handleRouteChange called applyConfiguration() unconditionally, which called
setCategory/setPreferredInput/etc., which triggered another route-change
notification, which called applyConfiguration() again — an infinite loop that
burned CPU (phone slowdown) and repeatedly tore down/rebuilt the audio session
(audio cycling on/off, VoiceOver glitching).
Two fixes:
1. handleRouteChange now only re-applies config on external device changes
(.oldDeviceUnavailable / .newDeviceAvailable), not on .categoryChange /
.routeConfigurationChange which are triggered by our own setCategory calls.
2. IOSAudioRouter.applyConfiguration() gained a re-entrancy guard
(isApplyingConfiguration) for synchronous route-change notifications.
Also added os.Logger logging to both files (subsystem cat.voice.VoiceCatiOS)
so future issues can be debugged from Console.app on the Mac.
Talon
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