refactor: consolidate all roles into ansible/roles/ and update ansible.cfg

- Move all roles from playbooks/roles/ to roles/
- Update roles_path in ansible.cfg
- Add cast user to common role
- Create standalone podman role
- Add semaphore role with Podman + Quadlet support

ansible/roles/common/templates/chrony.conf.j2

@@ -0,0 +1,5 @@
+# Managed by Ansible — do not edit manually
+server {{ common_ntp_server }} iburst
+driftfile /var/lib/chrony/chrony.drift
+makestep 1.0 3
+rtcsync