protos: consider adopting linting and api design rules.

[tmc]

Hi! Super interesting project! I always beeline to protos or other api specs.

Can I suggest that https://buf.build/docs/lint/rules#minimal and /or https://linter.aip.dev/ are leveraged to help normalize the proto representation?

[wenfengwang]

Thanks @tmc for your guide! we will fix it! NPi is actively developing, there are many bad smelling in the codebase, any point out is very appreciated!