v0.5.4 of driving_conditions

Turn weather data into driving safety guidance. Road surface classification, grip estimation, visibility degradation, and Monte Carlo safety scoring. Pure Dart, no Flutter dependency. Changelog excerpt: - deps: allow fleet_hazard: ^0.4.0→ ^0.5.0(the anonymized-HazardZonedignity fix). driving_conditionsconsumes only the FleetReportinput atom and the RoadConditionenum via FleetHazardConfidenceAdapter— neither changed in fleet_hazard 0.5.0 (only the retained HazardZone.reportstype was anonymized from Listto List, which this package never reads). Source-compatible; no lib/code change. Unblocks integrators that pull both packages from pub.dev.