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/Core/ZB.MOM.WW.OtOpcUa.Cluster.Tests/RoleParserTests.cs

@@ -5,6 +5,8 @@ namespace ZB.MOM.WW.OtOpcUa.Cluster.Tests;
 
 public sealed class RoleParserTests
 {
+    /// <summary>Verifies that empty input yields an empty array.</summary>
+    /// <param name="raw">The raw input string to test (null, empty, or whitespace).</param>
     [Theory]
     [InlineData(null)]
     [InlineData("")]
@@ -14,36 +16,42 @@ public sealed class RoleParserTests
         RoleParser.Parse(raw).ShouldBeEmpty();
     }
 
+    /// <summary>Verifies that a single role 'admin' is parsed correctly.</summary>
     [Fact]
     public void Single_role_admin()
     {
         RoleParser.Parse("admin").ShouldBe(new[] { "admin" });
     }
 
+    /// <summary>Verifies that two roles separated by comma are parsed correctly.</summary>
     [Fact]
     public void Two_roles_csv()
     {
         RoleParser.Parse("admin,driver").ShouldBe(new[] { "admin", "driver" });
     }
 
+    /// <summary>Verifies that parser tolerates surrounding whitespace.</summary>
     [Fact]
     public void Whitespace_tolerant()
     {
         RoleParser.Parse(" admin , driver ").ShouldBe(new[] { "admin", "driver" });
     }
 
+    /// <summary>Verifies that parser is case-insensitive and normalizes to lowercase.</summary>
     [Fact]
     public void Case_insensitive_normalizes_to_lower()
     {
         RoleParser.Parse("ADMIN,Driver").ShouldBe(new[] { "admin", "driver" });
     }
 
+    /// <summary>Verifies that duplicate roles are removed.</summary>
     [Fact]
     public void Duplicate_roles_deduped()
     {
         RoleParser.Parse("admin,admin,driver").ShouldBe(new[] { "admin", "driver" });
     }
 
+    /// <summary>Verifies that parser throws for unknown roles.</summary>
     [Fact]
     public void Unknown_role_throws()
     {