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.

tests/Server/ZB.MOM.WW.OtOpcUa.OpcUaServer.Tests/OpcUaApplicationHostSecurityTests.cs

@@ -20,6 +20,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         Path.GetTempPath(),
         $"otopcua-pki-{Guid.NewGuid():N}");
 
+    /// <summary>
+    /// Verifies that BuildSecurityPolicies emits all three baseline security profiles.
+    /// </summary>
     [Fact]
     public void BuildSecurityPolicies_default_set_emits_all_three_baseline_profiles()
     {
@@ -39,6 +42,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         policies[2].SecurityPolicyUri.ShouldBe(SecurityPolicies.Basic256Sha256);
     }
 
+    /// <summary>
+    /// Verifies that BuildSecurityPolicies deduplicates repeated profiles.
+    /// </summary>
     [Fact]
     public void BuildSecurityPolicies_dedupes_repeated_profiles()
     {
@@ -54,6 +60,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         policies[1].SecurityMode.ShouldBe(MessageSecurityMode.None);
     }
 
+    /// <summary>
+    /// Verifies that BuildSecurityPolicies falls back to None when given empty input.
+    /// </summary>
     [Fact]
     public void BuildSecurityPolicies_empty_input_falls_back_to_none()
     {
@@ -64,6 +73,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         policies[0].SecurityPolicyUri.ShouldBe(SecurityPolicies.None);
     }
 
+    /// <summary>
+    /// Verifies that BuildUserTokenPolicies emits anonymous and username policies.
+    /// </summary>
     [Fact]
     public void BuildUserTokenPolicies_emits_anonymous_and_username()
     {
@@ -76,6 +88,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         userName.SecurityPolicyUri.ShouldBe(SecurityPolicies.Basic256Sha256);
     }
 
+    /// <summary>
+    /// Verifies that StartAsync populates ServerConfiguration with all enabled security profiles.
+    /// </summary>
     [Fact]
     public async Task StartAsync_populates_ServerConfiguration_with_all_enabled_profiles()
     {
@@ -111,6 +126,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         modes.ShouldBe(new[] { MessageSecurityMode.None, MessageSecurityMode.Sign, MessageSecurityMode.SignAndEncrypt });
     }
 
+    /// <summary>
+    /// Verifies that StartAsync with only SignAndEncrypt omits the None endpoint.
+    /// </summary>
     [Fact]
     public async Task StartAsync_with_only_signandencrypt_omits_None_endpoint()
     {
@@ -146,6 +164,9 @@ public sealed class OpcUaApplicationHostSecurityTests : IDisposable
         return port;
     }
 
+    /// <summary>
+    /// Cleans up temporary PKI files.
+    /// </summary>
     public void Dispose()
     {
         if (Directory.Exists(_pkiRoot))