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/podman/defaults/main.yml

@@ -0,0 +1,18 @@
+---
+podman_packages:
+  - podman
+  - fuse-overlayfs
+  - slirp4netns
+  - containernetworking-plugins
+
+# Rootless user
+podman_rootless_user: cast
+
+# Registries
+podman_registries:
+  - prefix: "docker.io"
+    location: "docker.io"
+  - prefix: "quay.io"
+    location: "quay.io"
+  - prefix: "ghcr.io"
+    location: "ghcr.io"