Number of valid candles in this view.
Index of the first candle in the parent buffer.
OptionalrepPresent only on a conflated (downsampled) view: for each aggregated
bucket, the buffer index of its first candle. Renderers position a
bucket via viewport.indexToX(repIndex[i]) instead of offset + i.
Absent on normal views, so the standard render path is unaffected.
Zero-copy typed-array view into a contiguous range of candles in the underlying
CandleBuffer. Renderers consume this shape directly to avoid per-candle object allocation on the hot rendering path.