Refactor Code

Improve existing Ansible YAML without changing the intended behaviour. Always preserve idempotency and follow ../../copilot-instructions.md.

What To Do

1. Upgrade module references — Replace bare module names with FQCN equivalents (e.g., apt → ansible.builtin.apt).
2. Fix task style — Convert any inline key=value task arguments to YAML dict syntax.
3. Improve names — Rewrite vague task name fields into clear, outcome-oriented Title Case sentences.
4. Flatten large task files — Break a tasks/main.yml with more than ~30 tasks into focused sub-task files imported via include_tasks.
5. Centralise variables — Move hardcoded values into defaults/main.yml with appropriate comments.
6. Fix idempotency gaps — Add changed_when: false or appropriate guards to command/shell tasks.
7. Add handlers — Replace inline service restarts with + handler pattern.