feat(platform): Implement platform infrastructure with cloud-native support

- Add storage service (LocalAdapter + OSSAdapter stub)
- Add database connection pool with graceful shutdown
- Add logging system with winston (JSON format)
- Add environment config management
- Add async job queue (MemoryQueue + DatabaseQueue stub)
- Add cache service (MemoryCache + RedisCache stub)
- Add health check endpoints for SAE
- Add monitoring metrics for DB, memory, API

Key Features:
- Zero-code switching between local and cloud environments
- Adapter pattern for multi-environment support
- Backward compatible with legacy modules
- Ready for Aliyun Serverless deployment

Related: Platform Infrastructure Planning (docs/09-鏋舵瀯瀹炴柦/04-骞冲彴鍩虹璁炬柦瑙勫垝.md)

backend/src/common/health/index.ts

@@ -0,0 +1,26 @@
+/**
+ * 健康检查统一导出
+ * 
+ * 提供SAE健康检查端点，用于存活和就绪探测。
+ * 
+ * @module health
+ * 
+ * @example
+ * ```typescript
+ * import { registerHealthRoutes } from '@/common/health'
+ * import Fastify from 'fastify'
+ * 
+ * const app = Fastify()
+ * 
+ * // 注册健康检查路由
+ * await registerHealthRoutes(app)
+ * 
+ * // SAE配置示例：
+ * // - Liveness Probe: GET /health/liveness (每10秒检查一次)
+ * // - Readiness Probe: GET /health/readiness (每5秒检查一次)
+ * ```
+ */
+
+export { registerHealthRoutes } from './healthCheck.js'
+export type { HealthCheckResponse } from './healthCheck.js'
+