Adds systemd service that automatically grows the root filesystem on boot:
- Detects partition layout and grows partition if needed (growpart)
- Supports both ext4 (resize2fs) and btrfs filesystems
- Works with VIRTIO-SCSI disk (/dev/sda)
- Enables seamless live disk resize from the hosting platform
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
