refactor(vars): remove legacy variable inputs

- Require hypervisor as dict input and use hypervisor_cfg/hypervisor_type internally

- Remove vm_* and hypervisor_* compatibility aliases

- Update roles and docs to use system/hypervisor dictionaries only

roles/virtualization/tasks/main.yml

@@ -1,3 +1,3 @@
 ---
 - name: Create Virtual Machine
-  ansible.builtin.include_tasks: "{{ hypervisor }}.yml"
+  ansible.builtin.include_tasks: "{{ hypervisor_type }}.yml"