[Feature] enable modular development like springboot modulith or google service weaver

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### Search before asking

- [X] I had searched in the [issues](https://github.com/apache/dubbo/issues?q=is%3Aissue) and found no similar feature requirement.

### Apache Dubbo Component

Java SDK (apache/dubbo)

### Descriptions

Currently, there are many concerns in modular development, no matter springboot modulith or google service weaver. We notice that we can achieve those benefit by the modular development.
1. developing with only focus on his own business
2. deploy much faster
3. cost less resource
4. more simper cooperation with other developers
5. and so on

So, How to enable modular development in dubbo? Can we discompose the mess code into small and separated modulars，develop and deploy separately (hot deploy).

### Related issues

_No response_

### Are you willing to submit a pull request to fix on your own?

- [X] Yes I am willing to submit a pull request on my own!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://www.apache.org/foundation/policies/conduct)

The issue provides no files, entry points, tests, or concrete acceptance criteria. Start by reviewing the Java SDK's existing module and deployment architecture, then compare the requested separation and hot-deployment behavior with Spring Boot Modulith and Google Service Weaver; done requires an agreed design and demonstrable modular development and deployment support.

Written by the indexing model from the issue text.