feat: initial commit with accounts manager project structure

- TypeScript项目基础架构
- API路由和账户管理服务
- 数据库模式和迁移
- 基础配置文件和文档

🤖 Generated with [Claude Code](https://claude.ai/code)

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

.env.example

@@ -0,0 +1,9 @@
+# Database Configuration
+DATABASE_URL=postgresql://username:password@localhost:5432/accounts_db
+
+# Server Configuration
+PORT=3006
+NODE_ENV=development
+
+# Lock Timeout (in minutes)
+LOCK_TIMEOUT_MINUTES=30