feat(go-client): operator credentials on acknowledge-alarm

Claude-Session: https://claude.ai/code/session_016J6isfcgqy4SB2RK3ZvFvT

clients/go/README.md

@@ -140,7 +140,11 @@ sentinel typed and observable; it never synthesizes or swallows it.
 
 For alarms, the package exposes `Client.QueryActiveAlarms` for one-shot
 snapshots, `Client.StreamAlarms` for the server-streaming feed, and
-`Client.AcknowledgeAlarm` to ack an alarm by full reference. The streaming
+`Client.AcknowledgeAlarm` to ack an alarm by full reference. Acks carry the
+operator's Galaxy credentials (`OperatorUser` required, `OperatorPassword`,
+optional `OperatorDomain`) so the gateway authenticates as the operator and the
+Historian records that operator; an empty password is allowed, and the password
+is scrubbed from any returned error. The streaming
 call returns a `StreamAlarmsClient`; cancel its context to terminate the
 stream. All three pass straight through to the gateway's central alarm
 monitor.
@@ -424,7 +428,7 @@ Every subcommand wired into the CLI. All accept the common flags
 | `bench-read-bulk` | Throughput benchmark (`-duration-seconds`, `-warmup-seconds`, `-bulk-size`). |
 | `stream-events` | Stream item-value events for a session (`-session-id`, `-limit`). |
 | `stream-alarms` | Stream the alarm feed (`-filter-prefix`, `-limit`). |
-| `acknowledge-alarm` | Acknowledge an alarm reference. |
+| `acknowledge-alarm` | Acknowledge an alarm as an operator (`-operator`, `-operator-domain`, `-operator-password-env`, default `MXGATEWAY_OPERATOR_PASSWORD`). |
 | `smoke` | End-to-end smoke workflow against one item. |
 | `galaxy-test-connection` | Probe the Galaxy Repository RPC connection. |
 | `galaxy-last-deploy` | Print the most recent deploy event. |