refactor(api): split inference and control services

[connorcarpenter15]

Summary

• define openengine.v1.Inference for generation, embedding, classification, and scoring
• define openengine.v1.Control for discovery, lifecycle, LoRA management, KV coordination, and runtime events
• rename engine.proto to server.proto
• rename EngineInfo and GetEngineInfo to ServerInfo and GetServerInfo
• make the hosted engine role explicit as ServerInfo.engine_role while retaining the semantically accurate EngineRole enum
• advertise decode-context parallelism through ParallelismInfo.decode_context_parallel_size
• update the API reference and project documentation for the new names and service boundary

Why

The split keeps inference traffic on a small data-plane surface while coordination operations live on a separate control-plane service. Implementations can register both services on one listener or isolate Control by listener and access policy.

Inference is broader and more accurate than Generate because it also owns the non-generative task RPCs. The package-qualified names openengine.v1.Inference and openengine.v1.Control remain concise without losing context.

server.proto now matches its primary ServerInfo message. EngineRole remains engine-specific because aggregated, prefill, and decode describe execution roles rather than administrative server roles.

Compatibility

This is an intentional pre-adoption API refinement:

• RPC paths become /openengine.v1.Inference/* and /openengine.v1.Control/*
• GetEngineInfo, GetEngineInfoRequest, and EngineInfo become GetServerInfo, GetServerInfoRequest, and ServerInfo
• ServerInfo.role becomes ServerInfo.engine_role
• declarations in engine.proto move to server.proto
• decode_context_parallel_size is an additive optional field; when present it must be at least one, and one means DCP is disabled

Validation

• Buf lint
• direct protoc descriptor compilation
• Markdown lint
• documentation link checks
• DCO sign-off

[github-actions]

The latest Buf updates on your PR. Results from workflow Buf / schema (pull_request).

Build	Format	Lint	Breaking	Updated (UTC)
✅ passed	✅ passed	✅ passed	⏩ skipped	Jul 15, 2026, 4:11 PM