Resolve VSN-2407 "Feature/implement driver assignment, optimal search, and map routing logic"
- Implement core driver assignment logic (`PreparedTripDriverAssignmentService`) including manual assignment, unassignment, and time-conflict validation for prepared circuits.
- Integrate external services (`HrService`, `AbsenceService`, `UserService`) to fetch driver working hours, absences, and vehicle details for accurate availability filtering.
- Introduce optimal driver search and ranking algorithm integration (`DriverSearchService`, `RankCircuitRequest`, `CircuitRankingResponse`) to find the best drivers for prepared trips.
- Add `OpenRouteService` integration to calculate distances, durations, and approach route geometries (Empty KM).
- Create map visualization DTOs (`DriverMapResponseDTO`, `TripMapListDTO`) to expose driver home locations and approach polylines to the frontend.
- Update controllers, mappers, and API paths to expose the new assignment, unassignment, and map search endpoints.
Closes VSN-2407