feat(pb,task): moves input validation into separated tasks files. Play fails immediately if a validation fails

tasks/human_admin_user_validation.yaml

@@ -0,0 +1,22 @@
+--- 
+
+- name: Set default human admin user
+  ansible.builtin.set_fact:
+    lxc_human_admin_user: true
+
+- name: Prompt for human admin user creation with immediate validation
+  ansible.builtin.pause:
+    prompt: "Create human admin user? (true/false) [true]"
+  register: human_admin_user_result
+  until: >
+    human_admin_user_result.user_input | length == 0 or
+    (
+      human_admin_user_result.user_input in ['true', 'false']
+    )
+  retries: 2
+  delay: 0
+
+- name: Use user input only if provided, otherwise keep the default
+  ansible.builtin.set_fact:
+    lxc_human_admin_user: "{{ human_admin_user_result.user_input }}"
+  when: human_admin_user_result.user_input | length > 0