Function: findFreeSlotsInWindows()

function findFreeSlotsInWindows(args: {
  busy: TimeRange[];
  duration: Duration;
  step?: Duration;
  windows: TimeRange[];
}): TimeRange[];

Return every slot of duration that fits inside windows without overlapping busy.

windows are caller-precomputed open ranges (e.g. working-hour segments already intersected with the search horizon).
busy is compared by absolute instant — time-zone IDs may differ between windows and busy entries; Temporal.ZonedDateTime.compare normalises to UTC before comparing.
step defaults to duration (non-overlapping, adjacent slots). step < duration produces overlapping start times. step > duration leaves gaps between slots.

Parameters

Parameter	Type
`args`	{ `busy`: `TimeRange`[]; `duration`: `Duration`; `step?`: `Duration`; `windows`: `TimeRange`[]; }
`args.busy`	`TimeRange`[]
`args.duration`	`Duration`
`args.step?`	`Duration`
`args.windows`	`TimeRange`[]