Phase 3 Task 3. Central serves the deployment artifact over a dedicated h2c
Kestrel listener (ConfigServe:GrpcListenPort), gated by the ConfigServeAuthInterceptor
(shared bearer key, FixedTimeEquals, fail-closed, path-scoped to
/deployment_artifact.v1.DeploymentArtifactService/). The listener block is merged
with the LocalDb-sync listener so a fused admin+driver node re-applies its existing
HTTP surface exactly ONCE and adds both dedicated h2c ports on top — double-binding
would throw 'address already in use'; zero re-binding would silently unbind the
AdminUI behind Traefik. AddGrpc now registers under hasDriver || hasAdmin with both
path-scoped interceptors sharing one pipeline.
Claude-Session: https://claude.ai/code/session_01GASWkNEi68FSCtvr6rLoEW