Add a Sealos deployment option to the quickstart

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**Is your feature request related to a problem? Please describe.**

The quickstart currently documents the local Docker Compose path. A tested Sealos template exists for users who run Coze Studio on Sealos, and the project documentation currently has no link to that deployment path.

**Describe the solution you'd like**

Add a short, docs-only Sealos deployment entry after the Docker quickstart in both `README.md` and `README.zh_CN.md`. The entry would include the standard Deploy on Sealos button and keep the existing public-network security warning visible next to the deployment instructions.

Proposed target: https://sealos.io/products/app-store/coze-studio

**Describe alternatives you've considered**

A provider-specific guide would carry more detail. A short bilingual README entry keeps the contribution small and points users to the maintained template documentation for configuration and troubleshooting.

**Additional context**

- Template version: Coze Studio `0.5.1`
- Tested deployment: 2026-08-05
- The template provisions the web and server workloads together with MySQL, Redis, NSQ, etcd, Elasticsearch, Milvus, and private object storage.
- Secrets are generated or entered during deployment and are not stored in the upstream repository.
- Browser smoke covered registration and representative navigation.
- Runtime log scans ended with zero active failures, and all verification resources were cleaned up.
- I can maintain the Sealos deployment path and follow up when the template or docs need updates.

Read the Docker quickstart sections in README.md and README.zh_CN.md to match their structure and locate the existing public-network security warning. Add the short bilingual Sealos entry after those sections, including the Deploy on Sealos button linking to the proposed template, while keeping the warning visible in both files.

Written by the indexing model from the issue text.