Go client: port stream-alarms and acknowledge-alarm

Adds the session-less alarm CLI subcommands to mxgw-go. stream-alarms attaches
to the gateway's central alarm feed (--filter-prefix, --limit, --json — NDJSON,
one AlarmFeedMessage per line); acknowledge-alarm is a unary ack (--reference
required, --comment, --operator). StreamAlarms joins QueryActiveAlarms on the
public Client and is wired through the existing batch dispatcher via runWithIO.
SDK type aliases for StreamAlarmsRequest / AlarmFeedMessage / StreamAlarmsClient
land alongside the existing alarm types.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

clients/go/mxgateway/alarms.go

@@ -51,3 +51,26 @@ func (c *Client) QueryActiveAlarms(ctx context.Context, req *QueryActiveAlarmsRe
 
 	return stream, nil
 }
+
+// StreamAlarms attaches to the gateway's central alarm feed. The stream opens
+// with one AlarmFeedMessage per currently-active alarm (the ConditionRefresh
+// snapshot), then a single snapshot-complete sentinel, then a transition for
+// every subsequent raise / acknowledge / clear. It is served by the gateway's
+// always-on alarm monitor — no worker session is opened — so any number of
+// clients may attach.
+//
+// The returned stream is owned by the caller; cancel ctx to release it.
+// Optional alarm-reference prefix scoping (req.AlarmFilterPrefix) limits the
+// stream to a sub-tree.
+func (c *Client) StreamAlarms(ctx context.Context, req *StreamAlarmsRequest) (StreamAlarmsClient, error) {
+	if req == nil {
+		return nil, errors.New("mxgateway: stream alarms request is required")
+	}
+
+	stream, err := c.raw.StreamAlarms(ctx, req)
+	if err != nil {
+		return nil, &GatewayError{Op: "stream alarms", Err: err}
+	}
+
+	return stream, nil
+}

clients/go/mxgateway/alarms_test.go

@@ -147,8 +147,8 @@ func TestQueryActiveAlarmsPassesFilterPrefix(t *testing.T) {
 	defer cleanup()
 
 	stream, err := client.QueryActiveAlarms(context.Background(), &pb.QueryActiveAlarmsRequest{
-		SessionId:          "session-1",
-		AlarmFilterPrefix:  "Tank01.",
+		SessionId:         "session-1",
+		AlarmFilterPrefix: "Tank01.",
 	})
 	if err != nil {
 		t.Fatalf("QueryActiveAlarms() error = %v", err)

clients/go/mxgateway/galaxy_test.go

@@ -55,8 +55,8 @@ func TestGalaxyGetLastDeployTimeReturnsTimestampWhenPresent(t *testing.T) {
 	want := time.Date(2026, 4, 28, 12, 34, 56, 0, time.UTC)
 	fake := &fakeGalaxyServer{
 		deployReply: &pb.GetLastDeployTimeReply{
-			Present:           true,
-			TimeOfLastDeploy:  timestamppb.New(want),
+			Present:          true,
+			TimeOfLastDeploy: timestamppb.New(want),
 		},
 	}
 	client, cleanup := newGalaxyBufconnClient(t, fake)

clients/go/mxgateway/types.go

@@ -112,6 +112,11 @@ type (
 	AcknowledgeAlarmReply = pb.AcknowledgeAlarmReply
 	// QueryActiveAlarmsRequest is the gateway QueryActiveAlarms request message.
 	QueryActiveAlarmsRequest = pb.QueryActiveAlarmsRequest
+	// StreamAlarmsRequest is the gateway StreamAlarms request message.
+	StreamAlarmsRequest = pb.StreamAlarmsRequest
+	// AlarmFeedMessage is one message on the StreamAlarms feed — an
+	// active-alarm snapshot row, a snapshot-complete sentinel, or a transition.
+	AlarmFeedMessage = pb.AlarmFeedMessage
 	// ActiveAlarmSnapshot is one row in a ConditionRefresh stream.
 	ActiveAlarmSnapshot = pb.ActiveAlarmSnapshot
 	// OnAlarmTransitionEvent is the body carried by alarm-transition MxEvents.
@@ -130,6 +135,10 @@ type AlarmConditionState = pb.AlarmConditionState
 // QueryActiveAlarms RPC.
 type QueryActiveAlarmsClient = pb.MxAccessGateway_QueryActiveAlarmsClient
 
+// StreamAlarmsClient is the generated server-streaming client for the
+// StreamAlarms RPC.
+type StreamAlarmsClient = pb.MxAccessGateway_StreamAlarmsClient
+
 // Enumerations from the generated contract re-exported for client callers.
 type (
 	// MxCommandKind discriminates which MXAccess command an MxCommand carries.