/**
 * Startup stage timestamps: where the time goes between process start and a
 * runner that is online with its models and Python ready.
 *
 * Stages (first mark wins, epoch ms):
 *   process_start     the Node process began (performance.timeOrigin)
 *   config            options parsed and the token is in hand
 *   socket_connected  the Socket.IO handshake succeeded
 *   online            hello sent, relay up: the server can route work here
 *   python_ready      a supported Python interpreter is resolved
 *   discovery_done    the local model scan finished and was published
 *
 * The socket no longer waits for Python or discovery, so the last two usually
 * land after `online`. Reported to the desktop app (log line + a "timings"
 * host message) and printed with --diagnostics.
 */
export declare const STARTUP_STAGES: readonly ["process_start", "config", "socket_connected", "online", "python_ready", "discovery_done"];
export type StartupStage = (typeof STARTUP_STAGES)[number];
/** Record a stage once. Later marks of the same stage are ignored. */
export declare function markStage(stage: StartupStage, at?: number): void;
/** Called after every new stage mark. Returns an unsubscribe function. */
export declare function onStage(cb: (stage: StartupStage, at: number) => void): () => void;
export declare function stageMarked(stage: StartupStage): boolean;
/** True once every stage has been recorded. */
export declare function startupComplete(): boolean;
/** Epoch timestamps and offsets from process start, in stage order. */
export declare function startupTimings(): {
    at: Partial<Record<StartupStage, number>>;
    sinceStartMs: Partial<Record<StartupStage, number>>;
};
/** Human-readable timeline, one stage per line. */
export declare function formatStartupTimings(): string;
/** Test seam. */
export declare function _resetStartupTimings(): void;