docs: complete XML-doc coverage and strip internal tracking IDs from code comments

Resolve all CommentChecker findings across the gateway server, worker, tests,
and .NET client (314 -> 0 real issues): add missing <returns>/<summary>/<param>
on public and test members, convert Stream/interface overrides to <inheritdoc/>,
and remove internal task/issue tracking IDs (SEC-*, IPC-*, WRK-*, GWC-*, TST-*,
Client.Dotnet-*) from shipped code documentation while preserving the design
rationale prose. Shipped comments should not carry internal bookkeeping, and
complete XML docs keep the analyzer/TreatWarningsAsErrors gate and generated API
docs clean. The 6 remaining flags are heuristic false positives (MD5, UTC-4,
capacity-1, near-1601) left intact so real documentation is not corrupted.

Claude-Session: https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW

clients/dotnet/ZB.MOM.WW.MxGateway.Client.Tests/LazyBrowseNodeTests.cs

@@ -12,6 +12,7 @@ public sealed class LazyBrowseNodeTests
     /// Verifies that calling BrowseAsync with no parent returns the root nodes
     /// from the first BrowseChildren reply and surfaces the per-child has-children hint.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Browse_NoParent_ReturnsRoots()
     {
@@ -36,6 +37,7 @@ public sealed class LazyBrowseNodeTests
     /// <summary>
     /// Verifies that ExpandAsync populates Children and marks the node expanded after one RPC.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Expand_PopulatesChildrenAndMarksExpanded()
     {
@@ -62,6 +64,7 @@ public sealed class LazyBrowseNodeTests
     /// <summary>
     /// Verifies that a second ExpandAsync call is a no-op and issues no additional RPC.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Expand_CalledTwice_NoSecondRpc()
     {
@@ -86,6 +89,7 @@ public sealed class LazyBrowseNodeTests
     /// <summary>
     /// Verifies that an RPC failure (NotFound) during expand is wrapped in MxGatewayException.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Expand_UnknownParent_ThrowsMxGatewayException()
     {
@@ -113,6 +117,7 @@ public sealed class LazyBrowseNodeTests
     /// <summary>
     /// Verifies that ExpandAsync drains multi-page sibling replies and forwards the page token.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Expand_MultiPageSiblings_GathersAllPages()
     {
@@ -147,6 +152,7 @@ public sealed class LazyBrowseNodeTests
     /// <summary>
     /// Verifies that ten concurrent ExpandAsync calls issue exactly one RPC, not ten.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Expand_CalledConcurrently_OnlyFiresOneRpc()
     {
@@ -179,8 +185,9 @@ public sealed class LazyBrowseNodeTests
     /// Verifies that reading Children/IsExpanded concurrently with an in-flight ExpandAsync
     /// never throws (no torn enumeration of a mid-append list) and, once IsExpanded flips to
     /// true, the published Children snapshot is fully populated. Pins the safe-publication
-    /// contract on the lock-free readers (Client.Dotnet-025).
+    /// contract on the lock-free readers.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Expand_ConcurrentReadOfChildren_NeverTearsAndPublishesAtomically()
     {
@@ -268,6 +275,7 @@ public sealed class LazyBrowseNodeTests
     /// <summary>
     /// Verifies that BrowseChildrenOptions filter fields are forwarded to the BrowseChildren request.
     /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Browse_WithFilter_ForwardsToRequest()
     {