refactor(vars): add system/hypervisor dict inputs

- Normalize new system_cfg + hypervisor_cfg and keep legacy vm_* and hypervisor_* aliases

- Support multiple system.disks (creation + optional mount + fstab generation)

- Add system_check safety role (production + existing system detection)

- Update README and example inventories

roles/configuration/defaults/main.yml

@@ -0,0 +1,5 @@
+---
+configuration_motd_enabled: "{{ motd_enabled | bool }}"
+configuration_sudo_banner_enabled: "{{ sudo_banner_enabled | bool }}"
+configuration_firewall_enabled: "{{ firewall_enabled | bool }}"
+configuration_luks_enabled: "{{ luks_enabled | bool }}"