Backend VenueListItem missing address fields that frontend expects

## Bug Frontend VenueListItem type expects address_line1, address_line2, postal_code but backend VenueListItem only returns name, city, region, country_code, latitude, longitude, place_id. ## Impact Venue search/picker dropdowns show venue names but no addresses. Users cannot distinguish venues with the same name in different locations. ## Fix Add address_line1, address_line2, postal_code to backend VenueListItem schema. ## Found by API contract audit (2026-03-19)