/**
 * Result of generating a new timestamp.
 */
export interface TimestampResult {
    /** The timestamp to use for the migration */
    timestamp: string;
    /** The new lastTimestamp value to store (may be same as timestamp) */
    newLastTimestamp: string;
}
/**
 * Generate the next unique migration timestamp.
 *
 * This is a PURE function - it does not mutate any state.
 * The caller is responsible for updating lastTimestamp in the build log.
 *
 * @param lastTimestamp - The last timestamp used (from build log)
 * @returns Object containing the new timestamp and the value to store as lastTimestamp
 */
export declare function getNextTimestamp(lastTimestamp: string): TimestampResult;