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/observer/files/grafana/provisioning/datasources/all.yml

@@ -0,0 +1,7 @@
+apiVersion: 1
+
+datasources:
+    - name: Prometheus
+      type: prometheus
+      access: proxy
+      url: http://192.168.0.1:9090