fix(macos): avoid stale dashboard command assertions (#144710)

fix(macos): avoid stale dashboard command assertions (#144710)

* test(macos): probe delayed dashboard command polling

Establish a controlled delayed-consumer negative result in disposable native CI. Require a fresh WebKit read proving all three commands arrived after the unchanged deadline before the original loop asserts its stale sample. This instrumentation is temporary and must be removed before landing.

* test(macos): recheck commands after delayed polling

Apply the reviewed polling fix under the same controlled delayed-consumer schedule. Keep the five-second deadline and exact three-command assertion; require independent proof of actual delivery before the loop takes its own fresh sample. Remove the temporary scheduling instrumentation before landing.

* test(macos): remove controlled dashboard polling probe

Keep the proven fresh-sample polling order and safe failure diagnostics while removing the temporary response gate, delayed consumer, independent probe read, and marker. Preserve the original five-second deadline, ten-millisecond polling interval, and exact ordered three-command assertion.