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.

src/Core/ZB.MOM.WW.OtOpcUa.Commons/OpcUa/DeferredAddressSpaceSink.cs

@@ -18,20 +18,41 @@ public sealed class DeferredAddressSpaceSink : IOpcUaAddressSpaceSink
 
     /// <summary>Swap in the production sink. Pass <c>null</c> to revert to the null sink
     /// (used during graceful shutdown so post-stop writes don't hit a half-disposed manager).</summary>
+    /// <param name="sink">The sink implementation to use, or null to use the null sink.</param>
     public void SetSink(IOpcUaAddressSpaceSink? sink) =>
         _inner = sink ?? NullOpcUaAddressSpaceSink.Instance;
 
+    /// <summary>Writes a value to the OPC UA address space through the inner sink.</summary>
+    /// <param name="nodeId">The node ID of the variable.</param>
+    /// <param name="value">The value to write.</param>
+    /// <param name="quality">The OPC UA quality value.</param>
+    /// <param name="sourceTimestampUtc">The source timestamp in UTC.</param>
     public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime sourceTimestampUtc)
         => _inner.WriteValue(nodeId, value, quality, sourceTimestampUtc);
 
+    /// <summary>Writes an alarm state through the inner sink.</summary>
+    /// <param name="alarmNodeId">The node ID of the alarm condition.</param>
+    /// <param name="active">Whether the alarm is active.</param>
+    /// <param name="acknowledged">Whether the alarm has been acknowledged.</param>
+    /// <param name="sourceTimestampUtc">The source timestamp in UTC.</param>
     public void WriteAlarmState(string alarmNodeId, bool active, bool acknowledged, DateTime sourceTimestampUtc)
         => _inner.WriteAlarmState(alarmNodeId, active, acknowledged, sourceTimestampUtc);
 
+    /// <summary>Ensures a folder exists in the address space through the inner sink.</summary>
+    /// <param name="folderNodeId">The node ID of the folder.</param>
+    /// <param name="parentNodeId">The node ID of the parent folder, or null for root.</param>
+    /// <param name="displayName">The display name of the folder.</param>
     public void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName)
         => _inner.EnsureFolder(folderNodeId, parentNodeId, displayName);
 
+    /// <summary>Ensures a variable exists in the address space through the inner sink.</summary>
+    /// <param name="variableNodeId">The node ID of the variable.</param>
+    /// <param name="parentFolderNodeId">The node ID of the parent folder, or null for root.</param>
+    /// <param name="displayName">The display name of the variable.</param>
+    /// <param name="dataType">The OPC UA data type of the variable.</param>
     public void EnsureVariable(string variableNodeId, string? parentFolderNodeId, string displayName, string dataType)
         => _inner.EnsureVariable(variableNodeId, parentFolderNodeId, displayName, dataType);
 
+    /// <summary>Rebuilds the address space through the inner sink.</summary>
     public void RebuildAddressSpace() => _inner.RebuildAddressSpace();
 }

src/Core/ZB.MOM.WW.OtOpcUa.Commons/OpcUa/DeferredServiceLevelPublisher.cs

@@ -12,8 +12,11 @@ public sealed class DeferredServiceLevelPublisher : IServiceLevelPublisher
     private volatile IServiceLevelPublisher _inner = NullServiceLevelPublisher.Instance;
 
     /// <summary>Swap the underlying publisher. Pass null to revert to the Null no-op.</summary>
+    /// <param name="inner">The publisher implementation to use, or null to use the null publisher.</param>
     public void SetInner(IServiceLevelPublisher? inner) =>
         _inner = inner ?? NullServiceLevelPublisher.Instance;
 
+    /// <summary>Publishes a service level value to the inner publisher.</summary>
+    /// <param name="serviceLevel">The service level to publish.</param>
     public void Publish(byte serviceLevel) => _inner.Publish(serviceLevel);
 }

src/Core/ZB.MOM.WW.OtOpcUa.Commons/OpcUa/IOpcUaAddressSpaceSink.cs

@@ -9,9 +9,17 @@ namespace ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
 public interface IOpcUaAddressSpaceSink
 {
     /// <summary>Write a Variable node's current value + quality + source timestamp.</summary>
+    /// <param name="nodeId">The OPC UA node ID of the variable.</param>
+    /// <param name="value">The value to write.</param>
+    /// <param name="quality">The quality status of the value.</param>
+    /// <param name="sourceTimestampUtc">The source timestamp in UTC.</param>
     void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime sourceTimestampUtc);
 
