Type Alias EngineChannel

Channels the engine store emits on. Pick the channel matching the slice cadence so consumers do not wake up on unrelated mutations.

• time: emits per paint (raw ms; bucketing lives in hook selectors).
• frame: emits per settled cursor frame (frame-index changes).
• state: coarse status transitions (load, play, pause, end, error).
• duration: once per loaded source.
• seeking: cursor scrub-in-flight transitions (opt-in indicator).
• rate: playback-rate changes. Rare, and on its own channel so a rate readout does not wake on status and vice versa.