Proto definitions for 4 services (RegistryService, PolicyService,
AuditService, AdminService) with hand-written Go stubs using JSON
codec until protobuf tooling is available.
Interceptor chain: logging (method, peer IP, duration, never logs
auth metadata) → auth (bearer token via MCIAS, Health bypasses) →
admin (role check for GC, policy, delete, audit RPCs).
All RPCs share business logic with REST handlers via internal/db
and internal/gc packages. TLS 1.3 minimum on gRPC listener.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>