     /// <summary>Write an alarm-condition Variable's active/acknowledged state.</summary>
+    /// <param name="alarmNodeId">The OPC UA node ID of the alarm.</param>
+    /// <param name="active">Whether the alarm is active.</param>
+    /// <param name="acknowledged">Whether the alarm has been acknowledged.</param>
+    /// <param name="sourceTimestampUtc">The source timestamp in UTC.</param>
     void WriteAlarmState(string alarmNodeId, bool active, bool acknowledged, DateTime sourceTimestampUtc);
 
     /// <summary>
@@ -20,6 +28,9 @@ public interface IOpcUaAddressSpaceSink
     ///     <paramref name="parentNodeId"/> is null the folder is parented under the namespace
     ///     root. Idempotent: calling twice with the same id is safe.
     /// </summary>
+    /// <param name="folderNodeId">The OPC UA node ID for the folder.</param>
+    /// <param name="parentNodeId">The parent folder node ID, or null for namespace root.</param>
+    /// <param name="displayName">The display name for the folder.</param>
     void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName);
 
     /// <summary>
@@ -29,6 +40,9 @@ public interface IOpcUaAddressSpaceSink
     ///     Used by <c>Phase7Applier</c> to materialise Galaxy / SystemPlatform tags ahead of any
     ///     driver-side subscribe so OPC UA clients can browse them. Idempotent.
     /// </summary>
+    /// <param name="variableNodeId">The OPC UA node ID for the variable.</param>
+    /// <param name="parentFolderNodeId">The parent folder node ID, or null for namespace root.</param>
+    /// <param name="displayName">The display name for the variable.</param>
     /// <param name="dataType">OPC UA built-in type name ("Boolean" / "Int32" / "Float" / etc.).</param>
     void EnsureVariable(string variableNodeId, string? parentFolderNodeId, string displayName, string dataType);
 
@@ -49,9 +63,19 @@ public sealed class NullOpcUaAddressSpaceSink : IOpcUaAddressSpaceSink
 {
     public static readonly NullOpcUaAddressSpaceSink Instance = new();
     private NullOpcUaAddressSpaceSink() { }
+
+    /// <inheritdoc />
     public void WriteValue(string nodeId, object? value, OpcUaQuality quality, DateTime sourceTimestampUtc) { }
+
+    /// <inheritdoc />
     public void WriteAlarmState(string alarmNodeId, bool active, bool acknowledged, DateTime sourceTimestampUtc) { }
+
+    /// <inheritdoc />
     public void EnsureFolder(string folderNodeId, string? parentNodeId, string displayName) { }
+
+    /// <inheritdoc />
     public void EnsureVariable(string variableNodeId, string? parentFolderNodeId, string displayName, string dataType) { }
+
+    /// <inheritdoc />
     public void RebuildAddressSpace() { }
 }

src/Core/ZB.MOM.WW.OtOpcUa.Commons/OpcUa/IServiceLevelPublisher.cs

@@ -8,6 +8,8 @@ namespace ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
 /// </summary>
 public interface IServiceLevelPublisher
 {
+    /// <summary>Publishes the service level value to the OPC UA Server object.</summary>
+    /// <param name="serviceLevel">The service level value (0-255).</param>
     void Publish(byte serviceLevel);
 }
 
@@ -17,6 +19,11 @@ public sealed class NullServiceLevelPublisher : IServiceLevelPublisher
 {
     public static readonly NullServiceLevelPublisher Instance = new();
     private NullServiceLevelPublisher() { }
+
+    /// <summary>Gets the last published service level value.</summary>
     public byte LastPublished { get; private set; }
+
+    /// <summary>Records the service level value without publishing.</summary>
+    /// <param name="serviceLevel">The service level value (0-255).</param>
     public void Publish(byte serviceLevel) => LastPublished = serviceLevel;
 }