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/templates/sshd_config.j2

@@ -0,0 +1,26 @@
+# Managed by Ansible - do not edit manually
+Port {{ sshd_port }}
+AddressFamily any
+ListenAddress 0.0.0.0
+ListenAddress ::
+
+HostKey /etc/ssh/ssh_host_rsa_key
+HostKey /etc/ssh/ssh_host_ecdsa_key
+HostKey /etc/ssh/ssh_host_ed25519_key
+
+PermitRootLogin {{ sshd_permit_root }}
+PubkeyAuthentication {{ sshd_pubkey_auth }}
+PasswordAuthentication {{ sshd_password_auth }}
+ChallengeResponseAuthentication no
+UsePAM yes
+
+X11Forwarding no
+PrintMotd no
+AcceptEnv LANG LC_*
+
+MaxAuthTries 3
+MaxSessions 10
+ClientAliveInterval 300
+ClientAliveCountMax 2
+
+Subsystem sftp /usr/lib/openssh/sftp-server