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/proxmox/tasks/main.yml

@@ -0,0 +1,12 @@
+---
+# ansible/roles/proxmox/tasks/main.yml
+#
+# Main entry point for the proxmox role.
+# Add existing tasks above the OIDC include as needed.
+
+- name: Configure Authentik OIDC authentication
+  ansible.builtin.include_tasks: oidc.yml
+  tags:
+    - proxmox-oidc
+    - oidc
+    - authentik