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

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

clients/rust/src/client.rs

@@ -327,6 +327,9 @@ impl GatewayClient {
     /// MXAccess session; the resulting native MxStatus is returned in the
     /// reply. Acks are idempotent at the MxAccess layer.
     ///
+    /// `operator_user` is required; `operator_password` may be empty. The
+    /// password is scrubbed from any returned error's `Display`/`Debug`.
+    ///
     /// # Errors
     ///
     /// Returns [`Error::ProtocolStatus`] when the gateway accepts the call but
@@ -336,13 +339,19 @@ impl GatewayClient {
         &self,
         request: AcknowledgeAlarmRequest,
     ) -> Result<AcknowledgeAlarmReply, Error> {
+        let secret = request.operator_password.clone();
         let mut client = self.inner.clone();
-        let response = client
-            .acknowledge_alarm(self.unary_request(request))
-            .await?;
-        let reply = response.into_inner();
-        ensure_protocol_success("acknowledge alarm", reply.protocol_status.as_ref())?;
-        Ok(reply)
+        let result = async {
+            let response = client
+                .acknowledge_alarm(self.unary_request(request))
+                .await?;
+            let reply = response.into_inner();
+            ensure_protocol_success("acknowledge alarm", reply.protocol_status.as_ref())?;
+            Ok(reply)
+        }
+        .await;
+        // The operator password must never surface in a returned error.
+        result.map_err(|error: Error| error.redact_secrets(&[secret.as_str()]))
     }
 
     /// Open the server-streaming `QueryActiveAlarms` RPC — the gateway's