Z Score k3x3

// ===================================
// Z-Score Indicator with Enhanced Visualization
//
// Description:
// This indicator calculates the Z-Score (standard score) of price movements,
// highlighting extreme overbought and oversold conditions with visual alerts.
//
// Features:
// - Dynamic color gradients based on Z-Score values
// - Visual alerts for extreme zones (|Z| > 2)
// - Background highlighting for overbought/oversold areas
// - Shape markers for extreme conditions
// - Customizable period length and standard deviation levels
//
// Interpretation:
// Z > +2: Extreme overbought (red alert)
// Z < -2: Extreme oversold (green alert)
// |Z| < 1: Normal range (neutral colors)
// ===================================