Changes
- Prevent duplicate auto-queued jobs (prune, s3_sync) when backups complete close together
- Fix missing 'name' key error in S3 restore copy mode
- Add heartbeat thread to keep agent online during long-running tasks
- Remove package manager borg when installing binary version to avoid conflicts
- Beautified agent installer with colors, spinners, and better status messages
- Improved borg version detection to prefer /usr/local/bin/borg