Complete production-ready Caddy infrastructure with security hardening

- Add comprehensive Caddy role with HTTPS/TLS, DNS challenges, and systemd security
- Implement optimized systemd overrides with enhanced security restrictions
- Create detailed documentation with usage examples and variable references
- Establish proper Ansible configuration with vault integration
- Update site.yml for infrastructure orchestration with role-based deployment
- Add host-specific configuration structure for scalable multi-environment setup

roles/caddy/handlers/main.yml

@@ -0,0 +1,20 @@
+---
+- name: reload systemd
+  systemd:
+    daemon_reload: yes
+
+- name: restart caddy
+  systemd:
+    name: caddy
+    state: restarted
+    daemon_reload: yes
+
+- name: reload caddy
+  systemd:
+    name: caddy
+    state: reloaded
+
+- name: stop caddy
+  systemd:
+    name: caddy
+    state: stopped