Class CandleMerger

Cancel any pending RAF and mark the merger as destroyed so late frames produced by a prior _scheduleUpdate call don't fire against torn-down state.

Load historical candles

Merge realtime candle updates

Set the render callback (called at most once per frame). info.realtime is true when the coalesced frame included at least one realtime merge (mergeRealtime) — history loads (loadHistory) report false so callers can scope behavior like max-candle eviction to live appends and not undo a freshly-prepended history page.