Resolve Worker.Tests-008..015 code-review findings

Worker.Tests-008: moved the misplaced WorkerLogRedactor test out of
VariantConverterTests into Bootstrap/WorkerLogRedactorTests.

Worker.Tests-009: renamed 46 snake_case alarm-test methods to PascalCase
Method_Scenario_Expectation.

Worker.Tests-010: replaced a weak Assert.Contains with an exact assertion
against the real diagnostic message and corrected the XML doc.

Worker.Tests-011: renamed and re-documented a cancellation test that
overstated what it proved.

Worker.Tests-012: added an oversized-frame (MessageTooLarge) test; renamed
the mislabeled zero-length-payload test.

Worker.Tests-013: removed the fixed-100ms ThrowIfCompletedAsync helper; the
caller now races runTask deterministically.

Worker.Tests-014: consolidated duplicated test fakes/helpers
(FakeRuntimeSession, NoopComApartmentInitializer, NoopEventSink, frame
helpers) into a shared TestSupport namespace.

Worker.Tests-015: added MxAccessEventQueue coverage for drain-all (maxEvents
0), empty-queue drain, and enqueue-after-fault.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/MxGateway.Worker.Tests/Ipc/WorkerPipeClientTests.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.IO;
 using System.IO.Pipes;
 using System.Threading;
@@ -9,8 +8,7 @@ using MxGateway.Contracts;
 using MxGateway.Contracts.Proto;
 using MxGateway.Worker.Bootstrap;
 using MxGateway.Worker.Ipc;
-using MxGateway.Worker.MxAccess;
-using MxGateway.Worker.Sta;
+using MxGateway.Worker.Tests.TestSupport;
 
 namespace MxGateway.Worker.Tests.Ipc;
 
@@ -213,100 +211,4 @@ public sealed class WorkerPipeClientTests
             },
         };
     }
-
-    private sealed class FakeRuntimeSession : IWorkerRuntimeSession
-    {
-        /// <summary>Starts the worker session.</summary>
-        /// <param name="sessionId">Session ID.</param>
-        /// <param name="workerProcessId">Worker process ID.</param>
-        /// <param name="cancellationToken">Cancellation token.</param>
-        /// <returns>Worker ready response.</returns>
-        public Task<WorkerReady> StartAsync(
-            string sessionId,
-            int workerProcessId,
-            CancellationToken cancellationToken = default)
-        {
-            return Task.FromResult(new WorkerReady
-            {
-                WorkerProcessId = workerProcessId,
-                MxaccessProgid = MxGateway.Worker.MxAccess.MxAccessInteropInfo.ProgId,
-                MxaccessClsid = MxGateway.Worker.MxAccess.MxAccessInteropInfo.Clsid,
-                ReadyTimestamp = Timestamp.FromDateTimeOffset(DateTimeOffset.UtcNow),
-            });
-        }
-
-        /// <summary>Dispatches a command to STA thread.</summary>
-        /// <param name="command">The command.</param>
-        /// <returns>Command reply.</returns>
-        public Task<MxCommandReply> DispatchAsync(StaCommand command)
-        {
-            return Task.FromResult(new MxCommandReply
-            {
-                SessionId = command.SessionId,
-                CorrelationId = command.CorrelationId,
-                Kind = command.Kind,
-                ProtocolStatus = new ProtocolStatus
-                {
-                    Code = ProtocolStatusCode.Ok,
-                    Message = "OK",
-                },
-            });
-        }
-
-        /// <summary>Captures current runtime heartbeat snapshot.</summary>
-        /// <returns>Heartbeat snapshot.</returns>
-        public WorkerRuntimeHeartbeatSnapshot CaptureHeartbeat()
-        {
-            return new WorkerRuntimeHeartbeatSnapshot(
-                DateTimeOffset.UtcNow,
-                pendingCommandCount: 0,
-                outboundEventQueueDepth: 0,
-                lastEventSequence: 0,
-                currentCommandCorrelationId: string.Empty);
-        }
-
-        /// <summary>Drains queued events.</summary>
-        /// <param name="maxEvents">Maximum events to drain.</param>
-        /// <returns>Drained events.</returns>
-        public IReadOnlyList<WorkerEvent> DrainEvents(uint maxEvents)
-        {
-            return Array.Empty<WorkerEvent>();
-        }
-
-        /// <summary>Drains pending fault if any.</summary>
-        /// <returns>Fault or null.</returns>
-        public WorkerFault? DrainFault()
-        {
-            return null;
-        }
-
-        /// <summary>Cancels a command by correlation ID.</summary>
-        /// <param name="correlationId">Command correlation ID.</param>
-        /// <returns>True if cancelled.</returns>
-        public bool CancelCommand(string correlationId)
-        {
-            return false;
-        }
-
-        /// <summary>Requests graceful shutdown.</summary>
-        public void RequestShutdown()
-        {
-        }
-
-        /// <summary>Shuts down gracefully within timeout.</summary>
-        /// <param name="timeout">Shutdown timeout.</param>
-        /// <param name="cancellationToken">Cancellation token.</param>
-        /// <returns>Shutdown result.</returns>
-        public Task<MxAccessShutdownResult> ShutdownGracefullyAsync(
-            TimeSpan timeout,
-            CancellationToken cancellationToken = default)
-        {
-            return Task.FromResult(new MxAccessShutdownResult(Array.Empty<MxAccessShutdownFailure>()));
-        }
-
-        /// <summary>Disposes resources.</summary>
-        public void Dispose()
-        {
-        }
-    }
 }