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

roles/backup/tasks/main.yml

@@ -0,0 +1,43 @@
+---
+- name: Ensure backup destination directory exists
+  ansible.builtin.file:
+    path: "{{ backup_destination }}"
+    state: directory
+    owner: glyptic
+    group: glyptic
+    mode: "0750"
+  tags: [backup]
+
+- name: Deploy backup script
+  ansible.builtin.template:
+    src: backup.sh.j2
+    dest: "{{ backup_script_path }}"
+    owner: root
+    group: root
+    mode: "0750"
+  tags: [backup]
+
+- name: Configure backup cron job
+  ansible.builtin.cron:
+    name: "homelab-backup"
+    minute: "0"
+    hour: "2"
+    job: "{{ backup_script_path }} >> /var/log/homelab-backup.log 2>&1"
+    user: root
+  tags: [backup]
+
+- name: Configure backup log rotation
+  ansible.builtin.copy:
+    content: |
+      /var/log/homelab-backup.log {
+        weekly
+        rotate 4
+        compress
+        missingok
+        notifempty
+      }
+    dest: /etc/logrotate.d/homelab-backup
+    owner: root
+    group: root
+    mode: "0644"
+  tags: [backup]