feat: add WordPress as runtime — Dockerfile, K8s env vars, wp-content PVC, frontend UI

Backend:
- Add WORDPRESS to AppRuntime enum
- Add wordpressDockerfile() using wordpress:6-php8.3-apache base image
  with custom theme/plugin/wp-content merge support
- Add WordPress-specific K8s env vars (WORDPRESS_DB_HOST, WORDPRESS_DB_USER,
  WORDPRESS_DB_PASSWORD, WORDPRESS_DB_NAME, WORDPRESS_TABLE_PREFIX)
- Create wp-content PersistentVolumeClaim (2Gi) for WordPress deployments
- Mount wp-content PVC in deployment container at /var/www/html/wp-content

Frontend:
- Add 'wordpress' to runtime type unions (Application, CreateApplicationDto)
- Add WordPress runtime card in deploy page (port 80, blue icon)
- Auto-select MySQL database when WordPress is chosen, disable other DB options
- Show Persian hint 'وردپرس به MySQL نیاز دارد' when WordPress selected
- Update all runtime icon colors across dashboard, apps, admin/apps pages
  to show blue-600 for WordPress

frontend/src/app/dashboard/apps/[id]/page.tsx

@@ -358,7 +358,7 @@ export default function AppDetailPage() {
       <div className="flex flex-col sm:flex-row sm:items-center gap-4">
         <div className="flex items-center gap-4 flex-1 min-w-0">
           <div className="w-14 h-14 rounded-2xl bg-primary-50 flex items-center justify-center shrink-0">
-            <Hexagon className={`w-7 h-7 ${app.runtime === 'nodejs' ? 'text-green-500' : 'text-orange-500'}`} />
+            <Hexagon className={`w-7 h-7 ${app.runtime === 'nodejs' ? 'text-green-500' : app.runtime === 'wordpress' ? 'text-blue-600' : 'text-orange-500'}`} />
           </div>
           <div className="min-w-0">
             <div className="flex items-center gap-2 flex-wrap">