Add migrate-to-rootless playbook

Provides a migration path for existing rootful deployments to the new
rootless Podman Quadlet setup. Handles stopping root-level services,
transferring data directory ownership, and starting the new user-scope
services.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: pablomh

src/playbooks/migrate-to-rootless/metadata.obsah.yaml

@@ -0,0 +1,15 @@
+---
+help: |
+  Migrate existing rootful Foreman deployment to rootless
+
+  WARNING: This is a destructive operation that will:
+  - Stop all running services
+  - Transfer ownership of data volumes
+  - Remove system-scoped systemd units
+  - Recreate everything in user scope
+
+  PREREQUISITES:
+  - Backup all data before running this migration
+  - Ensure no active users or operations are running
+  - Test this in a non-production environment first
+...