Remove unused AudioFrame10ms/20ms structs, disable_failed_vad_backend(), and ServerState dead accessors (replace_from_snapshot, channel_count, client_count). Update tests to use .channels().count()/.clients().count().
Remove unused AudioFrame10ms/20ms structs, disable_failed_vad_backend(), and ServerState dead accessors (replace_from_snapshot, channel_count, client_count). Update tests to use .channels().count()/.clients().count().