fix(client/dotnet): restore warnings-as-errors floor; license metadata; LazyBrowseNode publication (Client.Dotnet-022..025)

clients/dotnet/ZB.MOM.WW.MxGateway.Client/LazyBrowseNode.cs

@@ -12,9 +12,14 @@ public sealed class LazyBrowseNode
 {
     private readonly GalaxyRepositoryClient _client;
     private readonly BrowseChildrenOptions _options;
-    private readonly List<LazyBrowseNode> _children = [];
     private readonly SemaphoreSlim _expandLock = new(1, 1);
-    private bool _isExpanded;
+
+    // Published once, under _expandLock, when expansion completes. Lock-free readers
+    // see either the empty pre-expansion snapshot or the fully-populated post-expansion
+    // snapshot — never a partially-filled list — because the snapshot is built in a local
+    // and handed off via Volatile.Write (release) paired with Volatile.Read (acquire).
+    private IReadOnlyList<LazyBrowseNode> _children = [];
+    private volatile bool _isExpanded;
 
     internal LazyBrowseNode(
         GalaxyRepositoryClient client,
@@ -35,7 +40,7 @@ public sealed class LazyBrowseNode
     public bool HasChildrenHint { get; }
 
     /// <summary>Direct children loaded by <see cref="ExpandAsync"/>; empty until then.</summary>
-    public IReadOnlyList<LazyBrowseNode> Children => _children;
+    public IReadOnlyList<LazyBrowseNode> Children => Volatile.Read(ref _children);
 
     /// <summary>True after the first <see cref="ExpandAsync"/> call completes.</summary>
     public bool IsExpanded => _isExpanded;
@@ -46,7 +51,13 @@ public sealed class LazyBrowseNode
     /// </summary>
     /// <remarks>
     ///     Thread-safe: concurrent callers see exactly one fetch; subsequent callers
-    ///     (after the first completes) return immediately.
+    ///     (after the first completes) return immediately. <see cref="Children"/> and
+    ///     <see cref="IsExpanded"/> may be read concurrently with an in-flight
+    ///     <see cref="ExpandAsync"/> on another thread; the populated children are
+    ///     published as an immutable snapshot under a release barrier, so a reader that
+    ///     observes <see cref="IsExpanded"/> as <see langword="true"/> always sees the
+    ///     fully-populated <see cref="Children"/>, and a reader never enumerates a
+    ///     partially-built list.
     /// </remarks>
     /// <param name="cancellationToken">Token to observe for cancellation.</param>
     public async Task ExpandAsync(CancellationToken cancellationToken = default)
@@ -64,6 +75,10 @@ public sealed class LazyBrowseNode
                 return;
             }
 
+            // Accumulate into a local list, never the published field, so a lock-free
+            // reader can never observe a half-populated collection or enumerate a list
+            // that is being mutated mid-append.
+            List<LazyBrowseNode> children = [];
             string pageToken = string.Empty;
             HashSet<string> seenPageTokens = new(StringComparer.Ordinal);
             do
@@ -79,7 +94,7 @@ public sealed class LazyBrowseNode
                 for (int i = 0; i < reply.Children.Count; i++)
                 {
                     bool hint = i < reply.ChildHasChildren.Count && reply.ChildHasChildren[i];
-                    _children.Add(new LazyBrowseNode(_client, reply.Children[i], hint, _options));
+                    children.Add(new LazyBrowseNode(_client, reply.Children[i], hint, _options));
                 }
 
                 pageToken = reply.NextPageToken;
@@ -91,6 +106,10 @@ public sealed class LazyBrowseNode
             }
             while (!string.IsNullOrWhiteSpace(pageToken));
 
+            // Publish the completed, immutable snapshot (release) before marking the node
+            // expanded (the volatile write below). A reader that observes IsExpanded == true
+            // is guaranteed to also observe the fully-populated Children.
+            Volatile.Write(ref _children, children);
             _isExpanded = true;
         }
         finally

clients/dotnet/ZB.MOM.WW.MxGateway.Client/ZB.MOM.WW.MxGateway.Client.csproj

@@ -21,10 +21,15 @@
     <PackageId>ZB.MOM.WW.MxGateway.Client</PackageId>
     <Description>.NET 10 gRPC client for the MxAccessGateway service. Provides typed wrappers, retry, and a lazy-browse walker over the Galaxy Repository hierarchy.</Description>
     <PackageReadmeFile>README.md</PackageReadmeFile>
+    <!-- Only the shipped library generates XML docs (matching src/Contracts). The Cli and
+         Tests projects are not packable and do not document their public surface, so this
+         stays out of the shared Directory.Build.props to avoid CS1591 on test classes. -->
+    <GenerateDocumentationFile>true</GenerateDocumentationFile>
   </PropertyGroup>
 
   <ItemGroup>
     <None Include="..\README.md" Pack="true" PackagePath="\" />
+    <None Include="..\LICENSE.txt" Pack="true" PackagePath="\" />
   </ItemGroup>
 
   <ItemGroup>