Assembles tasks 1/6/7/8 into a runnable cmd/server binary: QueueServiceServer
handlers translating kafkamgmt.v1 proto to internal/core/queue's plain Go
types, a lazy per-queue Kafka consumer registry for ReceiveMessage, and a
Redis-scan-based queue discovery loop that starts a reaper goroutine per
queue (queue lifecycle isn't exposed over gRPC, so this is the server's only
signal). Promotes kmsvc-proto to a direct go.mod dependency.
Handler-level integration tests run against kfake+miniredis (same documented
tradeoff as tasks 5-7's envtest/testcontainers substitution), exercising
send->receive->delete through the real QueueServiceServer implementation.
JWKS caching via lestrrat-go/jwx, signature/iss/aud/exp validation, and
a single gRPC interceptor that grpc-gateway's forwarded headers make
work identically for REST callers.
riotpiaole