find_heart_route_in_city
Find an existing heart-shaped running route in a given city. Returns up to 5 AI-validated routes matching the city (and optionally a target distance). Use this when a user mentions a city and wants a heart route — e.g. "find me a heart-shaped route in Paris" or "I want to run a heart in Tokyo for my mum's birthday".
city必填prefer_goldmax_distance_km