chore(api): p1a final-review hygiene items

- contracts: add NOT_FOUND error code (framework-level 404 for unknown
  routes); Error enum + regen committed
- api: 404 default mapping in AllExceptionsFilter now NOT_FOUND (was
  ALBUM_NOT_FOUND); business 404s unchanged via explicit ApiException codes
- api: extract configureApp (prefix/CORS/x-powered-by) shared by main-cn
  bootstrap and e2e; disable x-powered-by, asserted in e2e
- api: move parseCursor/parseLimit (+page-size bounds) from
  albums.controller to shared/pagination; members/uploads/public re-pointed
- infra: bind compose published ports to 127.0.0.1 (mysql/redis/minio);
  .env.example endpoints follow suit
- e2e: unknown-route 404 NOT_FOUND + x-powered-by absent cases added
  (api e2e 120 -> 122)

Co-Authored-By: Claude Code <noreply@anthropic.com>

services/api/src/main-cn.ts

@@ -2,23 +2,18 @@
 // cn-app 部署入口（P1a 仅此一个 API 入口）。构建产物 dist/main-cn.js 由根 dev:api /
 // 生产启动命令运行；env 一律来自进程环境（根 dotenv-cli 注入），此处不读文件。
 import 'reflect-metadata';
-import { type INestApplication } from '@nestjs/common';
 import { NestFactory } from '@nestjs/core';
+import { type NestExpressApplication } from '@nestjs/platform-express';
 import { Logger } from 'nestjs-pino';
 import { AppCnModule } from './app-cn.module';
-import { API_PREFIX } from './shared/constants';
+import { configureApp } from './shared/configure-app';
 
 async function bootstrap(): Promise<void> {
-  const app = await NestFactory.create<INestApplication>(AppCnModule, {
+  const app = await NestFactory.create<NestExpressApplication>(AppCnModule, {
     bufferLogs: true,
   });
   app.useLogger(app.get(Logger));
-  app.setGlobalPrefix(API_PREFIX);
-  const corsOrigins = (process.env.CORS_ORIGINS ?? 'http://localhost:5173')
-    .split(',')
-    .map((origin) => origin.trim())
-    .filter((origin) => origin !== '');
-  app.enableCors({ origin: corsOrigins });
+  configureApp(app);
   const port = Number.parseInt(process.env.PORT ?? '', 10) || 8080;
   await app.listen(port);
   app.get(Logger).log(`api-cn listening on port ${port}`);