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/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/ClientStoragePathsTests.cs

@@ -7,6 +7,7 @@ namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests;
 [Trait("Category", "Unit")]
 public sealed class ClientStoragePathsTests
 {
+    /// <summary>Verifies that GetRoot returns the canonical folder name under LocalAppData.</summary>
     [Fact]
     public void GetRoot_ReturnsCanonicalFolderName_UnderLocalAppData()
     {
@@ -15,6 +16,7 @@ public sealed class ClientStoragePathsTests
         root.ShouldContain(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData));
     }
 
+    /// <summary>Verifies that GetPkiPath nests PKI under root.</summary>
     [Fact]
     public void GetPkiPath_NestsPkiUnderRoot()
     {
@@ -22,12 +24,14 @@ public sealed class ClientStoragePathsTests
         pki.ShouldEndWith(Path.Combine(ClientStoragePaths.CanonicalFolderName, "pki"));
     }
 
+    /// <summary>Verifies that CanonicalFolderName is OtOpcUaClient.</summary>
     [Fact]
     public void CanonicalFolderName_IsOtOpcUaClient()
     {
         ClientStoragePaths.CanonicalFolderName.ShouldBe("OtOpcUaClient");
     }
 
+    /// <summary>Verifies that LegacyFolderName is LmxOpcUaClient.</summary>
     [Fact]
     public void LegacyFolderName_IsLmxOpcUaClient()
     {
@@ -36,6 +40,7 @@ public sealed class ClientStoragePathsTests
         ClientStoragePaths.LegacyFolderName.ShouldBe("LmxOpcUaClient");
     }
 
+    /// <summary>Verifies that TryRunLegacyMigration returns false on repeat invocation.</summary>
     [Fact]
     public void TryRunLegacyMigration_Returns_False_On_Repeat_Invocation()
     {