export type PreviewLoadTraceLevel = 'debug' | 'info' | 'warn' | 'error';
export interface PreviewLoadTraceEntry {
    id: string;
    sessionId: string;
    createdAt: number;
    isoTime: string;
    perfTimeMs: number | null;
    level: PreviewLoadTraceLevel;
    event: string;
    data: Record<string, unknown> | null;
}
export interface PreviewLoadTraceSnapshot {
    storageKey: string;
    currentSessionId: string;
    updatedAt: number;
    entries: PreviewLoadTraceEntry[];
}
type PreviewLoadTraceListener = (snapshot: PreviewLoadTraceSnapshot) => void;
export declare class PreviewLoadTraceStore {
    private state;
    private readonly listeners;
    constructor();
    getStorageKey(): string;
    getSnapshot(): PreviewLoadTraceSnapshot;
    subscribe(listener: PreviewLoadTraceListener): () => void;
    append(input: {
        level: PreviewLoadTraceLevel;
        event: string;
        data?: Record<string, unknown> | null;
    }): PreviewLoadTraceEntry;
    clear(): void;
    exportJson(limit?: number): string;
    private persist;
    private emit;
}
export declare const previewLoadTraceStore: PreviewLoadTraceStore;
export {};
