The enhanced API path on FuelLogsRepository returned raw pg rows
straight to the service layer, so DECIMAL columns (fuel_units,
cost_per_unit, total_cost, gallons, price_per_gallon) arrived as
strings instead of numbers. The service layer compensated with
scattered Number() coercion in toEnhancedResponse and getVehicleStats,
and EfficiencyCalculationService silently leaned on JS string-to-
number coercion in division. Type signatures across the stack
declared number and the runtime delivered string.
Add a private mapEnhancedRow that coerces all DECIMAL columns with
parseFloat while preserving snake_case keys (the convention the
service layer already uses to access these rows). Apply it in every
enhanced read/write path: createEnhanced, findByVehicleIdEnhanced,
findByUserIdEnhanced, findByIdEnhanced, getPreviousLogByOdometer,
getLatestLogForVehicle, updateEnhanced. Drop the now-redundant
Number() wrappers in toEnhancedResponse and getVehicleStats.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
