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/Interfaces/IAdminOperationsClient.cs

@@ -9,5 +9,9 @@ namespace ZB.MOM.WW.OtOpcUa.Commons.Interfaces;
 /// </summary>
 public interface IAdminOperationsClient
 {
+    /// <summary>Starts a new deployment on the cluster-singleton admin operations actor.</summary>
+    /// <param name="createdBy">The user or system identifier triggering the deployment.</param>
+    /// <param name="ct">The cancellation token.</param>
+    /// <returns>A task representing the asynchronous operation containing the deployment start result.</returns>
     Task<StartDeploymentResult> StartDeploymentAsync(string createdBy, CancellationToken ct);
 }

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Interfaces/IClusterRoleInfo.cs

@@ -10,11 +10,23 @@ namespace ZB.MOM.WW.OtOpcUa.Commons.Interfaces;
 /// </summary>
 public interface IClusterRoleInfo
 {
+    /// <summary>Gets the local cluster node identifier.</summary>
     NodeId LocalNode { get; }
+    /// <summary>Gets the set of roles assigned to the local node.</summary>
     IReadOnlySet<string> LocalRoles { get; }
+    /// <summary>Checks if the local node has the specified role.</summary>
+    /// <param name="role">Role name to check.</param>
+    /// <returns>True if the local node has the role; otherwise, false.</returns>
     bool HasRole(string role);
+    /// <summary>Gets all nodes assigned to the specified role.</summary>
+    /// <param name="role">Role name to query.</param>
+    /// <returns>List of node identifiers with the role.</returns>
     IReadOnlyList<NodeId> MembersWithRole(string role);
+    /// <summary>Gets the leader node for the specified role, or null if no leader is elected.</summary>
+    /// <param name="role">Role name to query.</param>
+    /// <returns>The leader node identifier, or null if no leader exists.</returns>
     NodeId? RoleLeader(string role);
 
+    /// <summary>Occurs when the leader of a role changes.</summary>
     event EventHandler<RoleLeaderChangedEventArgs>? RoleLeaderChanged;
 }

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Interfaces/IFleetDiagnosticsClient.cs

@@ -8,5 +8,8 @@ namespace ZB.MOM.WW.OtOpcUa.Commons.Interfaces;
 /// </summary>
 public interface IFleetDiagnosticsClient
 {
+    /// <summary>Gets diagnostics for the specified node.</summary>
+    /// <param name="nodeId">The node ID to retrieve diagnostics for.</param>
+    /// <param name="ct">The cancellation token.</param>
     Task<NodeDiagnosticsSnapshot> GetDiagnosticsAsync(NodeId nodeId, CancellationToken ct);
 }

src/Core/ZB.MOM.WW.OtOpcUa.Commons/Interfaces/RoleLeaderChangedEventArgs.cs

@@ -2,9 +2,15 @@ using ZB.MOM.WW.OtOpcUa.Commons.Types;
 
 namespace ZB.MOM.WW.OtOpcUa.Commons.Interfaces;
 
+/// <summary>Event arguments for role leader change notifications.</summary>
 public sealed class RoleLeaderChangedEventArgs : EventArgs
 {
+    /// <summary>Gets the role name that changed leadership.</summary>
     public required string Role { get; init; }
+
+    /// <summary>Gets the previous leader node ID, or null if there was no previous leader.</summary>
     public required NodeId? PreviousLeader { get; init; }
+
+    /// <summary>Gets the new leader node ID, or null if the role is now leaderless.</summary>
     public required NodeId? NewLeader { get; init; }
 }