('x-powered-by');
+
+  app.use(cors({ origin: env.corsOrigins, credentials: true }));
+  app.use(express.json({ limit: '2mb' }));
+  app.use(express.urlencoded({ extended: true }));
+
+  app.use((req, _res, next) => {
+    logger.debug(`${req.method} ${req.originalUrl}`);
+    next();
+  });
+
+  // 健康检查（同时暴露已挂载模块列表，便于确认模块化装配结果）
+  app.get(`${API_PREFIX}/health`, healthHandler);
+  app.get('/health', healthHandler);
+
+  // 模块化装配：注册表里的每个模块挂载到 /api<basePath>
+  for (const module of apiModules) {
+    const mountPath = `${API_PREFIX}${module.basePath}`;
+    app.use(mountPath, module.router);
+    logger.info(`已挂载模块 ${module.name.padEnd(14)} -> ${mountPath}`);
+  }
+
+  app.use(notFoundHandler);
+  app.use(errorHandler);
+
+  return app;
+}