Initial Ansible automation for hobbs.farm infrastructure

Complete IaC covering:
- 14 roles: common, docker, traefik, vaultwarden, monitoring, media, matrix,
  home_assistant, frigate, adguard, gitea, semaphore, openclaw, security, backup
- Inventory for all hosts (Peggy, Bart, Yoda, NAS, Firewalla)
- Stack playbooks: core-infrastructure, monitoring, media, communication,
  automation, smarthome, security-hardening
- Maintenance playbooks: update-containers, backup, health-check
- Production Docker Compose templates with Traefik labels
- Security hardening (sysctl, auditd, UFW, fail2ban)
- Automated backups with retention policy

playbooks/maintenance/backup.yml

@@ -0,0 +1,42 @@
+---
+- name: Run backups
+  hosts: docker_hosts
+  become: true
+  tasks:
+    - name: Ensure backup destination exists
+      ansible.builtin.file:
+        path: "{{ backup_destination }}"
+        state: directory
+        mode: "0750"
+      tags: [backup]
+
+    - name: Run backup script
+      ansible.builtin.command:
+        cmd: /usr/local/bin/homelab-backup.sh
+      register: backup_result
+      changed_when: backup_result.rc == 0
+      tags: [backup]
+
+    - name: Display backup result
+      ansible.builtin.debug:
+        msg: "{{ backup_result.stdout_lines }}"
+      tags: [backup]
+
+    - name: Clean up backups older than 30 days
+      ansible.builtin.find:
+        paths: "{{ backup_destination }}"
+        age: 30d
+        recurse: false
+        file_type: file
+        patterns: "*.tar.gz"
+      register: old_backups
+      tags: [backup, cleanup]
+
+    - name: Remove old backups
+      ansible.builtin.file:
+        path: "{{ item.path }}"
+        state: absent
+      loop: "{{ old_backups.files }}"
+      loop_control:
+        label: "{{ item.path | basename }}"
+      tags: [backup, cleanup]