- Add confirm_installation() function with detailed warning dialog
- Show target disk information (size, model, device path)
- Warn users that all data will be completely erased
- Support graphical confirmation (zenity), text-based (dialog), and terminal fallback
- Require explicit 'yes' confirmation before proceeding
- Add as step 4 before any disk partitioning or formatting
- Update total steps from 8 to 9 and renumber subsequent steps
- Installation can be safely cancelled without any changes to target disk
- Improves safety by preventing accidental data loss