/**
 * Normalize a phone + country code pair into a single E.164-style string.
 *
 * Rules (shared by login-entry submission and the SSO flow's identifier /
 * signup-details handlers):
 * - Trim the phone value.
 * - Empty phone → `''`.
 * - Phone already starting with `+` → return as-is (caller-supplied E.164).
 * - Otherwise: strip non-digits from the country code; prefix `+{cc}{phone}`
 *   if a country code is present, else return the bare phone digits.
 */
export declare function buildPhoneRecipient(phone?: string, countryCode?: string): string;
