/**
 * What the login screen says about a refused sign-in.
 *
 * The server's message is written for whoever reads the API response, and some
 * of them are instructions for a developer. A Google sign-in onto an address
 * that already has an unverified password account used to put this in front of
 * the visitor:
 *
 *     … Sign in with your existing method, then POST to /auth/link/google to
 *     link google to your account.
 *
 * So the codes a person can act on get the screen's own, translated words, and
 * every other error keeps the server's message, which is still the most
 * specific thing there is to show.
 */
export declare function authErrorMessage(error: unknown, t: (key: string) => string): string;