- Add refresh_tle_data() function for reusable TLE updates
- Automatically fetch fresh TLE from CelesTrak when app starts
- Runs in background thread to avoid slowing down startup
- Includes NOAA-20 and NOAA-21 in name mappings
- Gracefully handles failures (uses cached data if offline)
- Existing /update-tle endpoint now uses shared function
This ensures satellite tracking data is always fresh, fixing
inaccurate positions caused by stale TLE data.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>