Add stream-alarms and acknowledge-alarm to the .NET CLI

stream-alarms attaches to the gateway's central alarm feed (mirrors
stream-events: --max-events cap, --json/--jsonl, --filter-prefix);
acknowledge-alarm is a unary session-less ack (--reference required,
--comment, --operator). Both wired through IMxGatewayCliClient and the
adapter.

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

clients/dotnet/MxGateway.Client.Cli/IMxGatewayCliClient.cs

@@ -51,6 +51,27 @@ public interface IMxGatewayCliClient : IAsyncDisposable
         StreamEventsRequest request,
         CancellationToken cancellationToken);
 
+    /// <summary>
+    /// Acknowledges an active MXAccess alarm condition through the gateway.
+    /// </summary>
+    /// <param name="request">The acknowledge request — alarm reference, comment, operator user.</param>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>The acknowledge reply with protocol + native MxStatus.</returns>
+    Task<AcknowledgeAlarmReply> AcknowledgeAlarmAsync(
+        AcknowledgeAlarmRequest request,
+        CancellationToken cancellationToken);
+
+    /// <summary>
+    /// Attaches to the gateway's central alarm feed — the current active-alarm
+    /// snapshot followed by live transitions.
+    /// </summary>
+    /// <param name="request">The stream request, optionally scoped by alarm-reference prefix.</param>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>An async enumerable of alarm feed messages.</returns>
+    IAsyncEnumerable<AlarmFeedMessage> StreamAlarmsAsync(
+        StreamAlarmsRequest request,
+        CancellationToken cancellationToken);
+
     /// <summary>
     /// Tests connection to the Galaxy Repository.
     /// </summary>