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/common/defaults/main.yml

@@ -0,0 +1,24 @@
+---
+common_packages:
+  - htop
+  - iotop
+  - curl
+  - wget
+  - git
+  - jq
+  - unzip
+  - net-tools
+  - ncdu
+  - tmux
+  - rsync
+  - lsof
+  - vim
+  - ufw
+  - fail2ban
+
+common_timezone: America/Chicago
+common_hostname: "{{ hostname | default(inventory_hostname) }}"
+sshd_port: 22
+sshd_permit_root: "no"
+sshd_password_auth: "no"
+sshd_pubkey_auth: "yes"