fix: resolve all YAML linting errors in playbooks and inventories

- Fix line length violations by using YAML folded strings (>-)
- Remove trailing whitespace from all files
- Add missing document start markers (---) to inventory files
- Improve readability of long Jinja2 template expressions
- Maintain YAML linting compliance for production-ready code

All files now pass yamllint validation successfully.

inventory/docker.yml

@@ -1,6 +1,6 @@
 # Docker Testing Environment Inventory
 # For testing deployments before production
-
+---
 wordpress_servers:
   hosts:
     docker-test:
@@ -10,22 +10,22 @@ wordpress_servers:
       ansible_ssh_pass: ansible123
       ansible_become_pass: ansible123
       domain_name: localhost
-      
+
       # SSL Configuration (usually disabled for testing)
       ssl_enabled: false
-      
+
       # WordPress Database (Test credentials)
       mysql_root_password: "test_root_password"
       wordpress_db_name: "wordpress"
       wordpress_db_user: "wp_user"
       wordpress_db_password: "test_wp_password"
-      
+
       # WordPress Admin (Test credentials)
       wp_admin_user: "admin"
       wp_admin_password: "test_admin_password"
       wp_admin_email: "admin@localhost"
       wp_site_title: "Test WordPress Site"
-      
+
       # Ultimate Features (for testing Ultimate-Playbook)
       enable_redis: true
       enable_opcache: true