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。

packages/shared/vitest.config.ts

@@ -0,0 +1,15 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    environment: 'node',
+    include: ['src/**/*.spec.ts'],
+    coverage: {
+      provider: 'v8',
+      reporter: ['text', 'lcov', 'json-summary'],
+      include: ['src/**/*.ts'],
+      exclude: ['src/**/*.spec.ts', 'src/index.ts', 'src/**/index.ts'],
+      thresholds: { lines: 85, functions: 85, statements: 85, branches: 80 },
+    },
+  },
+});