import type { Settings } from "../config/settings";
import { type LazyService } from "./lazy-service";
/** Runtime network prewarm and first-request latency diagnostics. */
export interface NetworkPrewarmRuntime {
    enabled: boolean;
    preconnect(baseUrl: string | undefined): void;
    recordFirstRequestLatency(latencyMs: number): void;
    getFirstRequestLatencyDeltaMs(): number | undefined;
}
/**
 * Keep network preconnect behind a lifecycle-owned LazyService. The service is
 * cheap to initialize even when disabled, so the disabled path can still
 * record the first-request latency delta without touching fetch.preconnect.
 */
export declare function createNetworkPrewarmService(settings: Settings): LazyService<NetworkPrewarmRuntime>;