Smart Automatic Activity Merging for Dual Recording

[hdkiller]

💡 Summary

Implement an intelligent system to detect and merge duplicate activities resulting from "Dual Recording" (e.g., recording on Zwift and a Garmin head unit simultaneously).

🤷 Motivation / Use Case

Athletes often record sessions on multiple devices to capture different metrics (e.g., Zwift for virtual distance/map, Garmin for Cycling Dynamics). Manually managing these duplicates is tedious.

📋 Detailed Requirements

• Detection Logic: Identify overlapping activities based on timestamp, duration, and heart rate/power patterns.
• Data Fusion: Automatically merge streams (e.g., keep Zwift's GPS track and elevation while injecting Garmin's L/R balance and advanced dynamics).
• Preference Settings: Allow users to define a "primary" source for specific data types.

✅ Acceptance Criteria

• System automatically flags dual recordings.
• Users can approve or automate the merging of these activities.
• The resulting merged activity contains the best data from both sources without duplication of volume.