[Feature] Maybe the password in docker-compose.yaml can be random rather than 123456?

### Feature Request

Hi, I had installed hertzbeat with docker compose, ref to :https://hertzbeat.apache.org/zh-cn/docs/start/docker-compose-deploy

But I found that the PostgreSQL username and password used by Hertzbeat are root/123456. That doesn't seem like a good idea in a production environment. After installed hertzbeat, I used db tools to connect my server with root/123456, and everything in hertzbeat shows.

Maybe something can be done? A random password, or using .env, or anything else.

Thanks

### Is your feature request related to a problem? Please describe

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### Describe the solution you'd like

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### Describe alternatives you've considered

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### Additional context

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Start with docker-compose.yaml and the Docker Compose deployment documentation linked in the issue. Trace how the PostgreSQL username and password are configured, then determine the supported secure configuration approach, such as generated credentials or .env values. Done means a fresh deployment no longer exposes the default password and HertzBeat can still connect to PostgreSQL.

Written by the indexing model from the issue text.