export declare class AvoEncryption {
    /**
     * Determines whether encryption should be applied.
     *
     * Truth table:
     *   dev + key    => true
     *   staging + key => true
     *   prod + key   => false
     *   dev + null   => false
     *   dev + ""     => false
     */
    static shouldEncrypt(env: string, publicEncryptionKey: string | undefined | null): boolean;
    /**
     * Returns true if the propertyType represents a list type (e.g. "list(string)").
     */
    static isListType(propertyType: string): boolean;
    /**
     * Encrypts a string value using ECIES with prime256v1.
     *
     * Wire format: [0x00][65-byte ephemeral pubkey][16-byte IV][16-byte auth tag][ciphertext]
     * Output is base64-encoded.
     *
     * Returns null on failure, logging a warning.
     */
    static encryptValue(value: string, recipientPubKeyHex: string): string | null;
}