Append-only UInt64 epoch-millis field for the responder snapshot timestamp
(Req 11.1, wire-format setup). Hand-authored xce_ctrlstatus_t typemap gains a
matching responder_time_ms member; codec round-trips it. Controller suite 1/1 OK.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
EARS requirements for a controller status query (XCE lsid analog): primary identity
(unknown when unelected), answered-by node+role (distinct from cluster view),
configured peers+count, committed config version + content checksum (catch same-version
divergence), term/commit-apply/fenced/cluster-name, failover-aware delivery, test-client
command, and wait-primary switching its probe to it. C tier only.