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/MxGatewayClientSessionTests.cs

@@ -7,6 +7,7 @@ namespace ZB.MOM.WW.MxGateway.Client.Tests;
 public sealed class MxGatewayClientSessionTests
 {
     /// <summary>Verifies that open session attaches API key metadata and cancellation token.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task OpenSessionRawAsync_AttachesApiKeyMetadataAndCancellation()
     {
@@ -22,6 +23,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that open session returns a session with the raw open reply.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task OpenSessionAsync_ReturnsSessionWithRawOpenReply()
     {
@@ -37,6 +39,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that register builds a register command and returns server handle.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task RegisterAsync_BuildsRegisterCommandAndReturnsServerHandle()
     {
@@ -62,6 +65,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that add item 2 builds a command with the specified context.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task AddItem2Async_BuildsAddItem2CommandWithContext()
     {
@@ -87,6 +91,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that write raw builds a write command with the raw value.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task WriteRawAsync_BuildsWriteCommandWithRawValue()
     {
@@ -118,6 +123,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that write 2 raw builds a write 2 command with value and timestamp.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task Write2RawAsync_BuildsWrite2CommandWithValueAndTimestamp()
     {
@@ -146,6 +152,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that subscribe bulk builds one command and returns per-item results.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task SubscribeBulkAsync_BuildsOneBulkCommandAndReturnsPerItemResults()
     {
@@ -185,6 +192,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that stream events yields events in the order received from the gateway.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task StreamEventsAsync_YieldsEventsInGatewayOrder()
     {
@@ -216,6 +224,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that close is explicit and idempotent.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task CloseAsync_IsExplicitAndIdempotent()
     {
@@ -232,6 +241,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that invoke retries safe diagnostic commands on transient RPC failure.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task InvokeAsync_RetriesSafeDiagnosticCommandOnTransientGrpcFailure()
     {
@@ -256,6 +266,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that open session does not retry on transient RPC failure.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task OpenSessionAsync_DoesNotRetryTransientGrpcFailure()
     {
@@ -269,6 +280,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that invoke does not retry write commands on transient RPC failure.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task InvokeAsync_DoesNotRetryWriteCommand()
     {
@@ -284,6 +296,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that invoke helpers pass cancellation token to the transport.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task InvokeHelpers_PassCancellationTokenToTransport()
     {
@@ -330,6 +343,7 @@ public sealed class MxGatewayClientSessionTests
     }
 
     /// <summary>Verifies that WriteArrayElementsAsync builds a write command whose value is a SparseArrayValue.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]
     public async Task WriteArrayElementsAsync_BuildsWriteCommandWithSparseArrayValue()
     {