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/templates/backup.sh.j2

@@ -0,0 +1,42 @@
+#!/bin/bash
+# Homelab Backup Script - Managed by Ansible
+# Host: {{ inventory_hostname }}
+
+set -euo pipefail
+
+BACKUP_DIR="{{ backup_destination }}"
+DATE=$(date +%Y%m%d_%H%M%S)
+HOSTNAME="{{ inventory_hostname }}"
+BACKUP_FILE="${BACKUP_DIR}/${HOSTNAME}_${DATE}.tar.gz"
+RETENTION_DAYS="{{ backup_retention_days }}"
+
+echo "=== Backup started at $(date) ==="
+echo "Destination: ${BACKUP_FILE}"
+
+# Pre-backup commands
+{% for cmd in backup_pre_commands %}
+echo "Running pre-backup: {{ cmd }}"
+{{ cmd }}
+{% endfor %}
+
+# Create backup
+tar czf "${BACKUP_FILE}" \
+{% for source in backup_sources %}
+  {{ source }} \
+{% endfor %}
+  2>/dev/null || true
+
+BACKUP_SIZE=$(du -sh "${BACKUP_FILE}" | cut -f1)
+echo "Backup created: ${BACKUP_FILE} (${BACKUP_SIZE})"
+
+# Post-backup commands
+{% for cmd in backup_post_commands %}
+echo "Running post-backup: {{ cmd }}"
+{{ cmd }}
+{% endfor %}
+
+# Cleanup old backups
+echo "Removing backups older than ${RETENTION_DAYS} days..."
+find "${BACKUP_DIR}" -name "${HOSTNAME}_*.tar.gz" -mtime +${RETENTION_DAYS} -delete
+
+echo "=== Backup completed at $(date) ==="