Add external compose support in the docker role

- Use ansible.posix.synchronize for compose.yml
- Set fact for compose service restarts
- Introduce plain Docker dev host
- Optionally verify repos via GPG before sync
- Hide docker_repos_path in .folder
- Tweak .env for conciseness
- Add --diff to Ansible in Vagrantfile
- Clean output with loop_control
- Embed GPG in base role

roles/base/tasks/system.yml

@@ -4,6 +4,11 @@
     state: present
     update_cache: true
 
+- name: Install GPG
+  ansible.builtin.apt:
+    name: gpg
+    state: present
+
 - name: Manage root authorized_keys
   ansible.builtin.template:
     src: authorized_keys.j2