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.Abstractions.Tests/Historian/IHistorianDataSourceContractTests.cs

@@ -11,6 +11,7 @@ namespace ZB.MOM.WW.OtOpcUa.Core.Abstractions.Tests.Historian;
 /// </summary>
 public sealed class IHistorianDataSourceContractTests
 {
+    /// <summary>Verifies that the interface lives in the root namespace.</summary>
     [Fact]
     public void Interface_LivesInRootNamespace()
     {
@@ -18,6 +19,7 @@ public sealed class IHistorianDataSourceContractTests
             .ShouldBe("ZB.MOM.WW.OtOpcUa.Core.Abstractions");
     }
 
+    /// <summary>Verifies that the interface is public.</summary>
     [Fact]
     public void Interface_IsPublic()
     {
@@ -25,6 +27,7 @@ public sealed class IHistorianDataSourceContractTests
         typeof(IHistorianDataSource).IsInterface.ShouldBeTrue();
     }
 
+    /// <summary>Verifies that the interface extends IDisposable.</summary>
     [Fact]
     public void Interface_ExtendsIDisposable()
     {
@@ -32,6 +35,9 @@ public sealed class IHistorianDataSourceContractTests
             .ShouldBeTrue("data sources own backend connections; the server disposes them on shutdown");
     }
 
+    /// <summary>Verifies that read methods return the expected task shape.</summary>
+    /// <param name="methodName">The name of the interface method to inspect.</param>
+    /// <param name="expectedReturnType">The expected Task return type of the method.</param>
     [Theory]
     [InlineData("ReadRawAsync", typeof(Task<HistoryReadResult>))]
     [InlineData("ReadProcessedAsync", typeof(Task<HistoryReadResult>))]
@@ -44,6 +50,7 @@ public sealed class IHistorianDataSourceContractTests
         method!.ReturnType.ShouldBe(expectedReturnType);
     }
 
+    /// <summary>Verifies that GetHealthSnapshot is synchronous.</summary>
     [Fact]
     public void GetHealthSnapshot_IsSynchronous()
     {
@@ -52,6 +59,7 @@ public sealed class IHistorianDataSourceContractTests
         method!.ReturnType.ShouldBe(typeof(HistorianHealthSnapshot));
     }
 
+    /// <summary>Verifies that HealthSnapshot accepts an empty cluster node list.</summary>
     [Fact]
     public void HealthSnapshot_AcceptsEmptyClusterNodeList()
     {
@@ -72,6 +80,7 @@ public sealed class IHistorianDataSourceContractTests
         snapshot.Nodes.ShouldBeEmpty();
     }
 
+    /// <summary>Verifies that HealthSnapshot preserves cluster nodes.</summary>
     [Fact]
     public void HealthSnapshot_PreservesClusterNodes()
     {
@@ -101,6 +110,7 @@ public sealed class IHistorianDataSourceContractTests
         snapshot.Nodes[0].ShouldBe(node);
     }
 
+    /// <summary>Verifies that ClusterNodeState records are equal by value.</summary>
     [Fact]
     public void ClusterNodeState_RecordEqualityByValue()
     {
@@ -110,6 +120,7 @@ public sealed class IHistorianDataSourceContractTests
         a.ShouldBe(b);
     }
 
+    /// <summary>Verifies that ClusterNodeState instances are distinct by any field.</summary>
     [Fact]
     public void ClusterNodeState_DistinctByAnyField()
     {
@@ -127,6 +138,9 @@ public sealed class IHistorianDataSourceContractTests
     ///     (see <c>WonderwareHistorianClient</c> / <c>HistorianDataSource</c> usage). This test
     ///     pins both shapes so accidental changes are caught.
     /// </summary>
+    /// <param name="methodName">The name of the method to test.</param>
+    /// <param name="parameterName">The name of the parameter to verify.</param>
+    /// <param name="expectedType">The expected parameter type.</param>
     [Theory]
     [InlineData("ReadRawAsync", "maxValuesPerNode", typeof(uint))]
     [InlineData("ReadEventsAsync", "maxEvents", typeof(int))]
@@ -139,6 +153,10 @@ public sealed class IHistorianDataSourceContractTests
         parameter!.ParameterType.ShouldBe(expectedType);
     }
 
+    /// <summary>Verifies that history provider max parameters have the expected type.</summary>
+    /// <param name="methodName">The name of the method to test.</param>
+    /// <param name="parameterName">The name of the parameter to verify.</param>
+    /// <param name="expectedType">The expected parameter type.</param>
     [Theory]
     [InlineData("ReadRawAsync", "maxValuesPerNode", typeof(uint))]
     [InlineData("ReadEventsAsync", "maxEvents", typeof(int))]
@@ -159,6 +177,7 @@ public sealed class IHistorianDataSourceContractTests
     ///     historian must implement them). This test pins the asymmetry so an implementer cannot
     ///     accidentally collapse the two surfaces and so the documented rationale stays load-bearing.
     /// </summary>
+    /// <param name="methodName">The name of the optional method to check.</param>
     [Theory]
     [InlineData("ReadAtTimeAsync")]
     [InlineData("ReadEventsAsync")]