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.Security.Tests/RoleMapperTests.cs

@@ -6,6 +6,9 @@ namespace ZB.MOM.WW.OtOpcUa.Security.Tests;
 
 public sealed class RoleMapperTests
 {
+    /// <summary>
+    /// Verifies that empty mapping returns no roles.
+    /// </summary>
     [Fact]
     public void Empty_mapping_returns_empty()
     {
@@ -13,6 +16,9 @@ public sealed class RoleMapperTests
             .ShouldBeEmpty();
     }
 
+    /// <summary>
+    /// Verifies that RoleMapper maps a group to its corresponding role.
+    /// </summary>
     [Fact]
     public void Maps_group_to_role()
     {
@@ -22,6 +28,9 @@ public sealed class RoleMapperTests
             .ShouldBe(new[] { "FleetAdmin" });
     }
 
+    /// <summary>
+    /// Verifies that group matching is case-insensitive.
+    /// </summary>
     [Fact]
     public void Case_insensitive_group_match()
     {
@@ -34,6 +43,9 @@ public sealed class RoleMapperTests
             .ShouldBe(new[] { "FleetAdmin" });
     }
 
+    /// <summary>
+    /// Verifies that multiple groups are deduplicated to unique roles.
+    /// </summary>
     [Fact]
     public void Multiple_groups_dedup_roles()
     {