/**
 * Recursively sanitizes an object by removing keys that could cause prototype pollution.
 *
 * This function removes dangerous keys like `__proto__`, `constructor`, and `prototype`
 * from objects to prevent prototype pollution attacks when merging untrusted JSON data.
 *
 * @param obj - The object to sanitize
 * @returns A new object with dangerous keys removed
 *
 * @example
 * const malicious = { "__proto__": { "polluted": true }, "safe": "value" };
 * sanitizeObject(malicious); // { "safe": "value" }
 *
 * @example
 * const nested = { "config": { "__proto__": { "bad": true }, "port": 3000 } };
 * sanitizeObject(nested); // { "config": { "port": 3000 } }
 */
export declare const sanitizeObject: (obj: Record<string, unknown>) => Record<string, unknown>;