/**
 * Collapse a list of zoned intervals into the minimum set of non-overlapping intervals.
 *
 * - List-form generalization of `intervalUnionZoned`, which is pairwise only.
 * - Comparison and merging use each interval's instant, so intervals may carry different time
 *   zones.
 * - Intervals are merged when they overlap or share an instant exactly (adjacent intervals
 *   ARE merged).
 * - Order of the input list does not matter; the result is sorted by start instant. Each merged
 *   record's `start`/`end` strings carry the time zone of whichever input interval contributed
 *   that boundary.
 * - Returns `[]` for an empty list.
 * - Returns `[]` when `intervals` is not an array, when any element is not a
 *   `{ start, end }` record of valid ISO ZonedDateTime strings, or when any element has
 *   `start > end` or a leap-second string.
 * - Accepts GMT calendar-annotated zoned strings (as produced by `convertZonedToCalendar`) as
 *   well as bare ISO ones — E7 (issue #152) — but **rejects a mismatched set**: every endpoint in
 *   the list must name the same calendar system (E7's D4-zoned). This function returns *values*
 *   the caller reads back as datetimes, and an array whose elements carried different calendar
 *   tags would be unreadable as a set. A mismatch returns `[]`.
 * - Output boundaries are re-derived in the resolved calendar via `formatZonedInCalendar`, never
 *   copied from an input string (E7's D7-zoned).
 *
 * @param intervals array of `{ start, end }` records
 * @returns the minimum set of non-overlapping `{ start, end }` records, sorted by start, or `[]` on invalid input
 *
 * @example mergeIntervalsZoned([{ start: "2024-01-01T00:00:00+00:00[UTC]", end: "2024-01-10T00:00:00+00:00[UTC]" }, { start: "2024-01-05T00:00:00+00:00[UTC]", end: "2024-01-15T00:00:00+00:00[UTC]" }]) // [{ start: "2024-01-01T00:00:00+00:00[UTC]", end: "2024-01-15T00:00:00+00:00[UTC]" }]
 * @example mergeIntervalsZoned([]) // []
 */
export declare function mergeIntervalsZoned(intervals: Array<{
    start: string;
    end: string;
}>): Array<{
    start: string;
    end: string;
}>;