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.Runtime.Tests/OpcUa/OpcUaPublishActorRebuildTests.cs

@@ -18,6 +18,7 @@ namespace ZB.MOM.WW.OtOpcUa.Runtime.Tests.OpcUa;
 
 public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 {
+    /// <summary>Tests that RebuildAddressSpace with dbFactory loads artifact, composes, and applies.</summary>
     [Fact]
     public void RebuildAddressSpace_with_dbFactory_loads_artifact_composes_and_applies()
     {
@@ -42,6 +43,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         }, duration: TimeSpan.FromSeconds(2));
     }
 
+    /// <summary>Tests that rebuild with no artifact is idempotent no-op.</summary>
     [Fact]
     public void Rebuild_with_no_artifact_is_idempotent_no_op()
     {
@@ -61,6 +63,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         sink.RebuildCalls.ShouldBe(0);
     }
 
+    /// <summary>Tests that second rebuild with same artifact is empty plan no-op.</summary>
     [Fact]
     public void Second_rebuild_with_same_artifact_is_empty_plan_no_op()
     {
@@ -81,6 +84,7 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
         sink.RebuildCalls.ShouldBe(1);
     }
 
+    /// <summary>Tests that rebuild without dbFactory falls back to raw sink rebuild.</summary>
     [Fact]
     public void Rebuild_without_dbFactory_falls_back_to_raw_sink_rebuild()
     {
@@ -133,14 +137,31 @@ public sealed class OpcUaPublishActorRebuildTests : RuntimeActorTestBase
 
     private sealed class RecordingSink : IOpcUaAddressSpaceSink
     {
+        /// <summary>Gets the list of recorded sink calls.</summary>
         public ConcurrentQueue<string> Calls { get; } = new();
+        /// <summary>Gets or sets the count of rebuild address space calls.</summary>
         public int RebuildCalls;
+        /// <summary>Records a value write call.</summary>
+        /// <param name="nodeId">The OPC UA node ID.</param>
+        /// <param name="value">The value to write.</param>
+        /// <param name="quality">The OPC UA quality code.</param>
+        /// <param name="ts">The timestamp of the write.</param>
         public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime ts)
             => Calls.Enqueue($"WV:{nodeId}");
+        /// <summary>Records an alarm state write call.</summary>
+        /// <param name="alarmNodeId">The alarm node ID.</param>
+        /// <param name="active">Whether the alarm is active.</param>
+        /// <param name="acknowledged">Whether the alarm is acknowledged.</param>
+        /// <param name="ts">The timestamp of the state change.</param>
         public void WriteAlarmState(string alarmNodeId, bool active, bool acknowledged, DateTime ts)
             => Calls.Enqueue($"WA:{alarmNodeId}");
+        /// <summary>Records a folder ensure call.</summary>
+        /// <param name="folderNodeId">The folder node ID.</param>
+        /// <param name="parentNodeId">The parent node ID, or null if this is a root folder.</param>
+        /// <param name="displayName">The display name of the folder.</param>
         public void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName)
             => Calls.Enqueue($"EF:{folderNodeId}");
+        /// <summary>Records a rebuild address space call.</summary>
         public void RebuildAddressSpace() => Interlocked.Increment(ref RebuildCalls);
     }
 }