backoff

type Config struct {
	// InitialInterval is the base sleep duration before the first retry.
	InitialInterval time.Duration

	// MaxInterval is the upper bound on the computed sleep duration.
	MaxInterval time.Duration

	// Multiplier is applied to the interval on each successive attempt.
	// A value of 2.0 doubles the interval each time.
	Multiplier float64

	// RandomFactor is the fraction of the interval added as jitter.
	// 0.0 = no jitter, 1.0 = up to ±100% jitter (full jitter).
	RandomFactor float64
}