/**
 * Helper function to check if a value has changed compared to the old value.
 * Uses deep equality comparison for arrays and objects.
 *
 * Key behaviors:
 * - `undefined` = field not provided (returns false)
 * - `null` = explicit value (returns true if different from oldVal)
 * - Empty values (`[]`, `{}`, `''`) are valid changes if oldVal differs
 *
 * @param newVal - The new value to check
 * @param oldVal - The old value to compare against
 * @returns true if the value has changed, false otherwise
 */
export default function hasChanged(newVal: any, oldVal: any): boolean;