Real-time updates

With live data, a candle with the same timestamp updates the current bar:

// New bar
smc.update(105, 100, 102, 104, 1700000000, 500)

// Same timestamp = updates the current bar in place (efficient)
smc.update(107, 100, 102, 106, 1700000000, 800)

// New timestamp = new bar
smc.update(108, 103, 106, 107, 1700000060, 600)