Prepare a one-tap booking handoff for the user's chosen campground/dates.
Returns a pre-filled deep link to the operator's reservation page plus the
booking-window context (release date/time, ToS-compliant guidance, alert
suggestion) the agent needs to advise the user. Does NOT book on behalf —
third-party booking is prohibited by Recreation.gov, ReserveCalifornia,
ReserveAmerica, and every other supported public-land operator.
Pair with ``check_availability`` first to confirm the dates are reservable
and to surface site-specific ``booking_url`` values when available.
Args:
campground_id: Outdoorithm CUID (e.g. ``RecreationDotGov:232447``).
start_date: Check-in date (YYYY-MM-DD).
end_date: Check-out date (YYYY-MM-DD).
party_size: Optional group size. Surfaced in the user-facing summary;
most operators don't accept this in URL params, so it isn't
embedded in the deep link.
Connector