ios: play within one engine round trip of a pause can have its intent cleared by the pause report #708

In IosPlayerController (shared/src/commonMain/.../playback/IosPlayerController.kt, pauseNow / onStateChanged), a play that arrives after a pause but before the engine's paused report lands has its play intent cleared by that report while the engine's audio has already started. Expected: the paused report for the earlier pause is recognised as stale once a newer play has been issued.

Pre-existing race (window is one engine round trip, milliseconds). After the #696 landing the UI shows Paused as soon as the pause is sent, so a quick toggle can now reach it. Seen in review only, not reproduced on a device (unverified).

Related: #694, #707.