feat: Add Docker Registry deployment role

[pparage]

Problem

No Ansible role exists for deploying a Docker Registry. The demo_lab creates a VM (admin-builder-docker-registry, VMID 1001) but the VM doesn't even have Docker installed.

Needed

A catalog role (e.g., software.install.docker_registry) that:

1. Installs Docker (if not already present)
2. Runs a Docker Registry container
3. Configures TLS or insecure registry settings
4. Sets up storage backend

Related

• Tracked in range42/project_management#66