test: cover root configuration with Molecule

Verify SSH key rotation, file permissions, optional file removal and password management on Arch Linux, Debian and Fedora. Keep container dependencies scoped to the test scenario.

Co-authored-by: Copilot <copilot@github.com>

molecule/default/destroy.yml

@@ -0,0 +1,28 @@
+---
+- name: Destroy
+  hosts: localhost
+  gather_facts: false
+  tasks:
+  - name: Remove the container of every platform
+    community.docker.docker_container:
+      name: "{{ item.name }}"
+      state: absent
+    loop: "{{ molecule_yml.platforms }}"
+    loop_control:
+      label: "{{ item.name }}"
+
+  - name: Remove temporary SSH key pairs
+    ansible.builtin.file:
+      path: "{{ molecule_ephemeral_directory }}/{{ item }}"
+      state: absent
+    loop:
+    - original.ed25519
+    - original.ed25519.pub
+    - replacement.ed25519
+    - replacement.ed25519.pub
+
+  - name: Empty the instance config
+    ansible.builtin.copy:
+      content: "[]"
+      dest: "{{ molecule_instance_config }}"
+      mode: "0600"