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

requirements.yml

@@ -0,0 +1,14 @@
+---
+collections:
+  - name: community.docker
+    version: ">=3.4.0"
+  - name: community.general
+    version: ">=7.0.0"
+  - name: ansible.posix
+    version: ">=1.5.0"
+
+roles:
+  - name: geerlingguy.docker
+    version: "6.1.0"
+  - name: geerlingguy.pip
+    version: "2.2.0"