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.OpcUaServer/OpcUaApplicationHost.cs

@@ -22,10 +22,16 @@ public enum OpcUaSecurityProfile
     Basic256Sha256SignAndEncrypt,
 }
 
+/// <summary>Configuration options for OPC UA application hosting.</summary>
 public sealed class OpcUaApplicationHostOptions
 {
+    /// <summary>Gets or sets the application name (default "OtOpcUa").</summary>
     public string ApplicationName { get; set; } = "OtOpcUa";
+
+    /// <summary>Gets or sets the application URI (default "urn:OtOpcUa").</summary>
     public string ApplicationUri { get; set; } = "urn:OtOpcUa";
+
+    /// <summary>Gets or sets the product URI (default "https://zb.com/otopcua").</summary>
     public string ProductUri { get; set; } = "https://zb.com/otopcua";
 
     /// <summary>Listening port for the binary endpoint (default 4840).</summary>
@@ -93,6 +99,10 @@ public sealed class OpcUaApplicationHost : IAsyncDisposable
     private StandardServer? _server;
     private ImpersonateEventHandler? _impersonateHandler;
 
+    /// <summary>Initializes a new instance of the OPC UA application host.</summary>
+    /// <param name="options">The host configuration options.</param>
+    /// <param name="logger">The logger for diagnostic output.</param>
+    /// <param name="userAuthenticator">An optional user authenticator for UserName tokens; uses null implementation if not provided.</param>
     public OpcUaApplicationHost(
         OpcUaApplicationHostOptions options,
         ILogger<OpcUaApplicationHost> logger,
@@ -103,9 +113,15 @@ public sealed class OpcUaApplicationHost : IAsyncDisposable
         _userAuthenticator = userAuthenticator ?? NullOpcUaUserAuthenticator.Instance;
     }
 
+    /// <summary>Gets the OPC Foundation application instance, or null if not yet started.</summary>
     public ApplicationInstance? ApplicationInstance => _application;
+
+    /// <summary>Gets the OPC UA server instance, or null if not yet started.</summary>
     public StandardServer? Server => _server;
 
+    /// <summary>Starts the OPC UA application and server.</summary>
+    /// <param name="server">The standard server instance to start.</param>
+    /// <param name="cancellationToken">A cancellation token for the operation.</param>
     public async Task StartAsync(StandardServer server, CancellationToken cancellationToken)
     {
         _server = server;
@@ -215,6 +231,9 @@ public sealed class OpcUaApplicationHost : IAsyncDisposable
     /// the full SDK. Side-effects are confined to mutating <see cref="ImpersonateEventArgs"/>
     /// and logging.
     /// </summary>
+    /// <param name="authenticator">The user authenticator to validate credentials.</param>
+    /// <param name="args">The impersonation event arguments to process.</param>
+    /// <param name="logger">The logger for diagnostic output.</param>
     internal static void HandleImpersonation(
         IOpcUaUserAuthenticator authenticator,
         ImpersonateEventArgs args,
@@ -351,6 +370,7 @@ public sealed class OpcUaApplicationHost : IAsyncDisposable
     /// falls back to a single None entry so the server doesn't refuse to start with no
     /// listening endpoints — the misconfiguration is logged and very visible.
     /// </summary>
+    /// <param name="profiles">The security profiles to build policies for.</param>
     internal static IEnumerable<ServerSecurityPolicy> BuildSecurityPolicies(IEnumerable<OpcUaSecurityProfile> profiles)
     {
         var seen = new HashSet<OpcUaSecurityProfile>();
@@ -409,6 +429,7 @@ public sealed class OpcUaApplicationHost : IAsyncDisposable
         };
     }
 
+    /// <summary>Disposes the application host and cleans up resources.</summary>
     public ValueTask DisposeAsync()
     {
         if (_impersonateHandler is not null && _server?.CurrentInstance?.SessionManager is { } sessionManager)