feat: add CLI debug snapshot command for one-shot instance state inspection

Adds `debug snapshot --id <int>` to query a running instance's current
attribute values and alarm states without the subscribe/stream overhead
of the debug view. Routes through ManagementActor → CommunicationService
→ site DeploymentManager → InstanceActor using the existing remote query
pattern.

src/ScadaLink.Commons/Messages/DebugView/DebugSnapshotRequest.cs

@@ -0,0 +1,5 @@
+namespace ScadaLink.Commons.Messages.DebugView;
+
+public record DebugSnapshotRequest(
+    string InstanceUniqueName,
+    string CorrelationId);