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.Core.Scripting.Tests/ScriptSandboxBuildTests.cs

@@ -14,12 +14,14 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Scripting.Tests;
 [Trait("Category", "Unit")]
 public sealed class ScriptSandboxBuildTests
 {
+    /// <summary>Verifies that a null context type throws ArgumentNullException.</summary>
     [Fact]
     public void Null_context_type_throws_ArgumentNullException()
     {
         Should.Throw<ArgumentNullException>(() => ScriptSandbox.Build(null!));
     }
 
+    /// <summary>Verifies that a non-ScriptContext type throws ArgumentException.</summary>
     [Fact]
     public void Non_ScriptContext_type_throws_ArgumentException()
     {
@@ -30,6 +32,7 @@ public sealed class ScriptSandboxBuildTests
               .ParamName.ShouldBe("contextType");
     }
 
+    /// <summary>Verifies that the abstract ScriptContext base type is accepted by the sandbox builder.</summary>
     [Fact]
     public void Abstract_ScriptContext_base_type_is_accepted()
     {
@@ -40,6 +43,7 @@ public sealed class ScriptSandboxBuildTests
         options.ShouldNotBeNull();
     }
 
+    /// <summary>Verifies that a concrete subclass is accepted and its assembly is referenced in the sandbox.</summary>
     [Fact]
     public void Concrete_subclass_is_accepted_and_its_assembly_referenced()
     {