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/tasks/main.yml

@@ -0,0 +1,98 @@
+---
+- name: Set hostname
+  ansible.builtin.hostname:
+    name: "{{ common_hostname }}"
+  tags: [common, hostname]
+
+- name: Set timezone
+  community.general.timezone:
+    name: "{{ common_timezone }}"
+  tags: [common, timezone]
+
+- name: Update apt cache
+  ansible.builtin.apt:
+    update_cache: true
+    cache_valid_time: 3600
+  tags: [common, packages]
+
+- name: Install common packages
+  ansible.builtin.apt:
+    name: "{{ common_packages }}"
+    state: present
+  tags: [common, packages]
+
+- name: Upgrade all packages
+  ansible.builtin.apt:
+    upgrade: safe
+  tags: [common, packages, upgrade]
+  when: apt_upgrade | default(false) | bool
+
+- name: Configure SSH daemon
+  ansible.builtin.template:
+    src: sshd_config.j2
+    dest: /etc/ssh/sshd_config
+    owner: root
+    group: root
+    mode: "0644"
+    validate: "sshd -t -f %s"
+  notify: Restart sshd
+  tags: [common, ssh]
+
+- name: Ensure SSH is running
+  ansible.builtin.systemd:
+    name: sshd
+    state: started
+    enabled: true
+  tags: [common, ssh]
+
+- name: Configure UFW defaults
+  community.general.ufw:
+    direction: incoming
+    policy: deny
+  tags: [common, firewall]
+
+- name: Allow SSH through UFW
+  community.general.ufw:
+    rule: allow
+    port: "{{ sshd_port }}"
+    proto: tcp
+  tags: [common, firewall]
+
+- name: Allow traffic from local network
+  community.general.ufw:
+    rule: allow
+    src: 192.168.86.0/24
+  tags: [common, firewall]
+
+- name: Enable UFW
+  community.general.ufw:
+    state: enabled
+  tags: [common, firewall]
+
+- name: Configure fail2ban
+  ansible.builtin.systemd:
+    name: fail2ban
+    state: started
+    enabled: true
+  tags: [common, security]
+
+- name: Set vm.swappiness
+  ansible.posix.sysctl:
+    name: vm.swappiness
+    value: "10"
+    state: present
+    reload: true
+  tags: [common, sysctl]
+
+- name: Configure NTP
+  ansible.builtin.apt:
+    name: chrony
+    state: present
+  tags: [common, ntp]
+
+- name: Start chrony
+  ansible.builtin.systemd:
+    name: chrony
+    state: started
+    enabled: true
+  tags: [common, ntp]