fix(worker): session-owned stream disposal unblocks and observes the net48 pipe read at teardown

src/ZB.MOM.WW.MxGateway.Worker/Ipc/WorkerPipeClient.cs

@@ -151,6 +151,13 @@ public sealed class WorkerPipeClient : IWorkerPipeClient
 
         WorkerFrameProtocolOptions frameOptions = new(options);
 
+        // The session disposes this pipe itself as its last teardown step — that disposal is what
+        // unblocks a net48 pipe read the message loop abandoned, and it has to happen while the
+        // session still holds the read task so the resulting fault is observed rather than orphaned
+        // (see WorkerPipeSession.RunAsync). The `using` stays as the backstop for the paths the
+        // session never reaches: a session factory that throws, or a RunAsync that never gets past
+        // its own construction. Disposal is idempotent, so the second Dispose is a no-op — do not
+        // "clean up" this `using` on the assumption that it is now redundant.
         using NamedPipeClientStream pipe = await ConnectWithRetryAsync(options.PipeName, cancellationToken)
             .ConfigureAwait(false);