Add Export/Import Lap Data Feature

[Gupta-02]

Users should be able to export their lap times to CSV/JSON for analysis and import previously saved sessions. This would be valuable for athletes, productivity tracking, and data analysis.

Features to implement:

Export button that downloads lap data as CSV Export button that downloads lap data as JSON Import functionality to load previously exported sessions Display export/import options in a clean modal or dropdown Technical Details:

CSV format: Lap Number,Time,Difference JSON format: Array of lap objects with timestamp, duration, difference Include session metadata (date, total time, etc.) Validate imported data format Files to modify:

script.js - Add export/import functions index.html - Add export/import buttons style.css - Style the export/import UI