deprecate(lmxproxy): move all LmxProxy code, tests, and docs to deprecated/

LmxProxy is no longer needed. Moved the entire lmxproxy/ workspace, DCL
adapter files, and related docs to deprecated/. Removed LmxProxy registration
from DataConnectionFactory, project reference from DCL, protocol option from
UI, and cleaned up all requirement docs.

deprecated/lmxproxy/src-reference/ZB.MOM.WW.LmxProxy.Host/Domain/ClientStats.cs

@@ -0,0 +1,23 @@
+namespace ZB.MOM.WW.LmxProxy.Host.Domain
+{
+    /// <summary>
+    ///     Per-client subscription statistics.
+    /// </summary>
+    public class ClientStats
+    {
+        /// <summary>
+        ///     Gets or sets the number of tags the client is subscribed to.
+        /// </summary>
+        public int SubscribedTags { get; set; }
+
+        /// <summary>
+        ///     Gets or sets the number of delivered messages.
+        /// </summary>
+        public long DeliveredMessages { get; set; }
+
+        /// <summary>
+        ///     Gets or sets the number of dropped messages.
+        /// </summary>
+        public long DroppedMessages { get; set; }
+    }
+}