AudioEventCursor
class AudioEventCursor
One view's ordered event reader across every source. Call from one consumer thread, with the authoritative media time. Initial attachment and gaps over 250 ms discard past bursts. A late transient may arrive up to 30 ms late and a late structural confirmation up to 3 s late; song map events are delivered on time only. sample reports every kind of discard. Pausing never emits an event.