- Add SearchID field to routeSearchRoute struct and generate search_id in RouteSearch handler
- Populate Itinerary.ID field with unique IDs using generateItineraryID function
- Fix information disclosure in error handling - log errors internally instead of leaking to clients
- Fix circuit breaker trip metric recording - only record when state transitions to open
- Fix context not passed in route expansion - use context.WithTimeout instead of context.TODO
- Fix admin auth fails open on missing API key - return 401 Unauthorized without revealing configuration
- Add Cost field to Edge and RouteLeg structs
- Propagate Cost in FindRoute itinerary creation
- Write TestRouteParetoRanking test verifying non-dominated route selection
