import type { ArkmeTimelineItem } from '../types.js';
import type { ArkmeUnifiedTimelineWindow } from '../unified-chat-timeline.js';
/** Displayed message coverage excludes composer receipts and unavailable bodies. */
export declare function unifiedTimelineMessageSequence(window: ArkmeUnifiedTimelineWindow): number;
/** A refresh replaces history, but cannot settle an in-flight composer send. */
export declare function pendingUnifiedTimelineSends(items: readonly ArkmeTimelineItem[]): ArkmeTimelineItem[];
/** Sending tasks are receipts, not another source of chat history. */
export declare function unifiedTimelineSendOverlay(window: ArkmeUnifiedTimelineWindow, items: readonly ArkmeTimelineItem[], historicalFileIds?: ReadonlySet<string>): ArkmeTimelineItem[];
/** Stable linear merge: keep authoritative order and row identities intact. */
export declare function mergeTimelineSendRows<T extends {
    occurredAtMillis: number;
}, U extends {
    occurredAtMillis: number;
}>(canonical: readonly T[], sending: readonly U[]): Array<T | U>;
//# sourceMappingURL=unified-timeline-send-overlay.d.ts.map