Function scheduled_gain 

pub fn scheduled_gain(
    op_point: f64,
    op_min: f64,
    op_max: f64,
    low_gain: f64,
    high_gain: f64,
) -> f64

Gain scheduling: linearly interpolate the gain between low_gain (at op_min) and high_gain (at op_max) for the current op_point — adaptive tuning across the operating envelope. Clamps outside [op_min, op_max].