/**
 * Detection of transient API errors on the TUI screen, used by the server
 * to auto-retry a turn that died on one (529 Overloaded, 5xx, timeout…).
 * Pure functions, kept separate from server.ts so they can be tested.
 */
/** Auto-retry backoff: first, second and third attempt. */
export declare const RETRY_DELAYS_MS: readonly number[];
/** The screen lines (trimmed) showing a transient API error. */
export declare function findTransientErrors(screen: string): string[];
/**
 * Multiset difference: the lines of `after` in excess of `before`. Used to
 * ignore an old error still visible on screen from a previous turn — only
 * a NEW occurrence triggers a retry.
 */
export declare function newTransientErrors(before: string[], after: string[]): string[];