fix: resolve Client.Java + Worker.Tests findings (pending windev verification)

Client.Java-040..048, Worker.Tests-034/035/036. Edits applied on the Mac,
which has no JRE and cannot build the x86+MXAccess worker tests; findings are
marked In Progress pending gradle + x86 build verification on windev. Do not
mark Resolved until verified there.

src/ZB.MOM.WW.MxGateway.Worker.Tests/Ipc/WorkerPipeSessionTests.cs

@@ -980,7 +980,11 @@ public sealed class WorkerPipeSessionTests
         Task runTask = session.RunAsync(cancellation.Token);
         await CompleteGatewayHandshakeAsync(pipePair, cancellation.Token);
 
-        DateTimeOffset start = DateTimeOffset.UtcNow;
+        // The heartbeatWait CTS (5s cancel-after) already enforces the timing bound:
+        // if the first heartbeat is not received within 5s, ReadUntilAsync throws
+        // OperationCanceledException and the test fails.  A redundant wall-clock
+        // elapsed < 5s assertion would add the same class of flakiness
+        // Workers.Tests-003/004/013/020 corrected elsewhere, so it is omitted here.
         using CancellationTokenSource heartbeatWait = CancellationTokenSource
             .CreateLinkedTokenSource(cancellation.Token);
         heartbeatWait.CancelAfter(TimeSpan.FromSeconds(5));
@@ -988,12 +992,8 @@ public sealed class WorkerPipeSessionTests
             pipePair.GatewayReader,
             WorkerEnvelope.BodyOneofCase.WorkerHeartbeat,
             heartbeatWait.Token);
-        TimeSpan elapsed = DateTimeOffset.UtcNow - start;
 
         Assert.Equal(WorkerEnvelope.BodyOneofCase.WorkerHeartbeat, heartbeat.BodyCase);
-        Assert.True(
-            elapsed < TimeSpan.FromSeconds(5),
-            $"First heartbeat took {elapsed}, expected well under the 30s interval.");
 
         await SendShutdownAndWaitAsync(pipePair, runTask, cancellation.Token);
     }