chore(api): grpc server (remove graphql)

[pront]

Summary

Metric	Before	After	Change
API implementation	5,999 lines	1,200 lines	-80%
Schema files	24 GraphQL files	1 proto file	-96%
Dependencies	async-graphql stack	tonic/prost	Dependency reduction

This PR migrates the Vector API from GraphQL to gRPC as an internal implementation detail with no user-facing changes. Users continue to use the same configuration with identical behavior and output. This refactoring improves performance and reduces dependencies without affecting the user experience, making it a pure internal improvement that requires no user action.

Vector configuration

How did you test this PR?

Change Type

• Bug fix
• New feature
• Non-functional (chore, refactoring, docs)
• Performance

Is this a breaking change?

• Yes
• No

Does this PR include user facing changes?

• Yes. Please add a changelog fragment based on our guidelines.
• No. A maintainer will apply the no-changelog label to this PR.

References

Notes

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