toggl_to_sp.py — Migrate Toggl Track CSV exports into Super Productivity backup JSON.

Usage: python3 toggl_to_sp.py --backup backup.json --csvs toggl1.csv toggl2.csv --output out.json

Design:

• Every unique (project, description, date) combo → one archive task (isDone=True)
• Multiple Toggl entries with same project+description+date are MERGED (time accumulates)
• All tasks go into archiveYoung (history, not live work view)
• data.timeTracking.project is NOT modified — it tracks live timer sessions, not history
• Existing SP data (tasks, projects, tags) is preserved
• IDs are 22-char alphanumeric strings matching SP's own pattern