docs: add missing XML doc comments across gateway, worker, and .NET client

Resolves 1113 documentation-completeness gaps flagged by CommentChecker
(MissingReturns, MissingInheritDoc, InheritDocMisused, MissingDoc,
MissingParam, RedundantInheritDoc) so the API surface is fully documented
and the analyzer scan is clean. Doc comments only; no code changes.

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

@@ -15,6 +15,7 @@ internal interface IGalaxyRepositoryClientTransport
     /// <summary>Tests the connection to the Galaxy Repository server.</summary>
     /// <param name="request">The test connection request.</param>
     /// <param name="callOptions">gRPC call options (timeout, cancellation, etc.).</param>
+    /// <returns>A task that resolves to the test connection reply.</returns>
     Task<TestConnectionReply> TestConnectionAsync(
         TestConnectionRequest request,
         CallOptions callOptions);
@@ -22,6 +23,7 @@ internal interface IGalaxyRepositoryClientTransport
     /// <summary>Gets the last deploy time from the Galaxy Repository server.</summary>
     /// <param name="request">The get last deploy time request.</param>
     /// <param name="callOptions">gRPC call options (timeout, cancellation, etc.).</param>
+    /// <returns>A task that resolves to the last deploy time reply.</returns>
     Task<GetLastDeployTimeReply> GetLastDeployTimeAsync(
         GetLastDeployTimeRequest request,
         CallOptions callOptions);
@@ -29,6 +31,7 @@ internal interface IGalaxyRepositoryClientTransport
     /// <summary>Discovers the object hierarchy in the Galaxy Repository.</summary>
     /// <param name="request">The discover hierarchy request.</param>
     /// <param name="callOptions">gRPC call options (timeout, cancellation, etc.).</param>
+    /// <returns>A task that resolves to the hierarchy discovery reply.</returns>
     Task<DiscoverHierarchyReply> DiscoverHierarchyAsync(
         DiscoverHierarchyRequest request,
         CallOptions callOptions);
@@ -36,6 +39,7 @@ internal interface IGalaxyRepositoryClientTransport
     /// <summary>Returns direct children of a parent in the Galaxy hierarchy.</summary>
     /// <param name="request">The browse children request.</param>
     /// <param name="callOptions">gRPC call options (timeout, cancellation, etc.).</param>
+    /// <returns>A task that resolves to the browse children reply.</returns>
     Task<BrowseChildrenReply> BrowseChildrenAsync(
         BrowseChildrenRequest request,
         CallOptions callOptions);
@@ -43,6 +47,7 @@ internal interface IGalaxyRepositoryClientTransport
     /// <summary>Watches for deployment events from the Galaxy Repository server.</summary>
     /// <param name="request">The watch deploy events request.</param>
     /// <param name="callOptions">gRPC call options (timeout, cancellation, etc.).</param>
+    /// <returns>An async enumerable of deploy events.</returns>
     IAsyncEnumerable<DeployEvent> WatchDeployEventsAsync(
         WatchDeployEventsRequest request,
         CallOptions callOptions);