feat(api): 搭建 API 与 Worker 骨架及契约基线

NestJS 11 + Fastify 统一错误体与 trace_id，/health 真实探活 DB/Redis，OpenAPI 3.1 契约含 20 个错误码；shared 包提供错误码、权限点、ULID、分页与通用 schema；worker 完成队列进程骨架。

apps/worker/src/main.ts

@@ -0,0 +1,62 @@
+import { existsSync } from 'node:fs';
+import { resolve } from 'node:path';
+
+import { config as loadDotenvFile } from 'dotenv';
+import Redis from 'ioredis';
+import pino from 'pino';
+
+import { loadWorkerConfig } from './config';
+
+function loadDotenv(): void {
+  for (const file of ['.env.local', '.env']) {
+    const path = resolve(process.cwd(), file);
+    if (existsSync(path)) {
+      loadDotenvFile({ path });
+    }
+  }
+}
+
+async function main(): Promise<void> {
+  loadDotenv();
+  const config = loadWorkerConfig();
+  const logger = pino({ level: config.logLevel, base: { service: 'lingxi-worker' } });
+
+  const redis = new Redis(config.redisUrl, {
+    lazyConnect: true,
+    maxRetriesPerRequest: null,
+    enableOfflineQueue: false,
+  });
+  redis.on('error', (error: Error) => {
+    logger.error({ err: error }, 'redis connection error');
+  });
+
+  await redis.connect();
+  await redis.ping();
+  logger.info({ queue: config.queue, concurrency: config.concurrency }, 'worker 已启动，等待任务');
+
+  // A0 只验证进程与依赖可用；BullMQ 消费者在 M1 批次接入（QUEUE 环境变量决定队列）
+  const heartbeat = setInterval(() => {
+    logger.debug({ queue: config.queue }, 'worker heartbeat');
+  }, 30_000);
+  heartbeat.unref();
+
+  const shutdown = async (signal: string): Promise<void> => {
+    clearInterval(heartbeat);
+    logger.info({ signal }, 'worker 正在退出');
+    await redis.quit();
+  };
+
+  process.on('SIGINT', () => {
+    void shutdown('SIGINT');
+  });
+  process.on('SIGTERM', () => {
+    void shutdown('SIGTERM');
+  });
+}
+
+void main().catch((error: unknown) => {
+  process.stderr.write(
+    `Worker 启动失败：${error instanceof Error ? (error.stack ?? error.message) : String(error)}\n`,
+  );
+  process.exitCode = 1;
+});