updated the mileage tracking system — City-Racing Steam update #494045

Key Improvements:1.Per-Lap Mileage Tracking: Now tracks currentLapMileage and stores each lap's mileage in lapMileages list2.Track-Based Session Management: New TrackMileageRecord class groups all sessions per track3.Session Numbering: Each race on a track gets a sequential session number (1st, 2nd, 3rd attempt, etc.)4.Enhanced CSV Export: Includes per-lap data with proper headers and metadata5.Data Versioning: Both MileageDatabase and RaceHistory now have version fields for future migration6.Clear Data Separation: Track name stored in every session, preventing confusion when restarting7.Improved Diagnostics: Shows current lap mileage in real-timeThe CSV export now looks like:# Race Data Export# Racer: MuscleCarClassic# Track: CityRacing1# Session Number: 1# Date: 2025-01-23 14:30:00# Total Race Time: 180.500 seconds# Total Race Mileage: 5.234 miles#Lap,LapTime(sec),LapMileage(miles),Rac...