Complete Docker compose deployment setup

- Add an API container entrypoint that waits for PostgreSQL, runs Prisma migrations, seeds demo data, and then starts NestJS.

- Keep Prisma CLI and seed dependencies available in the API runtime image and copy seed source dependencies into the container.

- Add Docker Compose healthchecks and health-based startup ordering for PostgreSQL, API, and Nginx web services.

- Add Docker initialization environment switches for migrations, seed, and startup retries.

- Add a dedicated Docker deployment guide covering services, ports, initialization, HTTPS, production variables, backup, restore, and troubleshooting.

- Update README, AGENTS, installation, deployment, progress, and environment example docs for the Dockerized workflow.

docs/README.md

@@ -16,6 +16,7 @@
 - [后端化与用户化改造方案](./backendization-plan.md)：前后端拆分、数据模型、API、权限、安全和迁移阶段。
 - [数据与存储](./data-storage.md)：`localStorage` / `sessionStorage` 键、数据生命周期和迁移点。
 - [部署运行](./deployment.md)：本地开发、后端 API、构建、Docker Compose 和 Nginx 部署方式。
+- [Docker 化部署](./docker.md)：完整 Compose 服务、初始化脚本、健康检查、HTTPS、生产变量和备份恢复。
 - [安全说明](./security.md)：当前安全边界、敏感信息风险和生产化建议。
 
 ## 模块文档