List Sparkling Tracks tour packages with optional filters. Returns a compact summary (id, title, route, starting per-person price in EUR for the land-only option, the with-flights total when available (price_eur_with_flights), whether flights are optional (flights_optional), an approximate price in the requested currency, duration, badges, URL). The default starting price is land-only (without flights); customers can add round-trip flights. Optional date_from/date_to (ISO YYYY-MM-DD) filter by the real departure calendar: combined with a destination city they keep only packages whose stay in that city overlaps the range (annotated with city_date_windows); dates alone keep only packages that fit entirely inside the range. Accepts optional language and currency params; city names, country names, and trip titles are translated when a supported locale is requested. Tour packages are quote-based: prices are starting per-person prices, final pricing depends on party size, dates, and customisations. Every response carries price_basis, which states the exactness of every price field it returns (these are "from" prices, never per-date quotes) and the booking path. A package on a coach route that is also sold in other editions carries an editions count; get_package_details returns those editions in its family block. Use get_package_details for the full itinerary.