/** True when CRTR_TIMING is set — guard expensive marker payloads with this. */
export declare function timingEnabled(): boolean;
/** Label this process in the timing log (e.g. 'viewer', 'broker'). */
export declare function timingProc(name: string): void;
/**
 * Record one phase marker. Columns:
 *   `+`  ms since the shared cross-process origin (the whole front-door clock)
 *   `Δ`  ms since the previous marker in THIS process
 *   `up` ms since this process started (same sense as broker `duration_ms`)
 */
export declare function mark(phase: string, fields?: Record<string, unknown>): void;