/**
 * Localization probe for DISPATCHED_BLIND queries.
 *
 * In remote dispatch the coordinator's _DONE counters are structurally blind
 * (it fans work out to subqueries and scans nothing itself). But a SMALL ENOUGH
 * time window forces the coordinator to scan LOCALLY — and then its scanned /
 * matched / skippedSearch / skippedTemplate counters are precise. So to debug a
 * blind zero-result query, the MCP re-submits a narrowed window of the SAME
 * query and reads the local counts, which pinpoint the failing stage
 * (resolve vs bloom vs filter).
 *
 * `narrowWindow` derives that small window at the END of the original range, in
 * the same `now(...)` / epoch syntax the engine accepts, so the probe samples
 * the same index + the same predicate as the original query.
 */
/** Parse a `now()` / `now("-Nx")` bound to seconds-before-now. Returns null for
 *  anything not in that relative form (e.g. an absolute epoch). */
export declare function nowOffsetSec(v: string): number | null;
export interface TimeWindow {
    from: string;
    to: string;
}
/**
 * Derive a `windowSec`-wide window anchored at the END of [from, to], expressed
 * in the engine's accepted syntax. Returns null when neither bound is a
 * recognizable `now(...)` offset or epoch — callers should fall back to a fixed
 * recent window.
 *
 *   narrowWindow('now("-2h")', 'now()', 60)        -> { from: 'now("-60s")',  to: 'now()' }
 *   narrowWindow('now("-15m")', 'now("-10m")', 60) -> { from: 'now("-660s")', to: 'now("-600s")' }
 *   narrowWindow('1781700000000','1781700300000',60)-> { from:'1781700240000', to:'1781700300000' }
 */
export declare function narrowWindow(from: string, to: string, windowSec?: number, skewSec?: number): TimeWindow | null;
/** A safe recent window when the original bounds can't be parsed: a `windowSec`
 *  slice ending `skewSec` ago (skew avoids the freshest, not-yet-indexed edge). */
export declare function recentFallbackWindow(windowSec?: number, skewSec?: number): TimeWindow;