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/shared/configure-app.ts

@@ -0,0 +1,18 @@
+// services/api/src/shared/configure-app.ts —— 应用级配置（全局前缀 / CORS /
+// 响应头），main-cn.ts 生产引导与 e2e 测试装配共用同一函数：此前 e2e 各 spec
+// 手工镜像 setGlobalPrefix，两处漂移无从守护；收敛为单一来源后，e2e 对
+// x-powered-by 头的断言才真正落在生产引导路径上（P1a 终审修缮②）。
+// 参数类型取 NestExpressApplication：disable() 是 Express 适配器特有方法。
+import type { NestExpressApplication } from '@nestjs/platform-express';
+import { API_PREFIX } from './constants';
+
+export function configureApp(app: NestExpressApplication): void {
+  app.setGlobalPrefix(API_PREFIX);
+  // 隐藏 Express x-powered-by 指纹响应头（终审修缮②，e2e 断言之）。
+  app.disable('x-powered-by');
+  const corsOrigins = (process.env.CORS_ORIGINS ?? 'http://localhost:5173')
+    .split(',')
+    .map((origin) => origin.trim())
+    .filter((origin) => origin !== '');
+  app.enableCors({ origin: corsOrigins });
+}