Agent improvements:
- Add get_logged_in_users() function to SystemCollector using 'who' command
- Collect unique, sorted list of currently logged-in users
- Include logged_in_users field in system metrics JSON output
- Change C-state formatting to show 2 states per row instead of 4
Dashboard improvements:
- Update Backups widget to show "Archives: XX, ..." format
- System widget ready to display logged-in users with proper formatting
The System widget will now show:
- C-states formatted as 2 per row for better readability
- Logged-in users displayed as "Logged in: user" or "Logged in: X users (user1, user2)"