docs: backfill XML documentation across 756 files

Adds <summary>, <param>, <typeparam>, and <inheritdoc/> tags to public
members surfaced by commentchecker — resolves 5,847 of 5,869 issues
(99.6%) across three /fixdocs passes.

src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Clients/FleetDiagnosticsClient.cs

@@ -22,12 +22,19 @@ public sealed class FleetDiagnosticsClient : IFleetDiagnosticsClient
     private readonly ActorSystem _system;
     private readonly string _systemName;
 
+    /// <summary>Initializes a new FleetDiagnosticsClient with the given actor system and cluster options.</summary>
+    /// <param name="system">The Akka actor system.</param>
+    /// <param name="options">Cluster configuration options.</param>
     public FleetDiagnosticsClient(ActorSystem system, IOptions<AkkaClusterOptions> options)
     {
         _system = system;
         _systemName = options.Value.SystemName;
     }
 
+    /// <summary>Gets diagnostics for a cluster node.</summary>
+    /// <param name="nodeId">The node identifier to query.</param>
+    /// <param name="ct">Cancellation token.</param>
+    /// <returns>Diagnostics snapshot for the node, or an empty snapshot if the query fails.</returns>
     public async Task<NodeDiagnosticsSnapshot> GetDiagnosticsAsync(NodeId nodeId, CancellationToken ct)
     {
         var selection = _system.ActorSelection($"akka.tcp://{_systemName}@{nodeId.Value}/user/driver-host");